Also, i did log o2 volts today as well, at the 3500 mark when the car stalls out, the 02 sensor drops to 0 volts, but Im unsure if its the sensor making the ecu cutting the fuel, or if something else is cutting the fuel and im just seeing the 02 sensor reading it?? lol

 

Are you sure your fuel pump and FPR are in good working order?

 

I havnt actually checked those yet, but after the cutout at 3500, the car runs fine, holds 41psi, afrs are fine. I would think if it was a pump or fpr issue it would really act up in the higher rpms

 

How bad does it cut out? You may be having a harmonics issue that can be caused by big injectors and an aftermarket FPR. You may need a fuel pulse damper, like what radium offers.

 

the fuel completely cuts out, so the motor stalls a few times, then it returns to normal shortly after. what would I have changed to need a pulse damper though?

 

Nevermind. The harmonics issue just causes a lean spot (like 16-17:1) and hesitation. The engine doesn't really die.

It's an issue that can arise out of nowhere, it's a harmonic/resonance issue created by big injectors and an aftermarket FPR. It's not always present. Some cars do it, some don't.

 

Time to check the fuel pump relay. Perhaps swap with a friend just to check it out.

 

Yea, this causes the wb to lean all the way out to not reading anything for a few seconds.

The way I made my harness last year, my fuel pump relay is actually inside the cab. I can hear it click on. With the fuel pump relay, I would think when the car cuts out I would hear it clicking irratically or something?? Plus the car has no lean issues at wot after the 3500rpm hiccup

 

Are you able to log the car? See if anything is doing something funny, like you're getting a huge spike in load, which cause the ECU to hit the fuel cut load limit. This would point to a bad map sensor. Log IPW, load, MAP, timing, TPS, RPM, AFR, and Mivec/cam angle stuff.

 

I certainly can try. I did swap out a map sensor with my buddies and it didnt improve. I will log it and see how it goes. I need to get my hands on a copy of excel so I can view th logs myself lol. Right now I am sending them to a buddy to view lol.

I appreciate the help! Nothing worse than trying to figure out a pesky issue like this in the heart of racing season!

 

Well,I didnt see anything funny logging the things previously mentioned. I even swapped out the sparkplugs, no change of course.

I ordered another o2 sensor, should have it on thursday. My afrs are all over the place at idle. Sometimes it will run so rich it wants to die. Then on the opposite end, sometimes it will run so lean it wants to die. Ive drove the car around 12 miles since I had it running the last few weeks and its went through 3/8 of a tank at least lol.

Im really hoping the o2 sensor straightens it out.

 

new o2 sensor went in yesterday, no change yet again. I am gonna snag a new GM ait snesor today and put it in see if anything changes.

 

lean spool disabled?

 

I can check. Nothing was changed in the tune over the winter though.

 

Bump for any help!