Lumpy revs after starting *solved!*

[Stoned]

Not a big problem as it goes away after 20 seconds of idling, but I have noticed when I start the car for the first 20 seconds she idles lumpy.

If you press on the throttle it actually makes the revs dip instead of rise through the problem - like it's about to conk out.

But leave it for 20-25 second and the revs pick up and all is like normal again

Any ideas?

 

[Fast Guy]

It sounds like you could either be cold fouling or have a slight ignition problem :? possibly even abit of damp in the ignition.

What plugs are you running, have you checked the gaps and condition recently? When was the ignition stuff changed last?

 

[GTIR-LOZ]

this is what ive got mate, im trying to sort it out at the mo, will let you know, im sure its a fueling problem as mine only happens after leaving her overnight

 

[Fast Guy]

I guess there's always the possiblity of a leaky injector.

It might help if you could isolate which cylinder it is, if it's only one.

 

[Stoned]

Hmm I see

Dont think it's fueling. It's got a new walbro pump on there with a new filter. Also recent oil change and filter.

Speak leads, dizzy cap and rotor arm were all changed a few months back also.

Sparks are getting on a bit now. Maybe I should change them?
Which ones should I get for running up to 1.1bar boost?

 

[Stoned]

I changed the spark plugs and it made no difference, but now get this.

Optimax is back in my area and yesterday I filled up with a tank of that instead of Tesco 99ron i've been using while it was unavailable, and straight away my car is idling normally again

No drop on optimax whatsoever

So clearly it's not so happy with Tesco 99

 

[Dooie Pop Pop]

thats wierd :?

 

[antgtir]

Has the R been specifically tuned for the 98RON fuel?? It is weird that it would change, unless the fuel from Tesco is not good quality and crap in the fuel was somehow getting through the filter and into the engine etc, baffled with that one. :?

Ant.

 

[Stoned]

No it hasnt. When I took it to Engine Advantages he did restard the ignition slightly to stop it pinking at the top end, but theres no chip or controller on it yet that specifically takes advantage of 98ron fuel. Though hopefully it's in the post!

 

[GTIR-LOZ]

hmm i use tesco as well, but im sure it was doing it when i used optimax it did it this morning next fuel tank i will try optimax again although its 6 pence more expensive a litre

 

[antgtir]

hmm i use tesco as well, but im sure it was doing it when i used optimax it did it this morning next fuel tank i will try optimax again although its 6 pence more expensive a litre

6p :shock: didnt think the gap between the 99RON Tesco fuel and 98RON Optimax fuel was that big :? you are using Tesco 99Ron and not 95 lol

I would try espcially if it has really only just started since you used the tesco fuel, this would be a big let down for Tesco if it was found that their fuel was causing problems.

Ant.

 

[Dooie Pop Pop]

only a 2pence difference at my local' s

optimax went down and tesco' s went up :roll:

 

[GTIR-LOZ]

it was the tescos fuel since switching to optimax again all is well, the reason it was a 6 pence price dif as the garage right near me is about 4p a liter more than the shell about 2 miles down the road theiving buggers