G40 rough on start up...

[DKnight]

well my g40 over the last 6 months or so has started to run really rough on start up, so much so it sounds like a misfire, it only does it for about 2 minutes then it runs fine, no problems at all...

now i have checked the usual things, dizzy cap arm, leads plugs, are new from about a year ago
coil i ve checked and tested, ecu chip i have swapped still same

timing is correct too

when it is running rough there is a strong smell of fuel so i really do think it is a fueling issue, how can you check the injectors? maybe even a blocked line? filter swap maybe?

any ideas be great

cheers

Dan

[hayesey]

hmm maybe it could be a sticky injector that starts working properly after a bit?

Easiest way to check is probably going to be to remove the fuel rail, point the injectors into a bowl and then get someone to try starting the engine.  As that's happening watch for nice even spray patterns coming out of the injectors and that when they stop trying to start the car none of them leak fuel.

Alternatively, if you have some spare injectors put them in.

[Andy]

Blue temp sender?
Fuel leak?

[DKnight]

blue temp sender i need to check yeah, isnt coming up with any faults tho

and no fuel smell or signs of leak

i will try the blue temp and hayeseys idea with the injectors

and report back

[hayesey]

well there is a fuel smell isnt there, but we had a good look for leaks and couldn't see anything.  no sign of fuel spraying out when you were trying to start it.

[supercharged spaniel]

sounds exactly like my problem...i have tried every thing!!! filters/changed injectors/timing/new leads/plugs/dizzy/everything and i still have it...worse when cold lasts about 30 secs after start up from cold goes quickly if you drive...do you have a decat pipe on?  mine started after i fitted a decat...could just be coincidence.  car still drives mint after this has gone though. let me know im very very interested.

[Nick_S]

You could be onto something there Dan. Always wondered why ETKA list a different ECU for non-cat G40's!

[NeilG40]

Mine used to chug (the best way I can describe it) for about a minute when first starting in the morning but it didn't affect how it drove though, the funny thing is my old mk2 golf 1.3 used to do exactly the same thing.

I never found out what was causing it in either cars and I imagine when the g40 finally gets out of the garage again it'll do it then.

[tdh-syorks]

mine used to run very rich and there was a really strong fuel smell, that was the blue temp sender no good.

[Alex]

Mine does this as well, but I'm guessing it's because I need to take it for a long motorway drive. It's doing the trip to work (15 miles down the A1) every day but that's as far as I take it usually.

[PeteG40]

in this its likely to be something electrical in my opinion causing over fueling - like lambda, alternator, injectors, blue temp sender, chip etc.  i suppose just swap all with those from a known good car and see if anything makes a difference

[supercharged spaniel]

the only thing i havent changed is the alternator..i occasionally get the battery light on start up when cold but the battery is new and ive done the voltage check thing with a multi meter which was fine so im guessing its just a tired/aging alternator, never has any bother starting starts first time every time...can't see this problem being alternator related to be honest.  ive changed everything else including vag lambda and i always seem to remember noticing this after i fitted the vag decat about 18 month back...any ideas?  ive lived with it for ages now doing about 20k with the problem.... be interesting see what dk says...

[supercharged spaniel]

Mine used to chug (the best way I can describe it) for about a minute when first starting in the morning but it didn't affect how it drove though, the funny thing is my old mk2 golf 1.3 used to do exactly the same thing.

I never found out what was causing it in either cars and I imagine when the g40 finally gets out of the garage again it'll do it then.

thats the best way i can decribe it 'chug' too

[DKnight]

yeah it is a chug, and mine does have a decat yes!

if i rev the chug just ups its speed, until after a few minutes, it goes away

i will be swapping the decat for a cat soon so i will see how it goes!

good input from all here, i hope we sort it

[NeilG40]

The fact that my golf, which was a 1986 carb'd version with a mechanical fuel pump, did it makes me think that it's probably not one of the sensors.