My MY99 Impreza was off road for about 8 months and when I got it back on the road I noticed on my AFR gauge I was getting around 13.5:1 when on boost. I got it booked in for a dyno session and this confirmed it was running lean and detting when boost started to build. Now the fuel pressure was then raised to around 4bar above manifold pressure and this lowered the AFR and stopped the det, but was told I needed a remap and shouldn't give the car any stick untill then. The car had an Ecutek remap a few years ago by Pat and has had no issues since. Now the only thing that has changed since the map is a silicon induction hose. Would the hose effect the MAF signal in anyway? It is a bigger diameter than normal, but is still after the MAF housing so I wouldn't have thought it would. I also wouldn't have thought the car needed a remap to sort as if the fuelling has changed all of a sudden then surely there is a fault somewhere? What are peoples thoughts on this, would the cause most likely be a faulty MAF or a leak in the inlet pipework after the MAF? Or could there be a problem elsewhere? The fuel pump is a Walboro and has been tested to be fine as is the Aeromotive FPR.

Thanks in advance, Shane.

 

My guess would be MAF - they are known to be a bit unreliable on the 99/00 cars.

 

needs mapping for the silicone hose change.

could also be maf but ti still needs mapping for silicone hose change and maf can be checked at time of mapping

Simon

 

Thanks for the advice, I'm saving for a Simtek at the mo, so have left it alone for the time being. The car is only driven once a week to keep things running. IIRC it did start acting up before the inlet hose was added so probably is MAF again, can't wait to get rid of it, had 4 in 3 years. It does have a problem with boost stability since the inlet was changed and I get compressor surge sometimes when accelerating. So remap it is.

 

sounds best move..

some cars seem to eat mafs, others don't.. sometimes with the same setup too

Simon