Assassin

iTrader: (3)

need some help w/this, if I'm stoped and I slowly bring the rev's up I can see the o2readings going lean and my wideband is showing the same, it sounds like holding the throttle at say 2k and instead of a nice smooth engine you hear a low spot every few seconds.. know what I mean?... I would think it has to do w/fuel if its going lean(from 14.6 up to mid 16ish), I'm in open loop and maf is disabled, though it does this reguardless, I'm useing hptuners if anybody can point me in the right direction

hpcubed

It sounds like it misses and then goes lean for a split second when you hold the throttle at about 2K? My car is doing it after I swapped in my 60 lb inj. on my 402. It sounds like an injector does not fire. I am going to put in the stock inj. and see if it does it.

This may not be the cause. But when I first installed my 60 lb injectors on my 346 using a 2001 operating system, I could not rev the motor past 2.5K. It would miss and go lean. Then I swapped in the injector parameters from my 99 OS and everything was fine. The inj. flow rate was the same in either circumstance.

Anyone else???

hpcubed

I put my stock 26 lb inj back in and the issue is gone so it has something to do with the 60 lb inj and the parameters I am using. Or maybe a bad inj.?? What size inj. are you running?

I think our issues are related though so hopefully we can get to the bottom of this.

Assassin

iTrader: (3)

aahhh haahh,, so thats what it is, I've got lucas 42lb injectors but the ifr table I had to modify just a slight bit to get rid of some bucking, instead of using 58psi for the equation I used 60psi and it runs alot smoother but that would explain the reving/mis problem, its not that I ever just sit and hold my engine at 2k just to listen to it but I was doing some tuning and notised it... thanks for the help..

hpcubed

Ah but you should be able to rev it anywhere you want and it should be smooth. I listen to my motor at every RPM and I have to have it perfect. The table that helped me with my 346 motor was the "Small Pulse Adjust" table. I am not sure yet why there is a difference for a different size motor. Guess I need to investigate some more.

When you used 60 psi instead of 58 you leaned out the motor slightly. You should not have any erratic jumps in AFR because of this.