roadtrip_69
15+ Year Contributor
- 66
- 9
- Apr 18, 2008
-
Cincinnati,
Ohio
All, been tweaking fuel ratios and and fuel trims. Got all the trims dialed in better than ever. Have the rear 02 (wideband) within a couple percent of whats being called for. Knock is mostly non-existent. But when doing a pull, I'm getting a backfire. Where it pops out the exhaust, don't know if its followed by flames due to being too rich or not as I can't obviously see that while driving.
Logs look normal to me, with off throttle being pretty apparent, after I feel the backfire, I let off the throttle. Seems to occur at high boost, so there's that but also at only 50 percent throttle. Though to be honest I feel like that might not be accurate in logs as, as I was testing, I was giving it closer to 75-100 percent I feel.
Most mods are in my profile. But I have 850CC FIC injectors, upgraded fuel pump wiring, 20g turbo, Mishimoto FMIC, a 320 LPH fuel pump, aeromotive fuel pressure regulator, set to standard psi. I have replaced a bad ignition coil after I did get a couple misfires and codes. That seems to be resolved. I did upgrade spark plugs with NGK '8s' Iridium (I had copper '7's doing the same thing). Gapped at .028.
So I cant figure out for the life of me what is going on. In the past I wasn't even getting ANY knock, on the log I'm attaching I did have 2 instances of knock right next to each other. but even then only 3/4 counts respectively. Considering the boost level at the time. Not too bad. But even in the past before I got fuel management dialed in ?? and was getting knock a lot it would "stumble" but not back fire/pop(exhaust). So this is a new issue.
One more thing of note is I do have meth injection, that starts injecting at 10 psi, progressively till it hits the max the nozzle can put out at 26 PSI and there after.
Anybody have a similar issue or who can read logs better than I to determine what is actually going on. My IDC based on IPW doesn't look like I'm running out of fuel at all, so its baffling.
Log is from ECUFLASH
Thanks
Logs look normal to me, with off throttle being pretty apparent, after I feel the backfire, I let off the throttle. Seems to occur at high boost, so there's that but also at only 50 percent throttle. Though to be honest I feel like that might not be accurate in logs as, as I was testing, I was giving it closer to 75-100 percent I feel.
Most mods are in my profile. But I have 850CC FIC injectors, upgraded fuel pump wiring, 20g turbo, Mishimoto FMIC, a 320 LPH fuel pump, aeromotive fuel pressure regulator, set to standard psi. I have replaced a bad ignition coil after I did get a couple misfires and codes. That seems to be resolved. I did upgrade spark plugs with NGK '8s' Iridium (I had copper '7's doing the same thing). Gapped at .028.
So I cant figure out for the life of me what is going on. In the past I wasn't even getting ANY knock, on the log I'm attaching I did have 2 instances of knock right next to each other. but even then only 3/4 counts respectively. Considering the boost level at the time. Not too bad. But even in the past before I got fuel management dialed in ?? and was getting knock a lot it would "stumble" but not back fire/pop(exhaust). So this is a new issue.
One more thing of note is I do have meth injection, that starts injecting at 10 psi, progressively till it hits the max the nozzle can put out at 26 PSI and there after.
Anybody have a similar issue or who can read logs better than I to determine what is actually going on. My IDC based on IPW doesn't look like I'm running out of fuel at all, so its baffling.
Log is from ECUFLASH
Thanks
