Whats wrong with my car ?

[ian4455]

My 3b drove for the first time today for MOT. Running sweet as a nut to the Petrol Station driving nice and steady in traffic.
Left the petrol station car starting to warm up and as it got warmed up it started to run lumpy. Idle whilst sat at traffic lights was very lumpy running about 600rpm, carefully driving back home it poped a few times through the exhaust when i let off the accelerator.

Haven't nailed the car just driving in heavy traffic, no boost used as not gone above 2000rpm.

Changes made to the car are - New Plugs, 11mm Rotor Arm, New Dizzy Cap, 330 cc injectors, 4 Bar FPR, RS2 Hybrid Turbo. ECU altered to suit with proven chip set and 3 bar MAP.

I've no way for checking for faults as haven't any equipment, all i know is it was running fine until it started to warm up ......any idea's ???

[K Simmonds]

MAF or MAF conector would be my first thoughts, are you sure the chip set you have is for 330 injectors at 4 Bar?

[Big Lee M]

Throttle position sensor, ok on low revs but as soon as you put a little load on its all over the place, check to
Make sure it's plugged in correctly.

[ian4455]

tick over has dropped and very lumpy, very little load on the engine as i was driving in heavy traffic 20mph or less.

think it strange it was ok at cold, going to start the car later today and see if the problems gone when cold.

One consideration, i had the turbo passing oil hotside, think its now sorted out but could the Lamda make it run like this ?

[s2_wot]

i've seen this before on an ABY, the ISV wasn't fully tightened on one of the clamps. Might be worth a quick check on the pipes in that area.

[ian4455]

Isv ???

[s2_wot]

the idle stabilisation valve. iirc it's got 3 ports on it and it's located at the bulkheadside of the throttle body.

[ian4455]

Ok, nipped home at lunch time. Car's fine when cold. This problem only happens when warm. !!

Warm it up then idle is lumpy and holding the throttle on with the car sat still is lumpy also through the rev range ?!?!

Could this be the plugs ?

[Dobby84]

I had similar problems and it turned out to be the Idle control valve, gave it a clean out and it sorted the problem, may be worth checking the MAF as suggestedby K Simmonds. Also check for any boost leaks etc.

[simon20vq]

I had a similar issue and the 02 sensor had become slightly unpluged on the bulk head!

[prj]

As always, it could be a million different things.
Fixing it by trying to swap a million different things will just make you frustrated.

If you are getting so severe problems there must be fault codes stored in the ECU.
Blink them out and see what is wrong.

Typing "I had a similar problem, and this sorted it for me" is pretty useless, because it could be bad MAF, bad MAF connector, air leaks, O2 sensor, stuck ISV, trigger errors, and a host of other things.
First thing is always air leak test and pulling codes. If that does not point to the problem, then start guessing and swapping parts randomly.

[ian4455]

Seems to me like its ignition, but agree could also be a number of things. All i know for sure is prior to changing the parts listed the car was fine.

New plugs fitted but the cardboard box was dropped on my tiled kitchen floor, maybe caused a problem? I'll re-fit the old plugs just in case.

I've a blinker but how do you fit these ?

[merlin's S4]

Deleted

[newsh]

The method for reading the blink codes is on S2Central. Easy to do, white/black/blue connectors in the fuse box normally on a 3B

[ian4455]

Problem sorted, old plugs installed. Must have damaged the new ones when i dropped the box on the floor.