97GT still pings like a bastard

[Logan2003Cobra]

Bad mass air meter?

 

[Roger_4.6_96]

It could be a number of things. I would start looking at your 9 year old fuel pump.

 

[bhuff30]

I tried a couple other things. I checked, and there is definatly no chip on the computer. I also filled up with the 90 octane (yes, it is 10% ethanol, but 10% is well within the safe limit and it hasn't caused problems with any of the other cars. I've found the 90 rating to be accurate as well) Either way with 90 the problem is pretty much gone. I ran on the G-tech a couple times, and the only rattle I could eak out of it was a the top end in 4th. Thats better than it has been ever. BTW, it showed a 15.00 at 96, but we'll see for sure friday. Thats actaully better than I expected for bone stock to the paper filter with a full tank, and some stereo stuff. Lean is mean, right?

I've thought about the problem being the fuel pump, my understanding is that like an oil pump, you either get all or nothing. The car, and thus the pump only has 110k miles on it. I've never replaced a fuel pump because it wore out, only for supplying more fuel than was expected by the factory. I can throw my fuel pressure gauge on anyway.

I still suspect the MAF. I've heard a lot of experiences from others where the maf goes bad, or just gets to dirty, causing the lean condition. However, it isn't bad enough to justify the cost of a MAF yet. I'd want to get ahold of a code scanner before doing that anyway. The code scanner I have is for EEC-IV...

Anyway, thanks for the input guys. For now, it seems to be running safely on the 90 and I still have things to check.

 

[MoatesGarage]

Sometimes fuel pumps ar all or nothing, but sometimes they're not. I had one in a Jeep that had a bad check valve so it wouldn't hold pressure but it would still pump just fine. The problem was letting off the gas felt like something was pulling you backwards. Driving on the interstate was just about embarrassing. Then we've had some that like you say just stopped. The key is to run it, and shut it off and see what the fuel pressure does. If it drops to nothing instantly that could be the problem. Just my two cents.

 

[Mike97gt]

I tried a couple other things. I checked, and there is definatly no chip on the computer. I also filled up with the 90 octane (yes, it is 10% ethanol, but 10% is well within the safe limit and it hasn't caused problems with any of the other cars. I've found the 90 rating to be accurate as well) Either way with 90 the problem is pretty much gone. I ran on the G-tech a couple times, and the only rattle I could eak out of it was a the top end in 4th. Thats better than it has been ever. BTW, it showed a 15.00 at 96, but we'll see for sure friday. Thats actaully better than I expected for bone stock to the paper filter with a full tank, and some stereo stuff. Lean is mean, right?

I've thought about the problem being the fuel pump, my understanding is that like an oil pump, you either get all or nothing. The car, and thus the pump only has 110k miles on it. I've never replaced a fuel pump because it wore out, only for supplying more fuel than was expected by the factory. I can throw my fuel pressure gauge on anyway.

I still suspect the MAF. I've heard a lot of experiences from others where the maf goes bad, or just gets to dirty, causing the lean condition. However, it isn't bad enough to justify the cost of a MAF yet. I'd want to get ahold of a code scanner before doing that anyway. The code scanner I have is for EEC-IV...

Anyway, thanks for the input guys. For now, it seems to be running safely on the 90 and I still have things to check.

no fuel pumps can go in many different ways, including having a presure drop at WOT or low overall presure.

 

[5.0's 4 ever]

I would be leaning toward the MAF. If you could find a way to get a hold of scan tool check out your BARO pid.