306 Gti6 Running Woes

[Edp 67 3 Cars]

Hey,

 

Little problem which is starting to make me pull my hair out and hurt my bank balance. My Sorrento GTi6 is idling like a bag of s*ite. It idles lumpy, is really jerky to drive at low revs and is running really rich. This all happens after a superb drive in the car just a week ago where I took it out for a good long run and it performed as it should.

 

The car still drives fine at high revs and goes superbly but its just when you drop the revs and have to pull out of a junction and the thing is very jerky. It has stalled a couple of times too.

 

So after a fair search on here and the 306 forum I thought the first port of call was the stepper motor or ICV (idle control valve) I removed the old one gave it a good clean, put it back and still the same. So I replaced it. Still the same. I then preceded to change the

 

*map sensor

*ECU temp sender

*ICV (AGAIN)

*throttle position sensor

*plugs

 

Each time doing a ECU reset.

 

The only sensor left to change is the Lambda but that is brand new and when I unplug it the car slowly drops in revs and eventually dies. I'm now starting to think the ECU is f***ed. Anyone offer me any good advice? I need a beer.

 

By the way if you remove the little hose which attaches to the fuel pressure regulator are you meant to feel it sucking in air? My one dosent.. .. ..

 

Cheers

Edited October 9, 2009 by Edp

[dcc 855]

there is a blue cam sensor, don't know how much this would alter your idle though. when i forgot to plug mine back in, sometimes it wouldnt start first time, and made the fuel consumption go to roughly 5-10mpg.

[Edp 67 3 Cars]

Ok so its not the ECU. Borrowed Mattgti's 306 this morning and tested my ECU. His car ran fine. More frustration as I didnt unplug the ECU while the car was running and now It is immobilised!

 

 

Getting f***ed off with it. Losing my patience and might break it for parts....

Edited October 11, 2009 by Edp

[DrSarty 90 1 Cars]

Losing my patience and might break it for parts....

 

 

How very dare you!

 

EDIT: Is there some crud in a hose somewhere? You mentioned the FPR vacuum hose; pull it off (fnarr) and blow through it and try the same on the ICV and breather hoses.

 

Do you have the purge canister connected up? Could that be pissing you about?

 

Throttle butterfly naffed? Something inside the air filter?

 

Sorry: just trying to throw some ideas at you as I bet it's something simple.

Edited October 11, 2009 by DrSarty

[Galifrey 1]

More frustration as I didnt unplug the ECU while the car was running and now It is immobilised!

 

 

Getting f***ed off with it. Losing my patience and might break it for parts....

 

Plug it back into matts, ignition on, input code (if applicable) and remove ecu, will be unlocked again.

 

At least you have access to the car that locked it.

[Edp 67 3 Cars]

Plug it back into matts, ignition on, input code (if applicable) and remove ecu, will be unlocked again.

 

At least you have access to the car that locked it.

 

 

I haven't got the code/key for that ECU I bought it from someone on here ages ago and worked fine to start with until I started having these idle problems. I thought it might be an ECU issue so borrowed Matts standard car to check it then didn't think to unplug it while it was running, what a plum!

Edited October 11, 2009 by Edp

[welshpug 1,621]

that will only work if Edps transponder is used AFAIK

 

DOH!

Edited October 11, 2009 by welshpug

[Edp 67 3 Cars]

that will only work if dan's transponder is used AFAIK

 

DOH!

 

 

Whos Dan?

 

Your right about the transponder though!

[Galifrey 1]

that will only work if Edps transponder is used AFAIK

 

DOH!

 

Oh, right, thought it needed the key/code from the car that locked it, not the key/code from the original ecu... That is a big DOH! then

[taylorspug 7]

Ed, do you want me to pop over and take a look?

[Edp 67 3 Cars]

 

How very dare you!

 

EDIT: Is there some crud in a hose somewhere? You mentioned the FPR vacuum hose; pull it off (fnarr) and blow through it and try the same on the ICV and breather hoses.

 

Do you have the purge canister connected up? Could that be pissing you about?

 

Throttle butterfly naffed? Something inside the air filter?

 

Sorry: just trying to throw some ideas at you as I bet it's something simple.

 

Tried all of the above. No purge canister either to cause trouble. The car drives fine when out on the open road so the butterfly is ok. I'm 99% sure its electrical.

 

 

Ed, do you want me to pop over and take a look?

 

Dan that would be superb. Although would it be better to bring it to you? once I've got a working ECU

[Edp 67 3 Cars]

Update time,

 

Bad news first, the ECU I had working before we put it in Matts car is definitely locked so that is going on the shelf to get dusty.

 

Good news, the car is no longer being broken for spares. When I bought the 306 engine I was in Thailand and I bought it from a spares place in Gateshead Newcastle. The engine hadn't been removed from the car so I asked them for both the transponder box and the chip from the key.

 

They obliged so I had a locked ECU but all the parts to unlock it if I had a standard 306. In walks Matt with his red 306. After carefully stripping the hand-brake surround and lower dash part we unearthed the transponder in its little cubby hole. A quick swap for mine and the chip and ECU in there place I held my breath as he turned the key. It only worked. Finally some good news. So after a day of throwing my toys out the pram I now have what I started the day with, a 205 with a unlocked ECU running lumpy. Still it could be worse I guess.

 

So the question is why is the car running crap. I'm now not so sure its electrical. Its running rich and lumpy and although when at full chat its goes fantastic when pulling up to various junctions on a quick thrash home from Matts it stalls too.

 

I've now worked out its not:

 

*map sensor

*ECU temp sender

*ICV (AGAIN)

*throttle position sensor

*plugs

*ECU (after hassle)

 

Lambda anyone?

[taylorspug 7]

I dont mind coming over armed with a multimeter to bell a few things through and rule some stuff out. From what ive seen they usually run fine without the lambda plugged in, i hada GTI6 engined 205 in the workshop a few months ago with no lambda sensor, ran much the same once i fitted one.

[welshpug 1,621]

The stalling when going onto idle might well be the VSS.

 

you said there was no vacuum on the pipe to the fuel pressure regulator, it is a small hole, but you should still feel something, without that it'd be running quite rich with the throttle closed as its meant to back off to 2.2bar from 3 IIRC.

 

is it actually misfiring or just running a bit rough?

[Edp 67 3 Cars]

I dont mind coming over armed with a multimeter to bell a few things through and rule some stuff out. From what ive seen they usually run fine without the lambda plugged in, i hada GTI6 engined 205 in the workshop a few months ago with no lambda sensor, ran much the same once i fitted one.

 

 

It would be great if you could give it the once over. Is definitely dies when there is no Lambda plugged in. I even unplugged it and did a ECU reset but it was still the same. I've ordered a decent Bosch Lambda as the one I put on when doing the conversion was a cheap option, although it was brand new. Maybe it is f***ed as looking at the 306 forum there are lots of problems with cheap Lambdas.

 

 

The stalling when going onto idle might well be the VSS.

 

you said there was no vacuum on the pipe to the fuel pressure regulator, it is a small hole, but you should still feel something, without that it'd be running quite rich with the throttle closed as its meant to back off to 2.2bar from 3 IIRC.

 

is it actually misfiring or just running a bit rough?

 

 

There is vacuum from the inlet end. I don't think it s regulator problem.

 

The car idles rough and when driving it is a bit chuggy. When sitting at a junction you pull away and it feels like you are towing someone then once it gets to about 2k it takes off and its fine. It has only stalled a couple of times but then it never did this when I got the car on the road to begin with.

 

'Tis a strange one

[Edp 67 3 Cars]

Quick update,

 

Now replaced all the above plus,

 

*Coil packs

*New bosch Lambda

 

The car does start better but it still idles rough. The tone from the exhaust sounds like the engine is redlining, bouncing off the limiter it is very strange. Also when in 4th and driving down a hill it kangaroos real bad! I also had a problem when coming up to junctions after a normal drive the engine would idle at 2k. Until I dip the clutch and it would return to 1k. I seemed to have solved this by swapping the throttle position sensor over again.

 

Anything else I can try to sort the idle/kangarooing?

[Galifrey 1]

Have you tried replacing/checking the fuel pressure reg as mentioned earlier?

 

When you lift off the throttle the reg opens and returns fuel to the fuel tank, if this isnt happening is there a chance it is overfueling and filthing up the plugs/messing with the lambda reading?

[Edp 67 3 Cars]

Haven't changed that yet. Maybe thats why it starts ok but after a few seconds it starts to overfuel?

 

Need to find one of those now

[gti-si 0]

When sitting at a junction you pull away and it feels like you are towing someone then once it gets to about 2k it takes off and its fine

 

Don't think this will be the whole issue, but, that definitely sounds like an absent/f***ed VSS. Have you got an s16 speedo drive with the cable and electronic output? I've not got the electronic output on mine and it is quite a hesitant little bastard up until about 2k. Replacing this may sort that out. As for the idle though, that shouldn't be effected by it.

[Batfink 201]

Dan was offering to help look at the car....might be worth giving him a call really...

[Edp 67 3 Cars]

Dan was offering to help look at the car....might be worth giving him a call really...

 

 

Thanks for jogging my memory Batboy, unfortunately we are both busy fellas and its hard to make time to meet up

 

Anyway, I 'think' I've sorted it. Was chatting to a bloke at work and he suggested checking the cam timing. He once had an old Ford which slipped and tooth and sounded similar to my idle problems. So in the dark earlier I removed the cam belt cover and lower arch cover, put the 6mm dowel in the inlet cam and the 8mm crank sprocket and low and behold..... the exhaust cam had definitely moved round by about the size of the 6mm dowel?! So removed the belt and put it all back together, turned it over by hand 3 times and checked the dowels all fitted, which they did!

 

Turned the key and it idles perfectly. Slight whine from the cambelt so I need to take it all back off again as I think I've over tightened it. But it looks like this little saga is at an end (hopefully). Cheers for all the informative posts trying to help, much appreciated!

[camgti 56]

Sorry for the thread revival!

 

But, Ive just completed a 6 comversion ( VTS Actually ) and mine has the exact symptoms. Idle is not the best, will stall sometimes ( slowly dying ) and once over about 2-2.5k revs is fine.

 

I was hoping it was going to be the ICV but after reading your story Im not so sure. Was it the timing of it in the end?

 

Cam