20VT flat spots + misfire

[LazyLunatic]

First thing - coilpack. A full new set is on the list!

I understand the coilpacks can produce a misfire. Now the other problem is flat spots. I only have this problem on when I run at 16psi, not 6psi and it appears to be all over the rev range, but only on boost, like 2.5-3k+. Runs smooth and revs fine at low boost.

I can't see any problems with any of the vacuum piping or any other piping. Not sure if blocked breathers, throttle body, etc, can cause it...

I'm hoping new coilpacks will solve it but just wondered if anyone knows what else might be the causing the problem.

Thanks

[Hulmie]

first things first, do a throttle body clean. Next check PCV system. Any problems with Temp not getting up to 90 degrees or getting there and then just dropping off? does car run better without MAF plugged in?

[LazyLunatic]

first things first, do a throttle body clean. Next check PCV system. Any problems with Temp not getting up to 90 degrees or getting there and then just dropping off? does car run better without MAF plugged in?

Yer, I need to check the PCV system and clean the throttle body! Thanks bud. One of the breather pipes coming off the inlet manifold looked a bit oily, so I'm sure that's not good. It's probably not so bad as the problem only occurs when I flick the boost up.

Not sure on temp as thats the one of the last things I need to sort. My gauge doesn't read properly, going to try a new temp sender from VW today; might be a faulty GSF part (wouldn't suprise me).

It runs a MAP sensor and I don't want to unplug that cause last time I did that (well it unplugged itself ) it ran like a bag of sh!t.

[Hulmie]

you could probably do with a catch can as the engines are heavy breathers. And when fitting a catch can replace the pcv system piping.

If you have a faulty temp sensor then this could cause your running issues

[topher]

bare in mind this is a conversion on mbe management so most of what we know about the 1.8t when controlled by a bosch ecu is almost irrelevant

i'd be concerned that it's a fuelling issue, infact on any standalone setup i'd be concerned about fuelling issues 24/7 and if you don't have a decent wideband in the car GET ONE!

anyway in answer to your question yes failing coilpacks can cause flat spots as well as misfires, i have a set here that are absolutely fine until you try to pull past 95mph and then you get nothing.