Car bucks when accelerating, blowout?

[unclesam099]

The car bucks when I'm going WOT, and it's usually only on cold days (like today). I am around ~18-19psi on cold days.

I've hit fuel cut before, just hear a big POW! and then you can keep on driving... Well with this, I can keep my foot on it and it jerks forward like slamming the brakes for a sec, then will pick back up.

Is this blowout? I just put in NGK BPR7ES plugs, and I have stock fuel, except for a Walbro 255 hi-pressure pump. SAFC zereod out, same with the MAFT. I'm kinda new to tuning, but I am trying to learn.

 

[kelvinb]

according to your cars mods, you do not have an aftermarket fpr, do you?

 

[unclesam099]

No, no AFPR. I just updated my mod list and that all is current. Actually, I forgot to add that it's rewired.

 

[kelvinb]

any chance you have some logs to post? probly not if you didnt post any

using the stock fpr is probly not a great idea, it may have something to do with the cold weather and the fact that your fuel is being regulated irregularly..ha..

 

[unclesam099]

Reading up on a tuning post kinda points to it being fuel cut though... I dunno, I can go get some logs tomorrow and see. But like I said, it's only when it's under 32F that it does it.

 

[Talesin]

Definitely sounds like fuel cut.

And you'll want to get an AFPR ASAP... I was running the same way (prior owner didn't put on the AFPR), ended up blowing out my injectors to the point that two wouldn't close, and was running stupid-rich all over the place even on the other two. Makes it a total b***h to get a decent baseline and good tune out of it, too.

 

[unclesam099]

Yea, I haven't really seen problems with anything yet, but I will be getting an AFPR very soon. Problem is that even though it probably is overrunning the FPR at idle, there is something that's making it read lean and my low trim is pegged at 140%.

 

[1990EclipseGSX]

Sounds like fuel cut to me too. Because air is denser when it is cold, I imagine you are flowing more air on cold days. The difference in airflow could be enough to make you fuel cut only when it is cold out.

 

[BISHILVR]

Make sure you did'nt blow an intercooler pipe off.

 

[unclesam099]

Ok, I did a log today and it looks like fuel cut to me. I have IDC of 128% right before it cuts, . My airflow on the SAFC reads in excess of 2500Hz when it happens. I pulled 5% at 4k rpm and 7% at 5-7500rpm and it quit cutting.