GolfGTIforum.co.uk
Model specific boards => Golf mk3 => Topic started by: deanpompey on 24 February 2010, 18:59
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ok so took my donor out of a 95 8v gti. ady code. ran beautifully, didnt miss a beat or splutter.
put it into a mk2 5days later and now it misfires like a b!tch an splutters like hell when you put your foot down. also wont idle correctly, sometimes just far too high, sometimes too low, others will hunt like a b!tch.
timing has not been touched.
ecu etc all from same car.
new plugs, leads,cap,rotor arm.
tried 4 ecu relays all from working vehicles.
compression results: 120 130 120 120 psi respectively
no apparent air leaks.
no vagcom fault codes.
Garage's scanners wont give real time data (could this be cos diag port is wired to ign live instead of perm live?)
very friggin confused!
any ideas people?
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oh and TB clean as a whistle
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Maybe the coil pack?!
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sounds like electrical / sensor issue. What did you do with temperature sensors (oil, water), pressure (oil), air flow, air temp and o2 sensors? Also worth checking that the throttle position sensor is wired ok.
Also need to investigate why the diagnostic port doesn't work. Get vag-com on it too.
J
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got vagcom on it today just had a blast at measuring blocks as was only there for 5mins
throttle angle is sitting at 10.00 degrees, should be between 2.5 and 6.5
throttle regl should be 6 - 21% mine is around 38% and varies
intake air temp 15-55 deg, mine is 149?! doesnt change at all, but then i dont have the switch in atm as the induction kit i have on it is for vr, switch is currently sat in the cold air feed hiole in wing, so shouldnt be that high? need to get it incorporated somehow.. but pretty sure sensor is dead anyway with reading being that high.
group 1 box 3 02 sensor should be between 0.0 1.1 mine is 1.56 aand adjust conditions should be 00000000 mine is 10000011 dead lambda?? brand new fitted 2 days ago, although wire could have been broken as it was fitted dodgily.
reckon these are my problems then?
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those comp test figures looks pretty low....
I had 160 on 3 cylinders and 150 on 1.
Does sound electrical though dude, try a new coil.
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it was a basic hand held gauge, engine turned 3 times only. if id have cranked it 5 times it would have been 150's and 160's.
and going off the vagcom readings i dont think its the coil, more like sensor issues
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iv just read a REALLY old thread found in the deepest darkest depths of google, says that you can get an 8v to re align the throttle itself by simply turning ignition on and leaving it for 5mins and car will realign itself? does that actually work??
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I have done the same mate, after battery disconnection it makes a reset of sensor readings as far as I know. Lots of clicking and whirring - when stopped, start the car and drive (if it works lol)
You can do a TB alignment from vagcom as well. I would perform an ECU reset and TB align, then see if any readings are still way out...
Im feeling that the IAT reading at 149 may be the cause, or the MAF is reading nonsense, mine started acting up tonight in a similar way but after switch off and restart, it was ok....weird. I'm suspecting the MAF on mine, not sure yet if the VR has an IAT too as only had gti's before.
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ok so i had 5 or 6 fault codes on vagcom this morning, and TB alignment was doing nothing. cleared the codes, now only one coming back is hall sensor. which is strange seeing as its come up with 2 known working dizzy's?
then after all the days of swapping bits over and messing around, i decided to try the leads anyways... put my mates leads on, and BINGO! runs lovely, well, until it hits the 5000rpm limiter :(
can anyone provide me with a list of things that could cause this?
i know timing is one, and i think crank timing is out a tooth, so thinking that could be my problem, but just want to check any other options first as i dont particularly want to do a cam belt change, and i dont wanna pay a garage to do it either! it is running fine apart from the limiter, so it will serve the purpose of getting it through the MOT retest.
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well the hall sensor is one possibility and if it shows up on VAGCOM then I'd put my money on that.
Was it me that said leads to you the other day when you called me??
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yeah mate. But then plugs/leads/cap/rotor is first port of call for misfire, and as they had all been replaced brand new in last 2 weeks, they got dis counted.
ah well, least its sorted!
As for hall sender, i just dont see it, 2 known working Dizzys, both coming up with hall sender faults?? im thinking possibly the wiring as opposed to the hall sender? fault it registers is signal outside of specifications....
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had a gti 8v ady motor with the timing belt 1 tooth out, ran fine but wouldnt pass 5k rpm.
dizzy didnt cure it as I first tried that, then realised the guy i bought it from had done the tb himself, so on checking it, found it was 1 tooth advanced. I think this causes the hall sensor error - implausible signal - as the cam is out of position as far as the HES is concerned.
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yeah thats along lines of what i was thinking :)
cam mark lines up, dizzy lines up, crank/intermediate dont.
will get it MOT'd and then do belt next weekend or something.
my skinny wheels cant take the torque anyways so 5k rpm is plenty at mo :lol:
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I'm pretty sure there is a punched dot on the INSIDE of the pulley, it is in a different location to the one on the OUTSIDE of the pulley. I remember when I had the mk2 it had this and it ran but not perfectly due to the fact it was timed up to the dot on the outside, and not the one on the inside (Should be the inside one).
Have a look.
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>crank/intermediate dont.
what are you using to see the crank alignment. The mark on the pully is rubbish - use the flywheel mark - much better. Also not sure the intermediate matters, as long as the dizzy is correctly set.
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yeah was looking at the mark on the pulley. will check at flywheel once i got a ticket on her :)