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MAP spikes

Posted: Tue Jul 14, 2009 12:53 pm
by jameso
Hi
I'm running a 2.7l 4 cylinder NA engine (Porsche 944) on Microsquirt version 1fuel and spark. The car is running well but I am getting MAP spikes fairly often.
The MAP sensor is a 3bar GM unit and is fitted right back by the ECU. I have fitted a small inline fuel filter and also a 1.5 mm restriction in the pipework but I am still getting Accel enrichment spikes.
I have tapped into the vac line just behind the throttle plate which goes to the fuel pressure regulator, could that cause issues?

Thanks

James

Re: MAP spikes

Posted: Wed Jul 15, 2009 5:28 am
by Matt Cramer
Might want to try tapping a different spot, away from the throttle.

Re: MAP spikes

Posted: Thu Jul 16, 2009 9:47 am
by jameso
Well 4 hours later I have a take off point fitted to the largest part of the plenum.
Start the car and I still get the spikes, it has improved now and only does it on idle so far today driving it seems ok. Will need a long drive to be sure.
Can't do too many miles at the moment as British summertime (torrential rain) has kicked in with a vengance.
Any other idea's?

Thanks

James

Re: MAP spikes

Posted: Thu Oct 08, 2009 5:44 am
by gboezio
One mm restrictor should be enough, but you can disable the MAP accel enrichment and use the throttle only, or raise the enrich threshold