1.9 GTi idling-problem!

[Lunatic 0]

Hi folks,

 

I got a problem with the idling of a 1.9 GTI. When I start the car up it idles fine (a little over 1000rpm) for about 2-3 seconds. But then the rpm suddenly drop at about 500-600rpm. When I give a little bit of throttle to hold it at about 1000-1200rpm the engine still doesnt sound "good/fine" (I think it pops a little bit aswell). At 2000rpm everything sounds fine.

 

The GTi has a slightly hotter cam and I checked the valves. At least one intake-valve is at 0.4 instead of 0.2! Could this be the reason, or is there a bigger problem?

 

btw: what is the idling-rpm when the engine is cold or hot?

 

Thanks a lot

[Thijs_Rallye 86 4 Cars]

If one intake valve is at 0,4 mm it really needs adjusting. It could be many things, but an engine code is necessary to know what I'm dealing with ;).

 

Popping / not running right sounds like a mis-adjusted ignition or an air leak.

[Lunatic 0]

It is a 120hp XU9JAZ (DKZ) engine.

 

Is it possible that my mate got the wrong timing belt or that the belt was fittet wrong (by one tooth)? Or could it be that this one valve is causing that lots of trouble?

 

I know, that the car ran fine before installing the other cam/timing belt... I would even say the idling was very high before. But after he changed the parts it is running bad. Also the throttle response from low revs is quite bad. I have not that big experience in 205 GTis (only 106 GTIs) so maybe there is a common problem...

 

sorry for my bad english, I hope you can understand everything.

 

Edited June 5, 2018 by Lunatic

[Thijs_Rallye 86 4 Cars]

If it was running fine before the belt change my bet would be you'd have to look there. Idling is a purely mechanical deal on the 8v, no stepper motors or anything, just an air bypass screw on the throttle body and a supplemental air device for the initial start up idle.

 

What I'd do first is remove the top cam belt cover and time the engine and see you can fit the locking dowels. Continue searching from there on. The loose valve isn't causing this but is something you should address imho.

 

[Lunatic 0]

Thanks a lot mate!

 

Can you tell me what the idle should be cold/hot? And where is the revlimiter?

[Thijs_Rallye 86 4 Cars]

Idle (standard engine) should be around 1000 +/- 50 RPM hot. So it could be necessary to set it a bit higher because of the hotter cam. Mine runs around 1100 RPM hot, no load on alternator with a Catcams 4900365.

 

Please let us know your findings.

[Telf 222 2 Cars]

did u fit the cam belt correctly? I had mine slip by 2 teeth after an installation - it ran like crap - popped and banged and blew up 2 rear silencers as unburnt fuel was getting into the silencer- the car would drive though- I'd check your belt alignment if its just been changed

 

[Lunatic 0]

I didn't fit the belt in the first time :P

 

Checked it yesterday and saw that the belt wasn't installed correctly. Was installed/slipped by 1 tooth. The so called "mechanic" caused a lot of trouble as he didn't install the timing belt, brake lines and airfilter correctly. Apart from that the totally failed in checking the valve clearence. I hope the engine took no damage (and the catalytic converter) because of the belt???? We didn't revved it up much as we saw that is war running like a piece of garbage.

 

We installed the belt correctly and now the engine seems to run smooth, but now we got another problem. The timing belt is slipping of the gearwheel of the camshaft. We hat no time to solve the problem as it was dark when we finished to solve the first problem.

[Thijs_Rallye 86 4 Cars]

I think you may have the wrong belt fitted. You probably need the 113 tooth belt and my guess is you have the 114 tooth belt fitted.

Have you seen your tensioner? Was it a roll or was it one with a metal back plate and spring loaded?

[Lunatic 0]

Thanks for your help. I'm pretty sure it is the right belt, because otherwise the timing of the engine would have been so terrible (after a few seconds of running) that the valves would have "kissed" the pistons. Or am I wrong?

[Richie-Van-GTi 70 2 Cars]

Wrong, number of teeth won't directly effect timing in the sense of running as the 2.1 ratio isn't changed. However the way the belt fits the system overall is compromised so shouldn't be overlooked. The give away is the type of tensioner used.

[Richie-Van-GTi 70 2 Cars]

Problem you may have is any slight change in cam timing will directly affect fuel and spark timing as the dizzy is moved with cam. Maybe worth throwing a strobe on it to verify what angle it's idling at

[Anthony 1,000]

4 minutes ago, Richie-Van-GTi said:

Problem you may have is any slight change in cam timing will directly affect fuel and spark timing as the dizzy is moved with cam. Maybe worth throwing a strobe on it to verify what angle it's idling at

Given it's a DKZ, assuming that it's running the original Motronic 1.3 management it'll make no difference to spark/injection as timing is via the flywheel.  Cam timing could still be out of course.

[Richie-Van-GTi 70 2 Cars]

49 minutes ago, Anthony said:

Given it's a DKZ, assuming that it's running the original Motronic 1.3 management it'll make no difference to spark/injection as timing is via the flywheel.  Cam timing could still be out of course.

Well spotted, I stand corrected. Ta

[Lunatic 0]

tensioner looks exactly the same as the old one, so I think the belt is the correct one. Gotta sort out the problem this evening. I let you know ;)

[Lunatic 0]

Is there maybe any kind of standard procedure to seit the correct idle for the 205 GTi 1.9 with 120hp? I got one with a slighty hotter cam and the idling is awful. Cold start is at 1700rpm, then it runs on 1200 and after a few mins it drops to like 650/700. Also when the idle is at 1200 there are sometimes “pop“-sounds. Car hasn't been started for a few years... I changed the plugs, timing belt, oil and fuel.

[Thijs_Rallye 86 4 Cars]

I usually set them at 950/1000 RPM, engine hot with the lights on fan off.

 

There are a few things to check: check if the TPS is working as it should with a multi meter, check if the SAD is operational and last but not least, be 100% sure that there are no air leaks.

 

 

[estland 3]

Could be the Air flow meter. It mostly wears at the idle position. Remove the cover and check for white wear marks (you can use a multimeter to test the signal also). As a temporary fix you can gently put pencil graphite on the worn part.

Edited June 19, 2018 by estland

[Lunatic 0]

Here are 2 videos:

 

https://streamable.com/mc7nr

 

https://streamable.com/uc1g1

 

 

In one video you can see, that, if i give a little bit throttle it "struggles" to get back to idling. (I just tap on the gas pedal and then leave it)

In the other video you can hear "popping sounds" when idling... 

 

Does this help?

Edited July 1, 2018 by Lunatic

[Thijs_Rallye 86 4 Cars]

Have you checked the operation of the TPS switches yet?