still hesitent top end

JohnP · September 05, 2007, 10:45:12 AM

well i posted ages ago about having a dodgy top-end after around 5-6k.

i\'ve replaced plugs (lovely job.....) but tbh the old plugs were in very good condition anyway.. anyway, this hasnt solved the problem.

when i accelerate hard, 1-5.5k seems fine, above that the car starts to fight itself. It still accelerates, but is inconsistent.

the problem is intermitent. sometimes i can plant the throttle, and i crap myself cos it actually works fine once in a blue moon.

the only synptom i can describe to you, is a weird air-pressure related pop/boing noise. its not the dimented moo\'ing, and its not the stock BOV\'s.. and never does it below 5k revs..

strange_days_uk · September 05, 2007, 11:16:33 AM

do you have stock mid pipe ? perhaps the cat is screwed

Jit · September 05, 2007, 11:22:31 AM

if youre on twins have a check to see if youre check valve which is in between the hose which joins the pressure chamber to the y pipe is still a one way valve and hasnt become 2 way... a sympton of that one going 2 way is that the air escapes back thru the check valve from the presure chamber causing a loss off boost pressure particularly if youve been driving a few seconds off boost and then floor it...

JohnP · September 05, 2007, 11:56:39 AM

one2watch. got a picture of the valve i need to check? I\'ve only had her a couple of months and i\'m not the most familiar with the setup yet

and yes, i do have a stock midpipe.. i did wonder if it was a problem with air getting away from the turbos..

Red Leader · September 05, 2007, 12:43:50 PM

Yes i remember your post. I to had the same problem.
Mine turned out to be the alarm. Was fiddling around and found the alarm control box. On the main power connector i found one of the pins had overheated badly to the point the wire was just holding together.
I cut the wires off and wired them to a 60amp electrical connector, the type used for mains wiring. Not had a problem since. Guess it was just a poor joint the lead to the overheating.

JohnP · September 05, 2007, 01:54:43 PM

so how was the alarm affecting the performance of the car?

Jono FD3 · September 05, 2007, 04:33:18 PM

What boost are you running mate??? as I have heard anything above 5500 rpm on stock plugs (boosting over .85 bar) the extra boost causes a missfire!!

Jono

JohnP · September 05, 2007, 10:15:29 PM

soon to find out, fitting the vacuum hose for my boost gauge tomorrow.

i did wonder if it had been remapped at some point and then returned to stock parts wise. will follow this up tomorrow

keep the suggestions coming, cant beat having more than one point of view!

antnicuk · September 05, 2007, 10:59:40 PM

Quote from: Red LeaderYes i remember your post. I to had the same problem.
Mine turned out to be the alarm. Was fiddling around and found the alarm control box. On the main power connector i found one of the pins had overheated badly to the point the wire was just holding together.
I cut the wires off and wired them to a 60amp electrical connector, the type used for mains wiring. Not had a problem since. Guess it was just a poor joint the lead to the overheating.

funny you should mention alarms causing problems, there have been huge ructions on this site about alarms and whether they can cause engine problems.

Mine held back at 0.9 bar on stock plugs but if you have a stock set up then something is wrong if you are running that much boost.

still hesitent top end

strange_days_uk