[Mk2] [NA] running lumpy like on 2 cylinders

[mjones16]

3sge running fine for around 30 seconds then runs really lumpy.

I have fitted a japspeed decat tonight and it now runs even worse.

No engine management lights or that on. What can this be ?

[mr2matt]

Which generation of 3SGE is it? And 30 seconds from what? Starting up I presume.

Has it been well serviced over it's life? Just a guess but sounds like it's a Lambda sensor or similar that might be causing it.

Also have you checked for error codes on the ECU?

[mjones16]

It's a rev2 auto

Yes from start up. Going to do fault code check tomorrow

[Grazzy]

I would try disconnecting the battery for a little bit. reconnect 10mins later.

[aussieGT]

My n/a sounded like an old VW beetle and was running on two or three cylinders for part of the recent Wales run.

No fault codes showed, but was found that the sockets around plugs 3 & 4 were soaking with water which caused my problem. It was intermittent.

[mjones16]

No fault codes either

When engine is idling at temperature it wants to stall.

Do u think I should change the ignition leads see what happens?

[aussieGT]

Just pull them out first and have a look.