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Engine Specific Info and Questions => IDI Engine => Topic started by: vako on November 14, 2013, 01:05:59 pm
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hello, as you know i finished my rebuild 1 week ago :) there are used pistons + new rings and rebored block. i have also resealed the pump last winter, so now it is leak free. engine has very good compression (when warm, it starts up without glowplugs with no problem). but the problem i had before is still there :(
car idles smooth, without misfiring or shaking . but when rev go up to maybe 1500 it starts to shake a bit (it has a slight misfire i think) and somewhere above 2000-2500 it revs smoothly again. i have noisy transmission and i hear intermittent whining noise... and also feel the car twitching. i happens every time i get in the problematic rev zone ???
pump is timed to ~0.95mm, and fuel screw is set to the position where it does not smoke very much (only small puff of black smoke before the boost builds up). i have changed the filter jut before the rebuild, i thought it would solve the problem. i have slightly lighter flywheel and front pulley but i remember exactly that i did not have that problem 1 or 2 years ago, so it must not be the cause.
i have not removed the injectors yet.
what could you advise me, what can be causing this strange behaviour of the engine ? ??? could it be the injectors? or i should be looking for the problem somewhere else. the thing that misleads me is the fact that it idles well, and the problem starts only after revving it up a bit :o
cheers , vako ;D
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Are all 4 securing bolts present on the pump, in particular the one under the pump head?
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Are all 4 securing bolts present on the pump, in particular the one under the pump head?
do you mean pump mounting bolts? they are all tightened well (i had that problem 3 years ago and after that i always dounble check mounting bolts :D
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Try swapping the injectors around. Break the sequence,ie label 1 3 4 2 and swap a couple, ie 1 & 4, to give 4312. Check true difference by trying to insert into the sequence 134213421342.
No better? Check injectors operation:
Check leakoff flow rates by opening up all the barbs and plugging 'return' line to pump. Running temporary lines to a row of test-tubes is ideal, or I'd use 8 off, 5" stiff clear lines creating vertical manometers.
Check spray and break pressures after an overnight rest; this I personally find, reveals faulty injectors at their worst. Look for variations;D
Nothing showing up? Insert your spare, preserved in aspic, set of injectors 8)
No help? Slacken engine mount/s
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Try swapping the injectors around. Break the sequence,ie label 1 3 4 2 and swap a couple, ie 1 & 4, to give 4312. Check true difference by trying to insert into the sequence 134213421342.
No better? Check injectors operation:
Check leakoff flow rates by opening up all the barbs and plugging 'return' line to pump. Running temporary lines to a row of test-tubes is ideal, or I'd use 8 off, 5" stiff clear lines creating vertical manometers.
Check spray and break pressures after an overnight rest; this I personally find, reveals faulty injectors at their worst. Look for variations;D
Nothing showing up? Insert your spare, preserved in aspic, set of injectors 8)
No help? Slacken engine mount/s
what will i find out by swapping injectors? ??? compression is the same in all the cylinders. so there will not be "bad cylinder" there... :?
as for the return lines, do you mean to disconnect return lines from injectors and check how much fuel does each injector overflow?
can bad spray pattern on clogged injector be causing such uneven operation only in limited range of rpms? i know you have worked with plenty of vw diesels and did you have such case in your practice?
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Are all 4 securing bolts present on the pump, in particular the one under the pump head?
do you mean pump mounting bolts? they are all tightened well (i had that problem 3 years ago and after that i always dounble check mounting bolts :D
Yup, pump mounting bolts. :) The 4th one at the high pressure end of the pump gets left out a lot and it causes the pump to oscillate in its mount at around the RPM range that you are having issues. But it sounds like you have this covered.
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I guess it is fuel related some how. Either you are not getting enough through the lines, filter, or something. If you look at where the gov. starts to cut fuel it is right around that 2000=2200 rpm range. so you have enough fuel before and after per RPM, the most fuel you will have per rpm is right in that range. Since it was with both engines it is probably in the fuel lines from the tank to the filter or pick up screen since you changed the filter. Like all of these diagnosis run it from a bottle into and out of the pump, if it takes care of it then you can start cleaning out lines/filter/etc. if it doesn't start looking at your pump.
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i forgot to mention, harder i push accelerator pedal less if feel the "rough running" period but still feel it a bit..). it is expressed the most when i barely touch the pedal and when i'm driving gently. also there are no bubbles in return line.
i ran it from bottle (i used atf to "clean" the fueling system) still it feels the same in problematic rpm-s.
pump rear bolt is tightened well :D i learned my lesson two years ago :D
i'm really confused now ???
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Checking leak off volumes, eliminates one that may be leaking more than others and so injecting a different quantity. Running the engine at idle and then at the offending rpm could show a dynamic injector issue.
These engines have lots of harmonics, hence the ability to vibrate the ash tray or tool box in the back at different speeds.
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I guess I assumed since it was bad enough to rebuild that it was misfiring badly in your first post...How bad is it? Is it a misfire or is it just vibration? When you lightened the flywheel and pulley were they neutrally balanced? If not that maybe your entire problem. For example my entire engine is balanced from pulley, crank sprocket all the way to the clutch, PP, and fly wheel to less than 1 gram. But it still has vibrations especially when cold and what you could perceive as a misfire if you didn't know because of all of the lightened stuff I have. Let us know more.
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Checking leak off volumes, eliminates one that may be leaking more than others and so injecting a different quantity. Running the engine at idle and then at the offending rpm could show a dynamic injector issue.
These engines have lots of harmonics, hence the ability to vibrate the ash tray or tool box in the back at different speeds.
ok i will do the leakdown test as soon as i have time for that (i have to write an essay till tuesday, and then i will check the injectors) :D it can really give me some info about bad injector ;D
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I guess I assumed since it was bad enough to rebuild that it was misfiring badly in your first post...How bad is it? Is it a misfire or is it just vibration? When you lightened the flywheel and pulley were they neutrally balanced? If not that maybe your entire problem. For example my entire engine is balanced from pulley, crank sprocket all the way to the clutch, PP, and fly wheel to less than 1 gram. But it still has vibrations especially when cold and what you could perceive as a misfire if you didn't know because of all of the lightened stuff I have. Let us know more.
i forgot taht my "lightened" flywheel (that is just a flywheel from suzuki sidekick) was balanced after i did a rebore for fitting it on vw engine. it was balanced within 5 grams :D
i know how diesel misfire feels like (while the car is cold sometimes it missfires for 1 minute, if i did not have cold start lever out) on idle and cold missfire is felt very well, and in my case it is even feeld on drivers seat :D
on problematic revs in my case the engine just starts to wobble a bit. if it is smooth through the rev range and on idle, it just starts to move from side to side a bit on that revs (but it is not felt at all inside the car, if teh car is not in gear and driving)... it seems that there is no enough power of combustion in one of the cylinders, but the combustion is still happening.
i think that at first i will have to check the injector overflow rate and after that at least take off the injectors and check for pop pressure and spray pattern.
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i will post a video as soon as i take the car out of teh garage :D
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Will it do it in neutral?
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yes it does it in neutral too. but in neutral you can only see the engine move from side to side a bit, it is not felt while sitting in the car
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I'd also look at boost level at the point of trouble.
I would suspect the IP has some issue with the governor or enrichment linkage, but the injector testing is a good start to narrow the variables.
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today i noticed that when the engine is cold and i just start to move problematic rev range is quite narrow. but as the engine warms up the range starts t increase up to 800-1000revs maybe. i dont even know what can be causing temperature depended problem.
i've been searching for faulty injector symptoms all day long and did not find anything that would be informative for me...
will wynns diesel purge be able to clean nozzles if they are clogged?
i looked at my IP rebuild pics now 9rebuilt it lats winter). governer was assembled as it was before the rebuild, it only had one broken lever inside the pump (maybe that is a lever for air conditioning high idle), and also the broken piece was not in the pump :D
(http://vardzelashvili.com/imghost/images/49933IMG_8532_1600x1200_.jpg) (http://vardzelashvili.com/imghost/view.php?filename=49933IMG_8532_1600x1200_.jpg)(http://vardzelashvili.com/imghost/images/84653IMG_8533_1600x1200_.jpg) (http://vardzelashvili.com/imghost/view.php?filename=84653IMG_8533_1600x1200_.jpg)(http://vardzelashvili.com/imghost/images/11483IMG_8535_1600x1200_.jpg) (http://vardzelashvili.com/imghost/view.php?filename=11483IMG_8535_1600x1200_.jpg)(http://vardzelashvili.com/imghost/images/83883IMG_8536_1600x1200_.jpg) (http://vardzelashvili.com/imghost/view.php?filename=83883IMG_8536_1600x1200_.jpg)(http://vardzelashvili.com/imghost/images/33313IMG_8537_1600x1200_.jpg) (http://vardzelashvili.com/imghost/view.php?filename=33313IMG_8537_1600x1200_.jpg)(http://vardzelashvili.com/imghost/images/10428IMG_8540_1600x1200_.jpg) (http://vardzelashvili.com/imghost/view.php?filename=10428IMG_8540_1600x1200_.jpg)
(http://vardzelashvili.com/imghost/images/75694IMG_8552_1600x1200_.jpg) (http://vardzelashvili.com/imghost/view.php?filename=75694IMG_8552_1600x1200_.jpg)
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Modify the governor while your in there!
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i was thinking about the governer mod when i had the pump apart. but in the mud sometimes you need to have rev limiter which is gone after the mod :D
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yes it does it in neutral too. but in neutral you can only see the engine move from side to side a bit, it is not felt while sitting in the car
You might be able to isolate it to one injector or delivery valve by swapping things around and running with one disabled.
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The rev limiter is still there - I used a small shim and mine kicks in at about 4500 on my 1.6td. I don't think it will rev over about 4900 no matter what - at least I've never done it. Hmm... Maybe now that I'm done with the engine.....
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Stock governor should hold the engine at ~5350 with the foot to the floor in neutral from factory.
If you have modified the assembly to make the springs stiffer, this number will surely be higher.
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Yeah I was talking about in gear pulling the car...
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I don't think it will rev over about 4900 no matter what - at least I've never done it.
And I read your mind how? ;)
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a little update, today i had my injectors tested... all of them were at 145 :-\ only second injector had changeable and not perfect spary pattern. but after 10-15 minutes of polishing paste spray pattern became almost perfect. mechanic said that there is no way this injector could be causing problem like yours..... after assembly car run just the same ??? no changes at all.
internal pressure is good, timing is set to 0.95-1,00 milimeters. it pulls just fine..... the only problematic thing left in transmission is the dif. yes it has whining noise but could it be causing the issue....
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If it will do it in neutral everything in the trans and transfer case is not relevant.
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I disagree, maybe not the diff..
But in neutral with clutch out the trans is still turning shafts and such.
Have you tried with the cl7tch in and the car not moving??
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i've spent more than 600-700 $ on this engine and pump rebuild already (+ 600 $ for the engine itself :D). a'm already thinking of leaving it alone ;D only option left (that will probably not change anything) is to increase internal pressure.
another question that i have: can bad hydrolifters cause this? i have knocking lifters that seem to be worn, but can they cause things like this ? :-\
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a little update, today i had my injectors tested... all of them were at 145 :-\ only second injector had changeable and not perfect spary pattern. but after 10-15 minutes of polishing paste spray pattern became almost perfect. mechanic said that there is no way this injector could be causing problem like yours..... after assembly car run just the same ??? no changes at all.
internal pressure is good, timing is set to 0.95-1,00 milimeters. it pulls just fine..... the only problematic thing left in transmission is the dif. yes it has whining noise but could it be causing the issue....
Has your mechanic actually witnessed your problem and concurred, or is he just going by your description?
Let's take this a step further... Do you have a camera that you can do a sound recording with?
If so can you place it about 4ft in front of the car [hood down] and record the engine at idle and then up to shudder point and just the other side. Link us to it and I'll see if anything shows up on that spectrum thingy of mine... :)
Do a video of the same but with hood up and looking at the engine...
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sorry for my late reply, after injector check i had injector leaking problem and after resurfacing the mating surfaces of nozzle and other injector parts wit fine sandpaper leaking problems went away :)
but twitching problem is still there. i even notice taht car doesn't run well on idle. it doesent misfire but i can feel that engine does not run evenly. even though at 5' celsius car starts without cold start lever and glowplugs after 2 hour rest... i will also check camshaft and IP timing in near future.
added a bit of interal pressure to the pump (so that "marble noise" is heared just a little bit in middle range). a am also planning on making internal pressure gauge to set the pressure as it is intended to be :)
in few days i will post audio files as MARK Uk told me.
i also have one more question, can bad hydro lifters be causing this issue? i have noisy lifters but never heard taht bad lifters may be causing twitching or other problems in diesel engines.... :|
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Bad lifters can cause misfires, particularly at increased rpm, IMO.
If they are going to be replaced, I'd do that first and see if the misfire resolves. If it does not resolve, no big loss and one less job to finish.
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i disassambled and checked the fuel pump for faults, everything is just the way i left it there 1 year ago :D
only lifters are left to be excluded. interesting thing is that bucking gets worse when oil pressure drops after heating up the oil and lifters start to click....
now i'm running shell helis hx5 10-40 for alreadu 2500 kilometers, i do not have oil cooler but after calm city driving for about 7-8 kilometers pressure at idle drops down to 0.4 bar. at 3000 revs it gets up to 2.0 bars. after driving hard it gets even worse and lifter clacking gets louder 9so does the bucking, get more apparent)...
i think that i has something to do with the oil. when i had castrol edge 10-60, before the engine rebuild even after driving up hill the pressure used to stay minimum at 0.8 bar and there was no bucking at mid revs
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If oil pressure is erratic, oil pump or IM-shaft bearings are suspect.
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im shaft front bearing was replaced, and slightly used one was installed instead of the original that had some play. rear bearing was good, without scoring and signs of abnormal use.
i will change the oil soon (going to use motul 6100 10-40 or 15-50).
another problem that i have now is the oil light, it goes out only after 3.5 seconds after i start the engine in the morning. i think that it might be faulty drainback valve in the oil filter. i will install mahle oil fiter when i change the oil
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Yeah, get a good filter on it and try a 15w-40 oil if you can. Sounds like could be your filter or something of a tired engine.
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(http://vardzelashvili.com/imghost/images/90000IMG_20140408_191719.jpg) (http://vardzelashvili.com/imghost/view.php?filename=90000IMG_20140408_191719.jpg)(http://vardzelashvili.com/imghost/images/51097IMG_20140408_191729.jpg) (http://vardzelashvili.com/imghost/view.php?filename=51097IMG_20140408_191729.jpg)(http://vardzelashvili.com/imghost/images/45971IMG_20140408_191734.jpg) (http://vardzelashvili.com/imghost/view.php?filename=45971IMG_20140408_191734.jpg)(http://vardzelashvili.com/imghost/images/86815IMG_20140408_191826.jpg) (http://vardzelashvili.com/imghost/view.php?filename=86815IMG_20140408_191826.jpg)(http://vardzelashvili.com/imghost/images/37369IMG_20140408_191837.jpg) (http://vardzelashvili.com/imghost/view.php?filename=37369IMG_20140408_191837.jpg)
;D ::) mahle oil filter, made in austria. price 7.5$
i will probably change oil tomorrow
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chamged the oil few days ago, eneos super plus diesel 20w-50. with new oil and filter oil presure light goes off 1.6 seconds after the car starts in the morning, and after 0.5 seconds when the engine is warm.
pressure is also quite right, 0.8 bar after calm city driving on idle, and 0.5 after heavy throttle driving in the city. also engine runs quieter due to high oil pressure. and lifter tick only lightly...
still after warming up engine starts to buck at ~2000. i have driven many cars with sever lifter problems, but still non of them had the symptons that my car has. despite the fact that i have checked everything in the pump i still think of getting a new one :( it's really annoying during low rpm city driving
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Audio track of engine, or video track of exhaust if anything is happening there @ and either side of 2000 rpm HOOD DOWN...
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Audio track of engine, or video track of exhaust if anything is happening there @ and either side of 2000 rpm HOOD DOWN...
I will record the sound in near future and post the video here. I eill have to have a ride at night, when there is no traffic sounds and streets are free for experiments :D
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I was not able to record the sound of an engine but i've got several news. yesterday i drove my friends peugeot 306 1.9td, that had 1 broken engine mount and when i took off the foot of the accelerator and than push it again it used to buck for some time, until engine has more power and after that it drove normally. my car behaves the same, way, when i accelerate hard there is no bucking at all, but under light throttle it twitches on mid revs... it might even be engine mounts, but still don't know :D
after peugeot test drive i measured boost pressure on my engine, inspite of the fact that my suzuki vitara, on 31' tires drove almost better than stock peugeot (running 0.9 bar above 2500rpm), it turned out that i almost do not have boost pressure... gauge hardly moved above 0.4 bar. it seems that i do not have any major boost leak, there is black smoke under acclereation (mixture is not lean), wastegate rod is extenden up to the limit.... but still i do not get boost ??? strange :o
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wastegate rod is extenden up to the limit.... but still i do not get boost ??? strange :o
Not sure if I understand clearly but the rod to the wastegate must hold it shut until it reaches your set boost level.
Don't know about your set-up but most boost pots extend the rod to open the gate. It should be closed tightly at idle and under some considerable spring pressure.