1G Random stutter causing knock

[perrytheplatypus157]

What could be causing a random misfire? It seems that the only time the car starts to knock is once it misfires. We've replaced the plugs(Br7es gapped at .026), wires(stock 7mm), ignition coil, TB, different injectors(450s, 560s, and 1000s) battery(XS deep cycle) and voltage doesn't seem to make a difference nor does throttle position or AFR. In the log I've posted, there may be some times that the belt is slipping so voltage drops, but the issue has been around longer than the belt slip. The alternator tested good twice by two different auto stores. Any guesses? Thanks

Specs:
1g manual
14b turbo
91 octane
Exhaust
EVO MAF
Injectors
FMIC
Aeromotive 320 pump rewired
Fuel lab AFPR

 

[AWD-Tony]

Your idle is way high and your MAF slider needs work. You had 1000cc injectors in this log?

 

[AWD-Tony]

If you had the tps off, make sure it’s on correctly. There are two prongs at the end of the tb shaft that slides into the two slots on the tps. Dial in your idle first and post another log

 

[perrytheplatypus157]

Yes, they're 1000s at this point. It seems that it needs a lot of dead time to even start and stay running though.

 

[AWD-Tony]

In the log you just posted, injector size is 1450s. There's something goofy with this site where viewers see a different injector size then what you actually have in link so just want to make sure that it's still 1000's on your end. Can you post a log of car idling? Have you done BLT, check timing, check exhaust leak, check timing marks, base fuel pressure with vacuum hose off?

Below is video how to dial in MAF. But you need to get everything dialed in BEFORE tuning.

You must be logged in to view this image or video.

 

[perrytheplatypus157]

BLT showed only a little throttle body leakage at 25+psi, I verified mechanical timing myself (5* BTDC), and base fuel pressure is 43 psi. I apologize as far as the maf comp not being inline with actual AFR. I only have a couple of my friend's logs and that night we were changing tons of things and testing to see if anything affected the way it ran. We tried leaning out the powerband, richening it, and changing the global to see what the injectors worked best with. The issue is, he claims they're 1000s even though they're imprinted 1250s. I think that's besides the point right now though because it doesn't matter what injectors are in it, it still has that stutter. Right now, I'm not looking so much as to calibrate the computer with the car as far as air and fuel go, but I'm just looking for any ideas as to what the stutter may be. I was thinking something electrical. Maybe loose CAS wire connection, poor power transistor, or faulty ground at some point?

 

[AWD-Tony]

Can you post a video of it doing it? And possible note the time in the log?

 

[perrytheplatypus157]

The video doesn't show or sound like much is going on. Also ignore the fact that its running rich on WOT. It was just an experiment that didn't change much of anything. The video starts around the 325 second mark in the log. If you look, youll see the rpm in the log spike. It seems to affect RPM, Airflow, MAF, and injector duty cycle (and anything that bases its calculations off of those). It also doesn't feel like a normal misfire. I've felt lean misfires, poor spark misfires, blown out spark, but this more like the car grounds itself out and shuts down for a fraction of a second. Doesn't matter the load. Basically, if you just take a glance at the log and see all of those blips, we're trying to figure out what they are.

You must be logged in to view this image or video.

 

[pauleyman]

BLT showed only a little throttle body leakage at 25+psi, I verified mechanical timing myself (5* BTDC), and base fuel pressure is 43 psi. I apologize as far as the maf comp not being inline with actual AFR. I only have a couple of my friend's logs and that night we were changing tons of things and testing to see if anything affected the way it ran. We tried leaning out the powerband, richening it, and changing the global to see what the injectors worked best with. The issue is, he claims they're 1000s even though they're imprinted 1250s. I think that's besides the point right now though because it doesn't matter what injectors are in it, it still has that stutter. Right now, I'm not looking so much as to calibrate the computer with the car as far as air and fuel go, but I'm just looking for any ideas as to what the stutter may be. I was thinking something electrical. Maybe loose CAS wire connection, poor power transistor, or faulty ground at some point?

Verifying 5 btdc is not how you check mechanical timing. Did you actually take the covers off and check the marks?