nago555

i have a uk my99 turbo with a magnex decat pipe with ss back box running 0.9kg/cm2 on the lamco gauge with a piper cross panel filter after fitting a K&N induction kit there was a noticeable increase in power spool up and the boost pressure raised to 1-1.1kg/cm2 after about 3-4 weeks i was driving given it a bit of stick the boost raised to its normal 1kg/cm2 then lost 80% of power and boost droped back to 0.5kg/cm2 no engine check light got home checked all hoses and wires all ok went back out all back to normal untill to day same problem under what conditions does the ecu cut boost and what pressure is overboost any help would be great.

TonyBurns

iTrader: (3)

You will only get overboost in 3rd 4th and 5th gears, it feels like its pulsating, like you blipping the throttle.
What sort of driving are you doing when you get it??

Tony

nago555

normal sort of town driving then pull on to a dual carrige way give it some stick in 2nd and 3rd than the boost drops away untill you turn the engine of and start it again then its ok look back seems to happen on warm days if this helps

TonyBurns

iTrader: (3)

Does your boost seem to drop off after 4k rpm?

Tony

RT

1. Plse punctuate. It makes it easier to read.

2. Could you be encountering the dreaded "noise emmissions" thing? What gear were you in when the boost cut to 0.5bar? If you were in second, then its almost certainly that.

3. If its not that, then a point to keep in mind is that the "safe mode" boost of the ECU is 0.5bar. It could be sensing det and retarding timing / reducing boost in an attempt to protect the engine. Did you intercooler have lots of heat soak prior to you giving it some throttle?

Cheers.

[Edited by RT - 6/30/2002 3:15:54 PM]

silver:scooby

Have you tried cleaning the boost solinoid and pipe work did not work on my car but you never no!