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General Information => General => Topic started by: wadem on January 06, 2013, 09:55:30 am
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Hey guys, have been messing around with my timing over the last few weeks and have a question for the group. What are the cons, if any of having you timing too advanced? I have a 96 Jetta with the AAZ engine and the adjustable IP sprocket, so adjusting the timing and playing with it is very easy and maybe a 5 minute procedure everytime. What I have found with my engine is that it seems to run very well with what I determined to be a very advanced setting. Keep in mind that I have not used the timing tool on this procedure. The adjustable sprocket on the IP is very easily set by just lining up the adjustment holes and then locking the pump at that point while you secure the 3 bolts on the sprocket. I have done this for 2 years and have always been happy with the results. 2 weeks ago i decided to start advancing the timing in very small increments, like a 1/2mm at a time. What I have ended up with is a very happy engine, it starts better, no smoke (never was at old setting either), more power,etc. But again I think that it is too advanced, I assume this because at a slow acceleration until about 2200 rpm i am getting a slight pinging or Dieseling, that wasn't there before, but the car runs better in every other way.
So again just wondering what the cons of having a higher then normal advanced setting would be? Other then been a little louder, i can't think of any. So why would you ever want to run with a more retarded setting? Are there any pros to doing this? Why doesn't everyone run with a more advanced setting then published or listed in the book? I can't seem to find a reason, as my car is running the best its ever ran, OK a little louder but still great! ;D
Cheers
Wade
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Pros to retarded are emissions, and sound as you have noticed. Diesels in the 80-90's were loud and smokey.. and not many liked them in North America because of what GM screwed up with the Detroits ;) (yeah yeah, keep it in your pants GM guys, they were not a good engine design lol!)
I and many others run at the same spot you are right now, to where it starts to clack-clack as if you poured marbles down the intake. You are right on the brink of too much timing, but that is ok because it can't really hurt anything unless you go way overboard!
Try this, on a cold start pull out your COLD START handle prior to cranking. Do you notice the engine turns slower then with it in? If so, you are right on the brink of injecting fuel too soon. If it does slow it down you are injecting fuel so early it is fighting the piston on its way up in the bore! Which is no good for starting, perfect for warming up as it will be part of the compression as well, and not so good for high rpm use as it will be again fighting the piston.
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Listen to 8V on this. You are right on the edge of too much timing and an engine that it fighting itself to get started may not start of you are real cold. Pistons that are supposed to be going up and are compressing fuel that is burning at the high RPMs isn't doing you any good mileage wise.
Why don't we all run them higher than spec? Some should as the pump and such do wear over time, the new diesel is thinner than expected and some like that diesel clack. But others not so much, in fact they really don't like it at all so they would chose less advance.
You have the newer style injection system on it compared to us Old School guys and gals that are reliving our 80's. Injectors break under different pressures, and some like the retarded timing or advanced timing to compensate. Type of fuel makes a difference, WMO, WVO, or diesel be it bio or regular or stolen from the locomotive all can change the timing.
You have found the place to be for your Jetta. I would be very interested to know what your timing actually is compared to where you were before starting this process. And what the IP pressure is at both settings. Again timing changes with pressure or at start with the cold start lever.
So you have figured out the PRO side of the equation with advancing it. Advance it a bit more and listen to all that pinging for miles on end and you will figure out the CON side. By luck you stopped one setting short of demonstration I think.
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I set my pump by the book with the correct dial gauge setup and got lots of white smoke at startup. That was at 1.00. I bumped it up just a little more without using the gauge and it runs better and doesn't smoke hardly at all at startup.
I was thinking advanced timing would actually be better at high rpms, because since everything is sped up, wouldn't you want it injected a little sooner than at idle, or does the pump already take care of that? I know gas engines are more advanced at higher rpms, but that's a gas engine.
I like the diesel clatter, part of the reason I drive it. They kind of sound like a 2 stroke detroit to me, which I like. The 2-stroke detroits were great engines, but the 6.2 and 6.5 4-stroke were terrible.
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Smoke at idle means it was timed with retard. Now that you have that corrected you have to be careful of the advance that happens automatically as the RPM's increase. That is where the IP will produce more pressure and move the internals of the pump to get to the higher advanced timing. If you are already there with a manual move at idle then you will be too much advance at those higher RPM's and the piston will not like the earlier than should be entry of the fuel. Compression stroke will still be trying to finish and the power stroke will be on. Not efficient.
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Well I know I didn't move the pump much, just a hair, not so much the CS slows cranking speed, but I can still hear an increase in clatter when I pull it. I didn't want to advance too much, just enough to get rid of the embarrassing amounts of white smoke at startup, now it is down to a normal amount based on numerous videos I've watched...I don't care too much about performance, I'm going for mpg's although they have been down since it got real cold.
I don't think I can control how the pump advances as rpm's increase, can I?
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Just a hair or two is enough to jump 0.005"or more, and that is enough to make a substantial difference. Smoke is down and cold starts are good, then you are at the perfect spot :).
You can kind of control your pumps advance.. Depending, do you want it to advance quicker or slower and why do you want this?
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I have found that advanced timing reduces smoke at high rpm and increases fuel economy at highway speeds. I'm assuming the smoke is due to injector lag, which is why dynamic advance is implemented; but over time, it seems that the dynamic advance is not as limber, due to wear, weaker delivery valves, low internal IP pressure and out-of spec injectors. Advanced timing does make a bit more clatter in the lower rpm on my engines.
I have also noticed more clatter of a different tone when timing is overly retarded... pulling the CS lever seemed to reduce that clatter, so I advanced my IP and that made the situation better.
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I dont think I need to change how the pump advances at higher rpms. But I have noticed I get worse mpgs at 70mph vs 55 or lower (around 4-5 mpg difference), but I think that is fairly normal.
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Aero drag is the big hit. Drag increases to the cube of velocity.
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OK heres the scoop on my 96,
There was no distinguishable cranking speed change with the CS lever pulled VS not pulled. I as well can detect a slight clatter tone change when going from CS lever not pulled, to pulled. Also, the cold start does seem to make a difference on the quality of the start when it is cold(go figure). After it started today I immediately pushed the lever back in and although it continued to run smooth, there was a miss or misfire on a couple cylinders for about 30-45 seconds or so. This cleared right up upon activation of the CS lever again.
This leads me to believe that my setting is not too far advanced. If it was i dont think there would be any change when you pulled the CS lever, am I correct in thinking this?
Wade
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I tend to agree.
I'd say you're right on the button. All those details are what I consider optimal when assessing timing my tweeks.
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I tend to agree.
I'd say you're right on the button. All those details are what I consider optimal when assessing timing my tweeks.
I concur.
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OK! good news. The next test will be to see if MPG is the same as before, better, or worse.
Cheers
Wade
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The fact that the CS lever stops the missing and only advances enough to smooth out without being overly advanced, then I too agree you are timed perfectly for your exact setup.
Congratulations, you have just tackled and damn near mastered the most difficult thing this car/engine can and will throw at you :)
Being that you are doing this with some attack plan in mind.. would you mind referencing your new mileage and then maybe advancing a hair more again and seeing what happens? If it still stumbles cold without it pulled then maybe it could even use a bump more, not necessary.. but experimenting is always fun eh? lol
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I find that when the engine is timed as you describe that the mileage is much better at either speed 55 or 70. You know you will get much better at 55 put really, who drives that speed anyway. Be real about it and figure the mileage at what you normally drive. Then bump it a bit and drive some more.
Be aware that about halfway through that second tank you will end up having to follow someone driving at 45 forever before you can pass and that will mess up the mileage comparison. How do I know that? It happens to me all the time. Plenty of miles but seldom the same driving style, wind resistance, traffic, lack of accidents and such. I keep a book in the glove box and record every fillup and miles driven and still I see the variability over time.
But I think you got it where it can't get much better.
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OK heres the scoop on my 96,
There was no distinguishable cranking speed change with the CS lever pulled VS not pulled. I as well can detect a slight clatter tone change when going from CS lever not pulled, to pulled. Also, the cold start does seem to make a difference on the quality of the start when it is cold(go figure). After it started today I immediately pushed the lever back in and although it continued to run smooth, there was a miss or misfire on a couple cylinders for about 30-45 seconds or so. This cleared right up upon activation of the CS lever again.
This leads me to believe that my setting is not too far advanced. If it was i dont think there would be any change when you pulled the CS lever, am I correct in thinking this?
Wade
Yep that's where I'm at too
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I'm assuming the smoke is due to injector lag, which is why dynamic advance is implemented; but over time, it seems that the dynamic advance is not as limber, due to wear, weaker delivery valves, low internal IP pressure and out-of spec injectors.
I agree will all except with a little reservation regarding the injectors. If the spray pattern is degraded, then they add to the smoke, but as they wear their break pressure lowers which advances the timing reducing smoke.
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8V
Will do, i will run a few tanks of fuel through it as is, then maybe play somemore. This is the third VW diesel i have owned, but the first with the adjustable IP sprocket.....what a great device!
Wade
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I just did a reseal, gp's, electric fuel pump and other stuff to my 88.. I have literally never timed one as advanced as I set this one up and it was a horrible bugger to start cold.
However I only set it to 0.040".. it was so advanced that it would not start cold at all. Literally two minutes of cranking or more and nothing would happen.. a quick turn over, but no catch. I was stumped for a day or two, but then tonight I retarded it substantially before even attempting a start, so it was stone cold. It fired up within two cranks, and ran like a dream immediately. So what I thought was a moderately aged 446,000 km engine.. is still extremely tight. lol
So there is a CON to overly advanced I just learned tonight..
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Pros to retarded are emissions, and sound as you have noticed. Diesels in the 80-90's were loud and smokey.. and not many liked them in North America because of what GM screwed up with the Detroits ;) (yeah yeah, keep it in your pants GM guys, they were not a good engine design lol!)
I and many others run at the same spot you are right now, to where it starts to clack-clack as if you poured marbles down the intake. You are right on the brink of too much timing, but that is ok because it can't really hurt anything unless you go way overboard!
Try this, on a cold start pull out your COLD START handle prior to cranking. Do you notice the engine turns slower then with it in? If so, you are right on the brink of injecting fuel too soon. If it does slow it down you are injecting fuel so early it is fighting the piston on its way up in the bore! Which is no good for starting, perfect for warming up as it will be part of the compression as well, and not so good for high rpm use as it will be again fighting the piston.
if you are talking of the 5.7/6.2/6.5L engines, those were NOT Jimmys (Detroit Diesels)
the 5.7/6.2/6.5 were based off gasoline Oldsmobile engines.. they were junk. they gave diesels a bad name..
Detroits have no injection pump, and no intake valves.. they are also 2 cycle, and supercharged..
GM designed Detroit diesels in 1937.. they really didnt change the design much over the engines whole run.. they added turbos and intercoolers/aftercoolers to them..
sure, its said that these engines ARE detroits.. but they are NOT.. these engines share NOTHING in common with any other detroit diesel..
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All of GM's diesels were designed and put in to production by their own diesel division. Detroit Diesel.
:D
http://en.wikipedia.org/wiki/Detroit_Diesel_V8_engine
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Regarded by Hotrodding Mag as one of the worst engines of all time....
"The GM Corporate partners shared the grief associated with its diesel debacle of the early '80s. More often considered an Oldsmobile motor, this converted gasoline engine was used throughout the GM family, and even found its way into top-of-the-line Cadillacs, with disastrous results. Failures were commonplace, often including internal engine components. At the time, mechanics and service writers referred to warrantee repair orders as "A.F.A." - or Automatic Factory Acceptance, and each respective franchise had mountains of repair orders related to the 350 cid diesel."
http://www.popularhotrodding.com/features/0408phr_worst_automobile_engines/
Oldsmobile produced various diesel engines during the 1980s. The Oldsmobile diesel gained a reputation for unreliability and anemic performance that badly damaged the North American passenger diesel market for the next 20 years.[1][2] However, the strong blocks continue to see use in petrol-powered race engines.[3][4]
LF9
The LF9 is a 350 cu in (5,737 cc) diesel V8 produced from 1978-1985. This converted gasoline engine was the subject of many warranty repairs.[5][6] Earlier versions and those used in pickups produced 120 hp (89 kW) and 220 ft·lbf (300 N·m) torque, while later versions produced 105 hp (78 kW) and 205 ft·lbf (278 N·m) torque.
Applications;
350N 1978–1985 Chevrolet, Buick, Oldsmobile, Pontiac, Cadillac, and Checker Marathon cars
350N 1978–1980 GMC and Chevrolet light trucks "pickups"
https://en.wikipedia.org/wiki/Oldsmobile_Diesel_engine
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The 6.2/6.5 engine was not the same as the oldsmobile-based diesel. The 6.2/6.5 was a product of rushed design and production, but if they weren't abused and were taken care of, they would last
"This engine was never meant to be a power and torque competitor with Ford/International and Dodge/Cummins, but rather a simply designed workhorse engine that made credible power, achieved decent fuel economy and met emissions standards in half-ton trucks"
When people tried getting more power of them, is when they failed.
Detroit should've stayed with their 2-stroke diesel, that is what they are good at, unfortunately the epa hates them even more than 4-stroke diesels.
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Agreed, the 2 stroke stuff was and still is the bomb.. but unfortunately Detroit Diesel's name is also on the Oldsmodiesel lol.
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Agreed, the 2 stroke stuff was and still is the bomb.. but unfortunately Detroit Diesel's name is also on the Oldsmodiesel lol.
that does not make them REAL detroit diesels..
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The 6.2/6.5 were designed from the bottom up as a new diesel engine, but the 5.7 was based on an olds engine.
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The 6.2/6.5 were designed from the bottom up as a new diesel engine, but the 5.7 was based on an olds engine.
yes, and all of them were JUNK..
and none of them shared ANYTHING in common with a detroit diesel...
if you called a 6.2/6.5, a JIMMY to anyone who knew anything, you would get slapped..
Detroit Diesel may have had SOMETHING to do with the design of the engine, but it is NOT a Detroit Diesel..
Screamin' Jimmys are Direct injected 2-cycle diesels..
a GM IDI is 4 cycle, and indirect injected, much like our VWs, and mercedes..
Any REAL detroit diesel, has a supercharger..
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Totally agree with you there ;D
It could've been a lot better if they had spent some time testing the engine, but they didn't, so they couldn't fix all the faults.
On another note, I discovered my cold start cable housing was pulled out of the bracket and wouldn't let me return the cold start quiet all the way back even though the knob was all the way in, so that explains why I was suddenly getting worse mpg's that last couple weeks (which I thought was the cold weather...).
Half a tank with it back to normal and my mileage is better.
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I discovered my cold start cable housing was pulled out of the bracket... that explains why I was suddenly getting worse mpg's that last couple weeks
I saw that in your pix, but thought you were aware or in the middle of a procedure... :/
(http://i1295.photobucket.com/albums/b622/tyb525/Photo12311632_1.jpg)
Really shouldn't make much difference, unless you idle or stop-go a lot.
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I noticed it when I took the pic and thought I fixed it at the time, but it looks like I need a new bushing or something to secure it. I did notice a little less clack and a little better performance after pushing it all the way back. I do about 50/50 town and country driving every day.
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The CS cable is usually retained by a spring clip Satan designed when he was also working on e-clips and circlips.
(https://lh5.googleusercontent.com/-ei84AU8he38/UO4WdOJ6lJI/AAAAAAAAA5M/rHpyfHj_v-g/s800/IMG_9219.JPG)
Sometimes it's easier to install the CS cable before installing the IP.
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That must be what I'M missing. Maybe I can rig something else up until I can get one.
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The CS cable is usually retained by a spring clip Satan designed when he was also working on e-clips and circlips.
(https://lh5.googleusercontent.com/-ei84AU8he38/UO4WdOJ6lJI/AAAAAAAAA5M/rHpyfHj_v-g/s800/IMG_9219.JPG)
Sometimes it's easier to install the CS cable before installing the IP.
Dude your making me laugh my ass off. Really though I ended up screwing up my idle adjustment screw on my ip today so i had to loosen it to fix it and had to reset my timing so i checked it before i loosened it i was at .033in i bumped it up to .045in so much better.
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Ja, last week I knocked mine up to .053" and it took a few more cranks to light-off; so I backed off to .048" and it is starting on second rev (25F ambient) and seems to show very little smoke at highway speed.
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Ja, last week I knocked mine up to .053" and it took a few more cranks to light-off; so I backed off to .048" and it is starting on second rev (25F ambient) and seems to show very little smoke at highway speed.
What effect does advanced timing have on the EGT?
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.048 seems a tad high is that the spec for your engine or pump combo?
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I don't know what the spec for my engine would be. I have an eco motor with a TD injection pump. Ive always thought the books specs were a tad low.
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IIRC, .039 is spec for ECO & 85-86 TD.
But we're dealing with a 22yr-old engine/pump in this case (25-30yrs for my others). I started at spec, since I had the engine out... and I generally don't time with a dial-gauge, but rather by ear and performance. Since I still had the tools out, I took readings when I bumped the timing around.
Regarding EGTs... I can't say with any certainty, since I don't have an EGT gauge. My guess is head temps will rise with nailing, since the energy is not going into piston-stroke. (I presume nailing can happen for various reasons, not just advanced timing.)
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Ja, last week I knocked mine up to .053" and it took a few more cranks to light-off; so I backed off to .048" and it is starting on second rev (25F ambient) and seems to show very little smoke at highway speed.
What effect does advanced timing have on the EGT?
I know retarded timing will cause high EGTs.
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I discovered my cold start cable housing was pulled out of the bracket... that explains why I was suddenly getting worse mpg's that last couple weeks
I saw that in your pix, but thought you were aware or in the middle of a procedure... :/
(http://i1295.photobucket.com/albums/b622/tyb525/Photo12311632_1.jpg)
Really shouldn't make much difference, unless you idle or stop-go a lot.
Cold start cable being un-hooked will have ZERO affects on your power, mileage, or anything like that..
the cold start advance only operates at idle. if you give your engine any throttle AT ALL, that brings the advance piston up off the cold start advance mechanism..
nope, the cable being out of the bracket is NOT what is causing your lower-than-normal economy..
hows your fuel filter?
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Ja, last week I knocked mine up to .053" and it took a few more cranks to light-off; so I backed off to .048" and it is starting on second rev (25F ambient) and seems to show very little smoke at highway speed.
What effect does advanced timing have on the EGT?
REALLY advanced timing will cause COOL EGTs.. like you will barely be able to break 1000*
REALLY retarded timing will cause REALLY HOT EGTs... you will have the pyrometer buried by half throttle, and omg, the smoke...
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Its not unhooked.. its always on actually. Being that pushing the handle in would cause the sheathing to back off and the mechanism to stay "on". So any amount of idling, 400 rpm higher would kill economy.
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Well I clearly notice a difference in sound and performance when the cold start is pulled vs when it isn't, when driving at any rpm. Fuel filter was just changed less than 500 mi ago.
I have seen other examples of driving with the cold start on changing how the engine runs, so I don't think it only affects the engine at idle.
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So I don't think it only affects the engine at idle.
No it really does, it moves the advance piston about 1/8".. internal pump pressures moves it the rest of the inch of movement. Its really only good to about 1750 give or take. Then pump pressures pick up and move the piston.
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(https://lh6.googleusercontent.com/-InMd4lrpVDE/UO-GED_yEOI/AAAAAAAAA5c/eBggi7Fovqs/s800/Mech-KSB-graph.png)
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I timed my 88 1.6 TD to 0.040" and it was WAY too advanced to start cold.. I had to back the pump off like 1/4" in movement to come down to a suitable cold starting setting. I didn't put the gauge back in it, but its much lower than 0.040"
You must be dealing with some extremely worn engines ???
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Well that would explain why I could hear an increase in clatter to a point, then disappear in higher rpms. Just like without the cold start, only more clatter in the lower rpms.
My cold start doesn't really increase idle speed though, but from what you all are saying, it should. I never heard anyone say that till now though. It never has since I've had the car. But it does "increase the clatter" and definitely helps at startup. So if it doesn't increase the idle, what does that mean?
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You may have a pump without the idle increase part. Is it the Early 80's Rabbit in your picture?? If so, that pump does not have an idle bump on the cold start lever.
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Yep '81 NA. So that would make sense then.
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You must be dealing with some extremely worn engines ???
1991 ECO block & head. Compression was 420psi across the row before I changed the HG a couple weeks ago... haven't done another compression test, yet.
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'Ay but what of the pump and injectors, compression doesn't have 'much' to do with injection.
0.053" is 1.3462mm! that is insanely high lol.
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Ja, .053" was a bit much, but it started after 3sec cranking and ran pretty well after warming. Back to .048" and starts easily.
I haven't checked break pressures & IP internal pressure. Just happy it starts easily and runs well.
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so what effect does lower breaking pressute have one egt and on timing?
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AIUI, lower break pressure will inject earlier, advancing timing for that injector.
(I have very little info on this engine, I pulled it, slapped a HG on it and stuffed it in to my 85. No pop-tests, no IP pressures. Runs a shade chuggy, but doesn't miss.)
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looking like .045 timing is a touch to advanced for starting my engine below 30 degrees farenheit. On a warm day though it spins right off.
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The TD? or TDI?
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The TD? or TDI?
td. I wish the tdi was going still sitting in a pile in my Garage.
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looking like .045 timing is a touch to advanced for starting my engine below 30 degrees farenheit. On a warm day though it spins right off.
WHA?!
TOO MUCH timing to start cold?!
my engine starts great when its cold.. the more timing, the merrier..
isnt it TOO RETARDED of timing that messes shizz up?
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Maybe my compression sucks :'(
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Naw naw. I timed the 88 TD to 1.00mm and it was way to much. Anywhere under 35f was a 45 second cranking ordeal. Its now way way down from therr (didnt gauge it) as ivwent by ear while still just a fresh cold start. Starts perfectly regardless of temperature.
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Maybe if i finish pimping my glowplugs(wire up the e350 solenoid to the fuse box i have the plugs wired to.) the extra juice will help start it. If i hit the glow plugs a couple times makes cold start at this advance setting much easier. also if i pull out the c/s lever right as it fires off it helps. Seems like the advanced timing is great otherwise. above 35 or 40 it fires straight away. I also do have my idles set at 950+-25rpm and the cold start bump idle set at approx 12-1300 rpm.
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I just remembered I have a block heater duh!! I bet that will help..
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Here is an idea, knock the timing back... ??? There is no gain in having it up that high. If the engine cannot sustain combustion properly, what is it really helping with? lmao
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I know mine is above 1.00mm, and it fires 1st or 2nd revolution after glowing once. Even without the coldstart it will start down to 15deg (coldest I've started it), but won't stay running long unless I give it a little gas (diesel?).
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It is all based on wear and tear. If you have a tired pump that cannot pop the injectors properly, advancing the timing will help "cover that up".
I see that you live in IN, you use the metric in your pump timing.. am I to assume "15deg" is also in Celsius? Or 15F?
If it will not stay running after you start it with out pedal, then you (or someone else ;)) has been messing with the pump settings lol. Turn in the pumps throttle stop, just enough to settle the idle. This will increase tension on the idle spring in the governor setup.
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With the CS engaged it will stay running just fine without touching the pedal, but if I don't have the CS pulled I sometimes need to feather the pedal for a few seconds after startup. I haven't tach'd the idle speed but it seems normal to me, after listening to several other 1.6 NAs idling...but I did have to adjust the idle speed slightly after timing.
I only used the mm measurement cause that's what the book uses and my dial is metric. As far as temperature it's Fahrenheit, I haven't memorized the Celsius scale lol.
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If this is on your fuelly sig car, then you dont have an idle bump and you likely need some more advance if the CS smooths cold idle.
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Tomorrow is forecasted for below zero temps, with -25 F wind chill, we shall see how the rabbit starts without a block heater (haven't replaced it yet)
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what effect would a few degress of advanced cam timing have on a td?
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Probably bent valves? These are interference engines, and I do believe that would be disastrous.
HOWEVER, I could be wrong.. but I do think the cam needs to be precisely timed to the the crank.
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I'm backing off my timing to .81mm after installing 145bar injectors... I was getting a fair amount of nailing even after timing to .84mm.
I only have 200 miles on the first tank, but it starts fine, runs much more quietly and it seems to have a bit more pull in 2500 - 4500 rpm range (maybe I'm imagining it? ).
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Are these new/rebuilt injectors? (ie. are they all spraying properly and breaking at the same time?)
Interesting, so what.. my TD with 155bar injectors and 1.00mm is way too advanced for your ears lol ??? ;D
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They are spraying good, popping pretty close - I pulled them from my 85/86TD.
http://www.vwdiesel.net/forum/index.php?topic=21926.msg309463#msg309463
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Hmm, I do not usually take down mileage unless the car is doing unusually bad lol. I may have to adjust the 1.6's timing down down down and see what happens.
It was averaging about 900km for the tank all winter. Now you got me curious lol.. could it get better!?
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Could it get better? How many friends do you have on tap to push the car around town. Mileage could be a record setter. Forget that 100K VW that gets 261 MPG. Got the 1980 or 90s version that never needs filling.
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My personal goal is to tweek all my rigs to 50mpg or better. (All have bested 50mpg excl. the Westy.)
I'm curious to know more about EGTs rising as a result from retarded injection timing*.
My butt-dyno is telling me I'm getting less nailing and more boost... possibly from hotter exhaust gasses, as the combustion starts later?
*At some point, timing could be so retarded that fuel is still burning as the exh. valve opens, but how about before then.
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EGTs definitely rise with retarded timing, for exactly the reason you list - the more retarded the more combustion is still occurring at exhaust time.
Boost levels will be higher with timing retarded a bit, again for the same reason. Gasses still expanding as they enter the turbine = more force on the turbine = more boost pressure.
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