Problems on boost

[c5 swh]

Ive done 450 miles on my rebuilt engine, whilst the car is running in im only running 10psi boost. Now if i put my foot down and its on boost it stutters and sounds like misfiring. Its fine apart from that.

What could be causing this?

[gttjames]

What have you replaced?

1st place id be looking is the dizzy, plugs, leads

[c5 swh]

replaced pretty much everything for new. It runs fine off boost and most time on boost, but occasioanlly when you put your foot down it as the problems.

Ive cleaned all the carb out. Ive been recomened looking at fuel pressure.

Im currently running the standard fuel pump should i consider getting the uprated one?

If so where the cheapest palce to get one from.

[c5 swh]

Ok, ive checked all leads, dizzy cap & arm, plugs. All look like new.

Its a weird probelm, as sometimes its fine.

Like i said going around town its absoluly brilliant. But for a example yesterday i was going down a slip road to join dual carraigeway so put my foot down and it speeds up but then starts hestitaing, stuttering and holding back.

Also what ive noticed is the boost is set at 10psi whens its playing up the boost will not go any higher then 5-7psi whilst stuttering etc, but when its running fine it boosts straight to 10psi.

Any help much apprecaited:cool:

[Markey Mark (BD)]

Is your overboost switch connected?

[c5 swh]

Is your overboost switch connected?

No its not connected:crap:

[Markey Mark (BD)]

Thats

[Markey Mark (BD)]

Thats ok mate doesn't need to be but does need to be held away safely so they don't make contact, just sounded like the overboost was kicking in.

Could possibly have a problem with your carb if everything else is fine

[dave r5]

i had a problem like that, it was the knock sencor,

wrth a try

[c5 swh]

Ive ordered some new spark plugs to try. Is there anyway of checking the knock sensor? Can i just unclip it and see if it runs ok with out?

If that all fails ill have to take carb off and give it another good clean? If you have seen my other posts ive had problems with contaminated fuel causing a dodgy idle but thats all fine now?

Anything else?

[Markey Mark (BD)]

To see if its the knock sensor just disconnect it from the AEI and see how it performs

[c5 swh]

Right good news i think,

Cleaned the idle jet, re did mixture. Took it for a run and still the same was fine until you put foot to floor. So pulled over and disconnected the knock sensor at the joiner at bulkhead and now its perfect, foot to the floor and boost perfectly no hestitaion etc.

So looks as if it knock sensor. Now does this mean the kncok sensor is shot? Should i replace or just leave it disconcected? is it ok disconeected?

thanks everyone:cool::)