My G60's Lumpy as hell...please help!

[TomD 0]

Hi All!

 

Before I start...I've searched loads on this topic, there seem to be lots of similar problems, but no one quite seems to have the same problem or have solved their problems with bits I've already changed.

 

Basically sometimes it'll idle terribly, as you come off the throttle the needle drops right down, almost cuts out but doesnt, then sits well below 1k and fluctuates alot (more than it should!), meanwhile the car shakes and it sounds like its misfiring.

 

Also, when you're moving, when the revs are around 1k to 3k ish, the car jumps, again like its misfiring. But only when you're really lightly on the throttle. Nail it and its smooth as anything, but just a tiny bit and it feels terrible.

 

For example sometimes I have to drive round town in 2nd/3rd as it can't hack it in 4th/5th.

 

When I bought the car I fitted new bosch plugs, new GSF leads, a new rotor arm and dizzy cap. Also bought it a brand new manifold to ECU pipe which is exactly 1m

 

Initally I though it was a dud lead, so bought a another set of leads from GSF but no change.

 

Also when you're on a long run sittting at 80 (ish) on the motorway its fine, but then when say you come to a roundabout and have to stop and put the clutch down the idle is awful again.

 

Timing seems fine and if it wasn't I would have thought it would cause the problem all the time, not on and off.

 

I've replaced the Fuel filter and its nearly always run on BP ultimate (seems to run a lot smoother on that!) or V power or other Super Unleaded, and I often has injector cleaner run through it.

 

The fact that its kind of intermittent makes me thinks its vaguely electrical (Could well be to do with temp as it seems to idle fine when I fire it up in the morning, and seems to only do it when the engine's warm)

 

But I'm 99% sure its not the HT Leads/Dizzy/Rotor Arm/Plugs etc.

 

So...

 

1) Is there a microswitch on the throttle body like the mk2 golf digi's?

 

2) I'm thinking it could possibly be the blue coolant temp sender if it is connected to engine temp.

 

3) Could it also be the Lamda Sensor? I don't know much about these as my old golf didn't have one! Does the ECU ignore any info sent from this until its warm? That would tie in with engine temp.

 

4) When I went to GSF they told me they had 2 dizzy cap's listed for the G60...does it make a big difference if I bought the wrong one, and how can I tell if I've got the right one?

 

5) ISV? Think its fine but are they as dodgy on these as 8v's? Agian...can't see why that would be intermittent.

 

Please help, its not a happy bunny at the moment!

 

If I need to cross more things off the list...whats the best to do next, coolant temp sensor I guess? Lambda maybe??

 

Cheers,

Tom

[TomD 0]

Also, could the CO pot cause it? :)

[VEEDUBBED 0]

Dizzy caps are all the same,8v,16v etc.

Check that the injector harness is'nt cracked and falling to bits allowing the wires to short.

FPR short rubber hose cracked,holed etc,check the dist's connector is ok,fuel press. ok?,cracked lambda probe wiring?,engine earths all clean and tight?,ECU's connector pins corroded?.

Def. change the CTS with an O/E one and G60s do have two micro switchs,1 idle contact and 1 full throttle.

Drown the ISV in carb cleaner untill clean,check that the idle switch isn't sticking shut aswell.

What chip are you running?,'cos it also sounds like your classic bloody digi-lag which i personally hate,why the hell Vw put such a program into their eeproms beats me..

[TomD 0]

The Chips a SNS Stage 5 (??) The anti lag one, with a 68mm pulley.

 

How much are the Blue temp sensors?

 

Might go to VAG in the morning and order one!

 

Cheers,

Tom

[Rustynuts 0]

Before you do anything make sure that the 1m vac pipe is connected to the right lug of the throttle body, they other one goes to the CO pot if i remember rightly. Anyway, just swap them over and see if that sorts out the idling probs. The reason it would run so bad in this form is due to the two connections being different sides of the thottle butterflies. If you have the 1m to ecu vac pipe on the wrong side it reads boost all of the time and therefore the ecu creates overfueling.

[flusted 0]

The top nipple is the ecu one,the other is for the carbon cannister.

Mine does this when cold and im putting it down to gsf temp sensor.

[TomD 0]

Ok, I stripped down the ISV and Throttle body today, cleaned everything up with carb cleaner, checked all the wires and connections and re wrapped some of the wiring in tape as the old stuff was a bit knackered.

 

 

My exhaust has been making a really odd noise for the last week or so I took it off to have a look...

 

...the centre box (the one under the passenger seats) had snapped where the pipe meets it and looked like it was leaking a fair bit

 

Could that have caused the probs? I've got the miltek back on now so we'll see what happens!

 

Which side does the vaccum hose need to be connected? I'm guessing the inlet manifold side of the butterflies as opposed to the charger side? The other one definitely went to the Carbon Canister and is now blanked off, but I guess I could have blanked off the wrong one!

 

Gonna take the car for a spin and see how its running. :) :)

 

 

P.S. Just had a thought...it could well be overfueling, as it does have a habit of producing flames when I change out of 2nd or 3rd over 6k. I'll check it out!

[TomD 0]

Back from the test run....

 

 

...feels just how it should do! smooth all throught the throttle position and on idle (although it idles too0 high at the now!) :D :D :D

 

I'm pretty sure it was the exhaust problems that were causing it, I guess it was messing with the back pressure or the lambda probe or something.

 

But now the car's pretty loud again...but it does sound sweet!

 

If I took the car to powerflow could they put a silencer box where the cat used to be to quieten it down a bit?

 

One Problem though....its taking a little while to reutrn to idle now. I had a fiddle with the idle adjustment screw and I think I've sorted it, but can you reset the ISV like on 8v digi's?

 

(IIRC it's disconnect the blue temp sensor and rev the engine over 3k 3 times???)

 

Cheers for your input guys, think I'll still change the CTS if its not too expensive just to be on the safe side, but *fingers crossed* it seems to be ok! :)

 

I love my C again! :)

[Henny 0]

yup, if you change the idle, you need to have disconnected the BTS before you adjust it... rev to over 3K 3 times to reset the ISV the same as the GTI (it's basically the same digifant system, just with a MAP sensor inside the ECU... 8) )

[TomD 0]

Cheers Henny!

 

Its all running well now...forgot how good it sounded with the milltek on...just need to get it a bit quieter! :)