GolfGTIforum.co.uk
Model specific boards => Golf mk2 => Topic started by: speedy gonzales on 04 October 2005, 15:45
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People,
When I start my gti (8v) it revs to 2000 and then drops right down as if its gonna stall, then it picks up again to 2000 and it continues to do that until i get bored and turn the engine off and go inside for a cuppa tea!
The blue temp sender may be at fault as when I push down on the connector wire it starts to rev a bit higher.
Would you suggest changing the sender or change the connector lead
Thanks guys, oh and wrap up this winter's gonna be a b!tch'n!!!!
Speedy G
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might be wanting to check your idle stabilisation valve aswell, or rather give it a clean, its generally these that cause most idle problems.
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i had a vr6 that did this, i spent a fortune on new sensors, idle control valves, coil packs and everything else people recomended, VW's computer found nothing wrong aswell. turned out in the end to be damaged/burnt piston rings?!
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change or fix the connections on the blue temp sensor.
look for air leaks. cleaning the ISV is a waste of time. Look for damaged vacum hoses and check the rubber bung ontop of the rocker cover. The bung seals the oil breather to the rocker cover. yours might be split which is common
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Check the idle switch clicks when the throttle is closed. On the MK2 8v its underneath the throttle body, you have to take off the inlet boot to get to it. Plus the screws are almost impossible to get to unless you remove the throttle body, so I tapped mine with a hammer till it move enough to click when the throttle is closed. No more hunting idle for me :)
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i had this problem on my mk2 8v thought it was isv valve but it was'nt found out they was some broken wires at the rear of the engine behind the accelerator bits so i plugged them in n it stopped
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Check the idle switch clicks when the throttle is closed. On the MK2 8v its underneath the throttle body, you have to take off the inlet boot to get to it. Plus the screws are almost impossible to get to unless you remove the throttle body, so I tapped mine with a hammer till it move enough to click when the throttle is closed. No more hunting idle for me :)
They can still be faulty even if you hear the switch go click. On mine the actual contactors in the switch are working intermitantly, sometomes the idle is fine , other times it is too high (isv not kicking in). A blip of throttle is needed to persuade the switch to work.
Not been bothered to fix it yet, cox as you say need to remove throttle body.
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Thanks guys,
Does the above fit in with the fact that when i rev the engine, the revs come back down slowly!! I have been running in circles in looking for an air leak (but cant find any), ive changed the rocker cover, the gasket and the rubber grommet that lies on top of the rocker cover.
I have now ordered the blue temp sender and connector wire (so i can work over it on the w/end). Does anyone know of any person i can go to to get this sorted (any one in Essex) if i dont manage to fix it?
Appreciate the help guys
Speedy G
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Does the above fit in with the fact that when i rev the engine, the revs come back down slowly!!ÂÂÂ
Yes. Mine does this also when the switch is not working.
:sad:
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I've been chasing a problem like that for ages. Blue temp. sensor changed fixed my revving problem but it still stalls on occasion. If you track down your problem let me know.......please!!!!
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If it stalls or cuts out then maybe you need to check the coil pack and leads?
Speedy G
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Mines used to do that too, although it's a 16V it was just the mixture needed setting right - have you checked yours?
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Guys, i know its been some time but i have been mega busy (as a doctor you know....saving peoples lives and SH!T)
had a brief look under the bonnet with regards to the idleing problem and realised that if i disconnect the blue temp sender lead, the car revs perfectly at 100rpms! Does that mean that i have finally found the problem? Shall i order a new temp sender and stick it on?
Remember, my car was fine before i decided to change the R-Cover Gasket, and when i put it all together, there was one problem after another. I also found that the rubber bung (on top of the rocker cover) was also broken (split) again!!!
What's your opinion? Blue temp sender at fault?
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If it makes a diff then it suggests the sender is working, you might have to set up the base idle & CO again. Its worth replacing anyway as its cheap :)
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Well worth changing the temp sensor and relatively cheap too. You can test it:-
http://volkswagen.msk.ru/vw_doc/eva2/FU01/ch7.2.1.html
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If that doesn't fix it it is well worth cleaning the ISV and checking the throttle body switches as previously mentioned:-
http://volkswagen.msk.ru/vw_doc/eva2/FU01/ch7.3.2.html
http://www.20v.org/engprob.htm#isv
http://volkswagen.msk.ru/vw_doc/eva2/FU01/ch7.3.3.html
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And reset the base idle & CO:
http://volkswagen.msk.ru/vw_doc/eva2/FU01/ch7.6.html
Especially if you have fixed an air leak :)
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Believe or not, I've recently changed my Rocker cover gasket and she's running like a dog!! Doesn't want to idle after startup and occasionally but not always, have random revs - up to 2 or 3000! Pain in the arse!
I think that it would be a good idea to clean the ISV etc, but a quick check of this blue temp sender may cure my blues!!! :grin:
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sounds like you've cured an air leak so need to reset the CO & idle as above. Do the blue temp sender 1st & check any wiring around that area you might have disturbed, and that the oil filler cap is on properly (yes I've done this before!)
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Guys, I really appreciate your help (esp the web links!).
Will get under the bonnet on saturday and report back what I found.
Thanks again.
Speedy
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I have had this problem as well.
This is what I have done and the car is running a lot better, still stalls sometimes but nothing like it was.
Had the fuel mixture reset(it was running 3 times as rich as it should of been)
Replaced spark plugs and leads
Checked all inlet hoses, breather hoses and inlet manifold for leaks.
Cleaned all breather hoses
Cleaned inlet manifold with Forte air intake cleaner.
I am going to change the fuel filter aswell :smiley:
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idle/ignition advance or timing may need a slight adjustment.
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Right as i've said i've had the rocker cover gasket changed recently and the car has been running badly ever since. I looked at it yesterday and the round flying saucer thing on top of the rocker cover is split where it attaches to the rocker cover.
What is this thing called and is it just a case of getting a new seal or something?
When I press on it the engine seems to idle better.
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That'll be your problem, 'PCV valve bung' is what it is normally called. Can get em cheap from ebay/GSF :)
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Ok...After sloggin away under the bonnet, here is the lastest!
I bought a new temp sender, put it in and ALAS.. :cry:....nothing! the idle problem is still there. it revs to 2000rpm and then drops to 500rpm (about to stall) before the revs pick up again and ..so the cycle continues.
HOWEVER, if i push in the ISV in all the way I found that the CAR RUNS PERFECTLY (exactly on 1000rpm idle) and when i accelerate the revs come down as they should and not slowly as if i still have my foot on the throttle.
Do you think my ISV is knackerd. I know some of you guys said that this can be a cause of this problem but what shall i do, shall i order a new one or somehow clean it.
also is is safe for me to drive around with a cable-tier holding the ISV all the way in? Can this be attributed to a faulty ISV or am i just superficially sorting the problem without actually getting to the main cause of the problem?
Im not to hot about these engine parts so i may sound like a wolly if i have asked ridiculous questions. :undecided:
faulty ISV or not??
Speedy (not so speedy at the mo!) :cry:
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Well replace the rubber bung for the PCV first (the flying saucer thing) The ISV has2 hoses going to it, both should be held on with jubilee clips, if one or both are missing then you wont be getting a good airtight seal, so best you get them replaced ASAP :)
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That vacuum hose to throttle valve, is that important as I have lost mine?
I had a KN induction kit on for a while, but I decided to take it off and put the original air box back on a couple of weeks ago and the vacuum hose is err missing?
The car wouldn't stall without this on would it?
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aye it might, thats a hefty air leak!
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Thnaks RubJonny!!
Changed the PCV bung earlier and she started sweet as a nut!Idling smooth as too! First time in ages, so it appears that the problem is solved. I'll keep you posted as i'm taking her for a spin later. Hopefully no more revving and stalling!
Ta.
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:smiley:
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I had this problem on my 8v. It was "hunting", going from 500rpm to 900rpm and back again, all the time, while idling. I've now sorted it by following these instructions:
1. ignition off
2. disconnect breather hose from pressure valve (big round thing) on rocker cover
3. plug breather hose with something
4. start engine
5. allow to idle for 1 minute
6. disconnect engine collant sensor multi plug (rear sensor on housing at front of cyl head, as in pic)
(http://img.photobucket.com/albums/v286/whereismy/mk2/wooooo006Small.jpg)
IF engine cuts out then reconnect the multiplug before restarting.
7. increase engine speed 3 three times to over 3000 rpm
8. allow to idle
9. adjust co if ness