Hi all, i've had a look through old threads but none of them mention my problem exactly. Its happened twice now.

 

On my way to work, start up car runs fine no issues, driving okay with small bursts of on boost fun. Then i give it the berries and it starts misfireing, coughing and splutering and doesnt respond to the throttle. This went on for a couple of miles and then cleared itself. On my way home i connect up the Datascan software, do the same and car runs perfect (WTF!!??).

 

There are no error codes (only 55)

 

I've recently changed the MAF due to idling problems, done a boost leak check, cleaned all of the connectors, etc, etc.

 

If the Det sensor gets triggered will the car run like a bag of poo afterwards or will it settle back to normal but just not go over 7psi boost?

 

Could it be the cooler morning air causing problems?

 

The car is a j-spec TT with decats, filter, zorst, chip and boost jets running at 14psi.

 

please help

 

Mark

Could be as simply as a coilpack connector not seating properly. Happened to me once, was once off my a mm or so but enough to cause a missfire

 

Vijay

Cheers Vijay, i'll have look tonight

How old r ur spark plugs mate?As ive had my plugs crack up on me and it caused mine to run the same misfire under full throttle.

Mine had a leak on the clutch booster and it ran fine until Ihoofed it and it then misfired. Problem with the one way valve?

Cheers guys.

Vijay - I've checked all of the coil pack connectors and they are okay.

 

TT Dan - The spark plugs are a year or so old but they were fine when i checked them a couple of weeks ago (when i first started having problems). Would this explain the running okay then rubbish after boost?

 

Radron - I replaced the clutch booster a couple of years ago when the clutch went all heavy on me. The clutch seems ok at the momment though. How could you tell if it was the one way valve, where abouts is it?

 

Typically the car ran like a bag of sh1t on the way home last night (in the storms). It wouldn't rev, kept missing and stalling. The only way i could get it home was to unplug the MAF.

I replaced the MAF with a second hand one from SWZ a couple of weeks ago when the car didn't want to idle but would rev and run okay. Its run okay up till now. When i put the old MAF back on it revs and doesn't miss but it still wont idle. I've checked the wiring back to the ECU and that is all okay.I've also made up a boost leak checker but can't hear any leaks. I'm at a bit of a loss now.....

First thing I would try cos it doesn't cost much is to clean up all your connectors and reset your ECU

Hi Vijay, I cleaned all of the connectors i could get to the last time the car played up (a few weeks ago). I've been using Datascan to log what is going on but everything appears to be working normally (???). Each time i have unplugged the MAF I've had to reset the ECU, so i know that is okay.

Are you aware of any Zed speciallists near London?

 

Just drove the car again, all okay. Then pull in to my drive and its starts to stall again? Really confused.

 

Cheers, Mark