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View Full Version : s13 sr running backwards, rich at idle lean in boost-help


Destructodc74
10-03-2010, 02:51 PM
i have an s13 with a redtop sr
-fmic and full exhaust
-walbro 255
-stock boost with an s14 t28

the car runs pig rich at idle. like in the 11s, (i have a wideband) and starts going lean after 4k rpms ive done the following
-boost leak test
-changed fuel pump
-new z32 fuel filter
-wired fuel pump directly to the battery has 13.5 volts running now
-changed fpr with known good one
-changed maf

any ideas? it has to be an electrical problem. it started after i let my car sit 2 days without a battery and relocated the battery to the back seat due to puncturing my old battery i had up front.
someone point me in the right direction please

Destructodc74
10-04-2010, 07:48 AM
noone has any input?

knate
10-08-2010, 03:13 PM
Where are you connecting your boost/vacuum to the FPR from? It sounds like there might be a leak in that source. Under vacuum your FPR should be leaning it out some, and under boost should be increasing pressure to make it more rich.

Make sure you have a good solid line going to the manifold somewhere with no leaks. Maybe when replacing the battery the other end of that hose came loose?

Destructodc74
10-11-2010, 11:31 AM
Where are you connecting your boost/vacuum to the FPR from? It sounds like there might be a leak in that source. Under vacuum your FPR should be leaning it out some, and under boost should be increasing pressure to make it more rich.

Make sure you have a good solid line going to the manifold somewhere with no leaks. Maybe when replacing the battery the other end of that hose came loose?

thanks for the input. but i actually figured it out. when i let my car sit i forgot i rewired my fans to turn on with the key and i jumped the power from the 12v wire on the harness... yeah dont do that lol. it was sucking all the power from my harness so my ignition system was failing causing it to run rich at idle and choke out under high rpms. i now have my fans running off a relay instead. thanks for the help though!