Glassman's car

[cjsgarage]

Hey y'all. Maybe some of you have some more support for this issue. Finally got the car running sweet-exhaust solved many issues. I was up late last night repinning the harness and flashing an F-Body computer to run the Camaro. Runs great. Lack of traction in forward gears. Just great. Except it won't do a donut. Mike's a pretty tolerany guy (not sure who's garage it spends more time in..) but for the money I'd think it should show off from time to time. But it won't. Deleted all the torque management and running nearly the same tune I'm running in another car that does donuts perfectly. I can't think of what I'm missing. Last I checked, lateral g's don't turn coils off and don't affect compression numbers. Must be fuel. I called Spectra on the tank (GM42AFI) and they say there's no roll-over valve or anything else that shuts off. They suggested starvation, but this is a on/off feel. Not a stutter. Ideas?


maybe PTaddict will pick this up: Do you think the 85mm MAF tuning could be the issue? I'm not losing stoich, and it'll rip tires loose in straight lines or in sweeping corners. Just not tight circles. It's the only major difference between this tune and another car I did not too long ago. I haven't tried reinstalling the 78mm as it would require cutting the immaculate harness I slaved over. (running HPTuners with a 2001 FBody ECU now)

[Vince@Meanstreets]

Cj,

What does it do when you try to whip it? Stall out, sputter, back fire or just goes straight?

[cjsgarage]

stalls out. If you push the clutch soon enough you can save it from full stall. But it's like someone flips the off switch when it sees the car swing. I thought it was the "undeletable" traction control on the GTO computer, but that doesn't seem to be the case

[cjsgarage]

Cj,

What does it do when you try to whip it? Stall out, sputter, back fire or just goes straight?
I guess a more thorough answer would help.

It does not go straight. Suspension is killer and alignment is right on. It's trying, just won't keep em spinning. Gets halfway through the arc and shuts down.

It does not sputter to a stop. It goes from 4500RPM to dead. No back fires. I tried posting a thread in HP Tuners, too, just in case. I just don't think it's the tune. Truthfully, I'm ready to take this tank out and fabricate one. Or drop a pump I can vouch for in. But I was hoping someone else running the Spectra stuff could chime in with a similar experience or the fact that they've had no problems doing smoky circles with their Spectra EFI tank.

[Z06vette]

How much fuel is in the tank? If its half tank or less it could be starving. Especially if its an older version. Just my experience with some of the ones I ran in the past.
Scott

[glassman]

Scott, its a brand new tank, we're thinking the fuel pump may not be enough?

to be continued.....

[cjsgarage]

yep. Definitely got fuel in the tank. Furthermore, the Spectra set up is baffled. Mike and I have been thinking to pull it down and put a pump not made by Spectra in there. I'm thinking Spectra cheaped out on the pump. Maybe after I replace the pump, I'll fill it up. Better than to fill it up before I drop the tank :yes:

[Z06vette]

Its baffled but not much of a baffle. Its just a generic pan- like a baking pan sort of. The ones I have use an AC delco pump. The newer ones have a better baffle than the old ones but still will starve at less than half tank in "donut" or high g corner. What are you using for regulator? I would think if it were a pump problem your straight line accel would be affected in the same way. Let us know what you find out. Scott

[WSSix]

plumb a fuel gauge into the fuel rails or run a wide ban O2 while doing the donuts. That should be able to tell your if fuel supply is the issue.

If the symptoms are occurring instantly and repeatedly in the same manner, it's more than likely not fuel supply. I'd lean towards ECM. Loss of fuel will most likely stutter and not be instant and not be consistent in it's occurrence.

[glassman]

When i watched the data log timeline unfold before, it could go either way. Yes, we were going to run a fuel guage in the rail, but dont have a fitting the size for my afterrmarket rail. Programming the computer is absolutly amazing to me, i'm learning alot. Alot more to learn when u have problems.....

[cjsgarage]

Bad fuel pump. If I can figure out how to post the video, you can see it dropping down to 20. Or below. I was a little preoccupied with driving to be exact.


http://youtu.be/9NsnFdl6wzo

[Sieg]

Hope it's that simple! :thumbsup:

If there is a starvation condition occurring.......I'm assuming fuel pressure would drop when starving?

[cjsgarage]

Hope it's that simple! :thumbsup:

If there is a starvation condition occurring.......I'm assuming fuel pressure would drop when starving?

It is. If you check the video, it's a youtube of the pressure dropping out.

[Sieg]

It is. If you check the video, it's a youtube of the pressure dropping out.

I watched it fall and wondered if it there was a low fuel condition in the tank and under hard forward acceleration could it have created starvation?

Just playing devil's advocate.......like I said I hope it's as simple as a bad pump.

[glassman]

Everything I've read so far regarding these pumps indicate that there not really high performance, so up we go. Drives great though. But I will doing more than just driving it around....I have a health condition called "rightfootdown" disease ....and the only cure is a fuel pump that pumps