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General Information => Troubleshooting => Topic started by: Rising on April 01, 2013, 07:49:08 pm
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Okay so I've been meaning to get some feedback on this issue for awhile, but it just hasn't seemed to be a big problem till tonight. I've noticed with this engine that I've been getting some throttle surge as I accelerate. Mostly noticeable in 1-3 as they are shorter gears. I.E. throttle position is static and the engine seems to climb to a certain rpm, then it feels like a goosed the throttle for about 150 rpms and then goes back to normal acceleration. This is pretty annoying when driving around casually in 1-2 around neighborhoods and also when trying to save gas and being light on the throttle. ::)
But tonight it started to worry me because right at that rpm it starts to accelerate and makes an awful noise. Like BAD. Grindy knocky sounds. So now I'm worried that another engine is going to fail me :( Is this slight runaway? Failing pump? Failing engine? What's going on here?
I just got home and I'm too tired to write more. I'll try to get a video and investigate more tomorrow. . . hopefully someone has some insight on this.
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SURGING the man says. Wait while I apply the cranial enhancer mega force analyzer. Chin strap on and powered up.
So, I think you are on to it somewhat in that it may be related to fuel. But not from an outside source like crankcase. Although I wouldn't rule out that possibility until you yank the hose off the intake for a couple days and see if that helps.
I am going with fuel pump here. It is sticky in side and when it lets go the pressure builds and you get a bump in the advance. It may very well be that advance piston it self. Ever have the IP apart? How about those little bitty pieces of metal that slide in and out of the vane pump. They sticking? Don't tell me you have an air leak on the pump.
The grindy knocky sounds would have me looking at the transmission and axles for worn or binding parts. They hold then pop out and all is good then bind up again some how.
Transmission full of oil?
OK that is all the battery life I have in the thinking cap for now.
Anyone else care to thow knives at the woman on the rotating wheel?
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Surging is usually caused by loose injection pump bolts.
Either the 4 that hold it to the brackets or the others that hold the bracket to the block.
Look down behind the pump and see if those two bracket bolts are still there. I blue lock-tite those now.
Usually occurs with a vibrating accelerator peddle.
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^^ x2, from personal experience....
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Okay excellent work with the cranial enhancers. A. The fuel pump makes sense. I will check the bolts today but I don't feel like that is it. Its very consistent to be loose bolts. Its always the exact same rpm range. But a sticking advance piston makes tons of sense. I actually thought that as soon as I woke up this morning with a clear head.
Okay so I've never done anything to my injection pump. The biggest thing I've done besides setting the timing is adjusting the fuel screw and the idle set screw. (For reference I turned the fuel screw down a 1/4 turn to save some more fuel ;D ) How do air leaks form/how would I know? They are some bubbles at my injector return hoses but i always thought maybe my hoses were weird or something.
What about running something through the injection pump? Should I run atf or sea foam straight through it? How could I unstick some stickiness? Or maybe its time for a Turbo diesel pump ;D;D;D
As for the grinding to clarify. It happens in neutral parked with me at the front of the engine and only as the rpms do their surging gig. But nothing at idle or slight throttle.
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Bubbles in the injector returns are normal.
Clear fuel lines from the filter and to the return line will show if/where air is entering the system. About 3' of tygon tubing will cover both runs.
(http://img200.imageshack.us/img200/6132/airfrompump.jpg)
The grinding noise is a concern... does this happen even when the engine is cold?
I'd take out the IP OUT bolt and look for grunge in the screen, then clean it with brake parts spray.
Then I'd run a can or two of Diesel Purge - stick both tubes from the IP into the can and run it till the cleaner is consumed. The cleaner will circulate back to the can a lot while the engine is burning it as fuel.
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Okay well as usual I'm dumb and missed something obvious. Haha. Fat mobile hit the nail on the head. The back bolt by the oil dip stick was missing from the injection pump and after sourcing a new bolt and tightening everything up. The surfing and the rattling noise are gone.
Grinding was a bit of a stretch on the noise i guess as it was definitely caused by the loose IP. Glad I caught this though.
Anyway I still want to run a bit of diesel purge through it for the heck of it. I just replaced my return line with solid line. But my supply line is already clear. No bubbles coming from the filter.
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The biggest thing I've done besides setting the timing is adjusting the fuel screw and the idle set screw. (For reference I turned the fuel screw down a 1/4 turn to save some more fuel ;D )
FWIW, you have saved no fuel by doing this modification. ;D. This is a diesel with no throttle plate, there always needs to be x amount of minimum fuel for y amount of RPM. So if you are still turning the same RPM, then you are still injecting the exact same amount of fuel you just have to push the pedal further now.
If you REALLY want to save more fuel, take the right foot 1/4" off the pedal at all times. ;) this will save more than you think haha.
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The biggest thing I've done besides setting the timing is adjusting the fuel screw and the idle set screw. (For reference I turned the fuel screw down a 1/4 turn to save some more fuel ;D )
FWIW, you have saved no fuel by doing this modification. ;D. This is a diesel with no throttle plate, there always needs to be x amount of minimum fuel for y amount of RPM. So if you are still turning the same RPM, then you are still injecting the exact same amount of fuel you just have to push the pedal further now.
If you REALLY want to save more fuel, take the right foot 1/4" off the pedal at all times. ;) this will save more than you think haha.
Surprisingly I believe I knew this already haha. But good info for everyone anyway.
I understood that right foot = fuel injection quantity. However when I added a 1/4 turn to the fuel screw my fuel mileage took a hit. Presumably due to added fun factor. Haha. Backing off a 1/4 turn has netted me my highest mileage tank yet at 48 MPG. . . So somehow I need to learn to control myself haha.
But until then I've physically limited my fuel consumption in my quest for 50 MPG. Ill probably get tired of it in a week and bump it back up. Baha.
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Are you driving slower?? As I said it takes the same amount of fuel regardless to hold a 1.6L engine at a certain rpm.
Congrats on the tank mileage, but I think its just because you are driving slower lol.
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And the magic word is???
Smileage.
a Hagarism if you didn't already know.
Slow and easy always wins the MPG race.
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Are you driving slower?? As I said it takes the same amount of fuel regardless to hold a 1.6L engine at a certain rpm.
There is the issue of overfueling...
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I don't think so. For if he has lowered the max fuel, the same fueling can be achieved by pushing the pedal a little further. 1/4 turn is not really surmountable in terms of overall fueling, and the throttle could easily overcome that amount.
I don't think he was near 48mpg if he were cruising in the higher RPM's where over fueling is more likely.
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FWIW, you have saved no fuel by doing this modification. ;D. This is a diesel with no throttle plate, there always needs to be x amount of minimum fuel for y amount of RPM. So if you are still turning the same RPM, then you are still injecting the exact same amount of fuel you just have to push the pedal further now.
I partially disagree. When accelerating you hit max fuel quite often, even if you aren't trying (50HP, what do you expect?). By limiting the amount of max fuel there is the potential to save fuel. It really depends on driving style though.
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I was not accounting for acceleration to be part of the equation, I don't/didn't accelerate my 1.6TD/1.6D at full fueling (the most amount of pedal with no smoke belching) from stop lights lol.
I assumed it was a pure basis of cruising said car at said rpm, at said speed. Same speed/rpm will require the same fuel regardless.
Limiting max fuel upon acceleration would help to save some fuel, but enough to noticeably bump up a tanks average?? and by only turning 1/4 turn? Skeptical I am.
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Like I said, it depends on your driving style.
I know it would have made a difference for me, but that's boring and not worth the 0.2L/100kms;)
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I definitely could understand your logic jeremy on a strictly highway driving section. However my daily commute is entirely through towns and back roads. Lots of starts and stops. Having less fuel throughout the powerband makes it far harder to use as much fuel without just flooring it everywhere. Which I never do.
I definitely don't argue that I'm driving slower and accelerating slower and the total fuel used could be achieved with the fuel screw farther in. All those are completely true.. but having less fuel to play with seems to help me manage it better anyway.
Something in my mind says 100% or 80% throttle is bad. So I naturally never press the pedal that far. So turning down the fuel for me makes 80% throttle and below the equivalent of 70% throttle and below kinda. Idk if that makes sense...
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Okay so now I think I'm losing my mind. This issue seems to have partially returned with the part throttle surging since doing my timing belt and Gov Mod. It actually seems a bit more annoying this time. But I've triple checked all the bolts on the IP and none of them are responsible. So is it possible I did actually mess something up on the gov mod?
Also when it surges part throttle it's a serious increase in power... How can I make my diesel run like that all the time? Haha. Like is that a sign I need more advance? And why is this only a part throttle issue. Doesn't seem as noticeable (could just be me intending to go fast vs. Surprise) at WOT. EGTs definitely jump when it happens too but that could just be the revs...
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Are you sure you shimmed the correct spring on the governor? Did you shim 1 or 2 springs?
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Yeah it kind of sounds like he shimmed the intermediate spring doesn't it.
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Okay so I've never done anything to my injection pump. The biggest thing I've done besides setting the timing is adjusting the fuel screw and the idle set screw. (For reference I turned the fuel screw down a 1/4 turn to save some more fuel
as several other people quoted driving habits effect fuel mileage a lot, using 1/2 throttle to 2/3 throttle is best, 3/4 throttle should be your max throttle mostly; also keep your revs up(some) such as in 3rd in my 1.6na, I will at 1/2to3/4 throttle accelerate to 40 mph and in 4th up to 45 to 50mph and then get into 5th. keeping the revs up some with moderate throttle you will accelerate quicker and have less load on engine as a norm; there by saving some fuel or more. you may notice a difference in 1 tank and it can get better as you find the groove and the engine gets used to being treated in an easy manner.!
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I just shimmed the longest spring(main spring I believe). Like 3 small washers... I read through through the gov mod sticky like 5 times first. So I read warnings against shimming the intermediate.
I was looking at pictures the whole time and didn't even take the governor all the way apart. I just pulled the snap ring and pulled off the main spring replaced with washers and out it back together.
Okay so I've never done anything to my injection pump. The biggest thing I've done besides setting the timing is adjusting the fuel screw and the idle set screw. (For reference I turned the fuel screw down a 1/4 turn to save some more fuel
as several other people quoted driving habits effect fuel mileage a lot, using 1/2 throttle to 2/3 throttle is best, 3/4 throttle should be your max throttle mostly; also keep your revs up(some) such as in 3rd in my 1.6na, I will at 1/2to3/4 throttle accelerate to 40 mph and in 4th up to 45 to 50mph and then get into 5th. keeping the revs up some with moderate throttle you will accelerate quicker and have less load on engine as a norm; there by saving some fuel or more. you may notice a difference in 1 tank and it can get better as you find the groove and the engine gets used to being treated in an easy manner.!
Good tips! I've been wondering about low vs. High rpms and shift points for economy. Engine does seem happiest under slightly elevated speeds. Not lugging it all over the place. . .
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there are a lot of other things that can help also with fuel mileage, takes about a day to maintain all these things; for instance engine oil, using a 5w-30 synthetic, if your car doesn't call for 5w-40syn specifically I like to run 5w-30 in mine(mk2). trans fluid, change every few years, syn fluid is beneficial. axles and things like wheel bearings keep greased, syn grease helps with mpg and part wear. I don't use syn grease currently in my cv joints, if you do make sure the syn grease specifically works in cv joints. rear wheel bearings the small outer needs to be packed and readjusted about 2x a year.(mk1!mk2!&mk3's).a good alignment, good tires proper pressure in tires, and even good working brakes all add to mpg and reliability.
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ooh, though if you haven't had a full synthetic running regularly don't go and throw a syn in the engine, everything else its fine.
also a lot of the model cars the diesels the 5th gear is specifically designed for 55mph, the designers back then didn't see the 55mph law being changed, if you have one of these trans, I have 2 of them, even going over 55 to 56mph there is a drop in fuel economy.
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Melt those transmissions into a slug of metal and scrap them. Do not let another experience a transmission designed for best economy at 55 mph. Or only sell to old men that can't drive that fast anyway.
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heheh, although the Trans's are very reliable, as long as you change fresh fluid every few years, and don't shift hard, even with some beating-on they can still last,, I have never had a vw trans go bad on me, as long as its like im not spinning tires or too much pop on the clutch, that's 10 or so cars I ve had over the years and I cannt call any not any problem with a trans(manual), ;D, some were gas, I still have a gas a-c trans.
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Good to know. Synthetic in gearbox is worth it? Why wouldn't I put syn in there? Didn't quite get that part of your post.
Any other ideas on this problem? Can't find anything else I did weird... Scared to pull pump back apart..
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maybe a couple of reasons not to use synthetic; 1 in an engine that has over 100k miles and hasn't used synthetic regularly its a no-no in a motor; 2 in a trans, I d use a trans flush, use properly and if trans fluid drains clear, you Can use syn in trans, if trans fluid drains dirty, refill with a good conv fluid. for wheel bearings it works pretty good. but im not assuming for you, if you don't know too much about syn lubes its up to your discretion, im a syn man and have been since my 1st or 2nd car. Valvoline for instance is average for the course, but you can find it easily in an automotive store, Castrol I figure is similar; for the really strong stuff, you cannt find in most stores, you ll have to do some research.
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Okay so this surging problem has changed. Now it's a bucking on and off problem whenever I'm in those rev ranges. It just starts surging on and off pretty quickly and makes it rather unpleasant to drive. I followed the pictures all along the gov mod thread and everything looked the same. I'm back onto or coasters idea about the sticky advance piston. Not really sure though. I could open the pump back up and post pics if you guys think that is the next place for me to go?
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I don't know...Are you sure you indexed the shaft correctly?
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I probably already asked but.,, are all the mounting bolts tight,.. including the ones holding the i-pump brackets to the block?
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I don't know...Are you sure you indexed the shaft correctly?
Well I believe so yes. But I guess I could try rotating a spline one way and another and see what happens. Can I do that without loosing all the springs again?
I probably already asked but.,, are all the mounting bolts tight,.. including the ones holding the i-pump brackets to the block?
That is a very good question. Haven't even thought about that. I'll check in the morning.
Could a loose tbelt cause this? I was watching the tbelt today and it seems like when it surges the t belt between the cam pulley and the tensioners seems to kinda flap some. Is that normal? Timing belt tension is confusing to me with the whole 60° thing...
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also a lot of the model cars the diesels the 5th gear is specifically designed for 55mph, the designers back then didn't see the 55mph law being changed, if you have one of these trans, I have 2 of them, even going over 55 to 56mph there is a drop in fuel economy.
Melt those transmissions into a slug of metal and scrap them. Do not let another experience a transmission designed for best economy at 55 mph. Or only sell to old men that can't drive that fast anyway.
::)
The 55 limit was universally despised and nobody thought it would stay.
The difference between an AVX and AGS/AOP/ACH in 5th gear is only about 200rpm.
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It sounds like air to me, or a fuel restriction. Are you able to observe the feed and return line when it is bucking to see if there are any bubbles?
Can you hook it up to a jerry can and see how it runs?
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My feed line is clear. I can rev it up and feel the pump take off even in neutral.
The return line is black.. I do have some clear PVC tubing around that I might be able to mock up for a test run... Air could make sense. If the pump top isn't sealing right could that cause air to enter at a certain rpm? I was having trouble with the new seal for the pump top. Seemed like it was too big. Spent a long time messing with it...
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Not likely the top... that has something like positive 40-140psi. Air is usually drawn in at the inlet fitting and the mainshaft seal.
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There are 2 styles of top cover seals for these pumps. One has ribs, the other is similar to a flat o-ring. Did the new one match the old one?
This likely isn't your issue though, as this part of the pump is under pressure as the other Tyler stated.
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I don't know...Are you sure you indexed the shaft correctly?
Well I believe so yes. But I guess I could try rotating a spline one way and another and see what happens. Can I do that without loosing all the springs again?
I probably already asked but.,, are all the mounting bolts tight,.. including the ones holding the i-pump brackets to the block?
That is a very good question. Haven't even thought about that. I'll check in the morning.
Could a loose tbelt cause this? I was watching the tbelt today and it seems like when it surges the t belt between the cam pulley and the tensioners seems to kinda flap some. Is that normal? Timing belt tension is confusing to me with the whole 60° thing...
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If the T-belt is loose it's not going to be loose between the cam and tensioner.
Did you rotate the cam down instead of up when tensioning?
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I don't know...Are you sure you indexed the shaft correctly?
Well I believe so yes. But I guess I could try rotating a spline one way and another and see what happens. Can I do that without loosing all the springs again?
I probably already asked but.,, are all the mounting bolts tight,.. including the ones holding the i-pump brackets to the block?
That is a very good question. Haven't even thought about that. I'll check in the morning.
Could a loose tbelt cause this? I was watching the tbelt today and it seems like when it surges the t belt between the cam pulley and the tensioners seems to kinda flap some. Is that normal? Timing belt tension is confusing to me with the whole 60° thing...
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If the T-belt is loose it's not going to be loose between the cam and tensioner.
Did you rotate the cam down instead of up when tensioning?
I'm gonna go ahead and show my ignorance. I didn't know I was supposed to rotate the cam pulley while tensioning. Im almost positive I just left the can pulley loose cam lock in place cam pulley bolt just barely loose (after knocking pulley off and back on) IP pin in, rotated the crank a bit past TDC and then tensioned it back on to TDC, checked belt tension, rinse repeat until I was satisfied with timing and belt tension. Then snugged the cam pulley up, verified timing, removed locks, rotated by hand a few times and started it up. . .
Did I miss a step?
The old pump gasket didn't have as defined of ribs but it definitely had ribs... The new one had a lot thicker ribs it seemed. I figured that was just new verse old shrunken rubber.
Been a busy week. Hoping to check return line sometime tomorrow.
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If the method you followed had the cam lock, pump lock and crank shaft at TDC all together after rotating by hand.. You did it correctly.
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you want the round black seal in the kit for the pump lid, not the one with ribs.
the other poster is talking about which way you set the tensioner. as you face it one the side of the engine its supposed to be swung to the left and up.
also not sure if I'm reading you right on your timing job but how can you set tensioner to get all the belt slack out with the injection pump lock in? thats not what the book says to do.
i'm not smart enough to know what possible effects that may have if you say your timing marks are still lining up. there are people posting about doing mark and prey methods and driving their car off into the sunset :)
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If the method you followed had the cam lock, pump lock and crank shaft at TDC all together after rotating by hand.. You did it correctly.
Yep! Rotated through 2 or 3 times to double triple check. It all lines up.
you want the round black seal in the kit for the pump lid, not the one with ribs.
the other poster is talking about which way you set the tensioner. as you face it one the side of the engine its supposed to be swung to the left and up.
also not sure if I'm reading you right on your timing job but how can you set tensioner to get all the belt slack out with the injection pump lock in? thats not what the book says to do.
i'm not smart enough to know what possible effects that may have if you say your timing marks are still lining up. there are people posting about doing mark and prey methods and driving their car off into the sunset :)
Well the only seal I remember seeing that was shaped like the pump top seal was the one with ribs. Are you saying I should've used one of the circular seals?
Yeah I'm still not sure exactly what the proper method is... But I've changed several timing belts this way and never had a problem with timing. . . unless of course this is my first :-p
The problem seems to be getting better slowly by itself. Which is confusing. It started as a power surge. Then went to off and on power. Now its getting less noticible (or I'm just driving so as to completely avoid it..)
Gonna run the pump from a jerry can and post a video for you guys as soon as I can get a break on my other cars...
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Don't use the ribbed one, use the black round one. Use vaseline and form it into place.
Also again and the timing steps, that is what the bently says to do so I would imagine you aren't getting rid of all the slack of the belt by pinning the pump wile tensioning. I don't even know what that could do if it isn't tight on the intermediate shaft, etc. might be more likely to skip a tooth.
As far as your pump I always yank good stock runners to clean everything and reseal before service. Maybe you should do that and revert back to stock parts with stock fueling and get your car running well before messing with things.
I have got the surging thing with increasing fuel, never messed with the governor.
I have seen a pump so gooed up before that it wouldn't start without pedal and was jumpy and very slow reacting. Thank you veggie experiment :)
I tried diesel purge system on a couple cars that went down during an incident and this did not clean all the scale and floating debris inside the pump. It ended up taking 2 full day doses of atf to get those suckers to run again.
Broke those pumps down and still had to clean, especially the vane area.
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Weird I thought I already posted a response to this... Must've not come through.
Anyway. I found the problem. Oddly enough I went to adjust the timing (been playing with timing setting since I got my EGT ;) ) and the bottom bolt behind the crankshaft pulley wouldn't tighten back down. Eventually it just came all the way out of its little bracket thing in one long piece. Weird. So I need to find a new bracket timing do hickey or find a way to get a bolt down there... But I'm certain that was what was causing the surging issue. So The gov mod was not to blame! Other than perhaps my botched pump installation by not using fresh hardware.
Anyway I let the pump sit in atf overnight anyway since I had the opportunity and checked for bubbles with a clear return line. No bubbles and no leaks. I think this pump is still solid.
I'm still confused about The pump too gasket though. The previous gasket was a ribbed one like the new one. But you are saying I should've used an oring shaped into the slot. Did the previous owner use a wrong gasket too? Or what am I missing? Its sealing fine do I really need to pull it apart and replace it?
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I guess do what works.
Years ago when I tried to reseal my first pump I tried to use that ribbed seal because of the shape. But I recall it tweaking the pump lid so its the only reason I wondered if something was wrong.
Somebody told me to use the round one with vaseline and I have done so with 4+ pumps that are still in service and none of those pumps have leaked a drop.
Also on my used runners that I have pulled apart the seal was not ribbed.
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Years ago when I tried to reseal my first pump I tried to use that ribbed seal because of the shape. But I recall it tweaking the pump lid so its the only reason I wondered if something was wrong.
Somebody told me to use the round one with vaseline and I have done so with 4+ pumps that are still in service and none of those pumps have leaked a drop.
IIRC, some folks shave off the nubs and used the shaped seal. I have heard of the intact nubbed version being fat enough to crack the case.
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I've resealed probably close to 50-55 pumps and I have always used the shaped seal. Granted, I do shave the nubs off the side. Fits perfectly that way. I have never tried the other seal, so I cannot comment on those ones unfortunately.
If it works, doesn't matter to me. ;)
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Geez! Cracked pump tops from an itsy baby rubber seal! I never knew nubbs could cause so much trouble haha!
Well anyway if I take the cover off again maybe I'll pull the seal out and shave the nubbs. But again its sealing and doesn't appear to be cracked so I'm satisfied right now. ;) thanks again for all the help guys.
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There is a long stretch of thin aluminum running down the side of the lid,.. that's what broke out when I didn't shave the nubs enough.
I used to just snip them instead of razoring them close.
After that I switched to the flimsy lid seal and had problems with it staying in place while I lined up the LDA lever and idle RPM bump lever,
pinched one and it leaked so I went back to the shaped seal and started trimming with the razor blade.