backfiring....

datsunboy · Post by **datsunboy** » Sun Apr 06, 2008 10:06 pm

hey guys.....I had my first decent play with nistune today....
its a CA18 with a T28, 550cc inj, and Z32 MAF.
were running 45psi fuel pressure.

we only had a bit of a play....but we got it to run pretty close to 14.7 at idle....but it was still a bit rich up top, but we'll play with that more later.

problem id, that its backfiring real bad on decel?

it idles a little rough, which I think is because I havent set the latency up properly yet.....any tips on doing that?.....could that be causing the backfiring?

heres a very quick log file ( the log file stops recording all by itself???? )

Fusion Ed · Post by **Fusion Ed** » Sun Apr 06, 2008 11:46 pm

Backfiring on over run is a lean condition (not really dangerous in any way) Is the TPS working correctly? It needs to detect when the throttle is closed to cut off the fuel supply.

datsunboy · Post by **datsunboy** » Mon Apr 07, 2008 12:12 am

wierd, I wouldve thought that backfiring was due to too much fuel
but the wideband was off the chart lean.....lol
the TPS appears to be working....i remember the TPS closed light on the cosult display being on when were were tuning in the driveway....
but if you look through the log file....it says TPS is still reading 0.3volts on decel.....maybe its not set properly then? I'll take a look at it
thanks for the quick suggestion

Matt · Post by **Matt** » Mon Apr 07, 2008 12:12 am

yeah when TPS indicates acceleration pedal released, if above RPM in the fuel cut table for specified temp is then fuel should be cut until Fuel Recover RPM is reached for specified temp

datsunboy · Post by **datsunboy** » Mon Apr 07, 2008 12:21 am

while your here matt.....have a look at that log.....its showing me values of TP of like 2000-4000 ??????