1998 Ls1 fuel pump???
1998 Ls1 fuel pump??? You mentioned 58psi of fuel pressure. Was this at idle or under WOT load in gear? Sometimes a fuel pump will show excellent pressure sitting at idle, or even free-revving, but under load is a different story. So if loaded fuel pressure has not been checked, then I would suggest that as one thing to look at.
Do you have a comprehensive OBD scanner? If so, I'd want to look at LTFTs (long term fuel trims), KR (knock retard) and total timing at WOT.
Since you already tried unplugging the MAF, and swapping it, and changing the front O2s, all without a permanent improvement in power, and that it randomly ran perfect for a 15 mile period, the above diagnostic information would be my next step if it were mine.
Do you have a comprehensive OBD scanner? If so, I'd want to look at LTFTs (long term fuel trims), KR (knock retard) and total timing at WOT.
Since you already tried unplugging the MAF, and swapping it, and changing the front O2s, all without a permanent improvement in power, and that it randomly ran perfect for a 15 mile period, the above diagnostic information would be my next step if it were mine.
Recap of events since Friday
I checked the fuel pressure which read right at 58 lbs. Cleaned the MAF and had good results for a couple of miles, and then back to sluggish car at high rpm..This lead us to believe possible oil from the K&N filter was getting on MAF. Switched to a paper filter recleaned the MAF and still the results were the same sluggish. . Next changed plugs, wires and upstream o2's. Car ran like a Cadillac at idle and low rpm. High rpm sluggish, per like a v6 or worse.....
Today rechecked fuel pressure at prime, idle and WOT under load here are the results!!!!!
Prime--- 0 lbs to 30 lbs and back down to 0 lbs
start engine --- 0 lbs to 26 lbs car starts.....
Idle--- 29 lbs
WOT under load---- 20 lbs
Root Cause of issues Fuel Pump... is there a fuel regulator that I need to change or anything else???? While I'm upgrading fuel pump.... Recommendations for a quality fuel pump looking at the racetronix system and harnesss???
Do I need to buy a new fuel pump assembly????
The fuel regulator is located on the fuel pump assembly, but I have read other people experienceng failure with the component the regulator plugs into. GM does not sell this part...
I would lIke to upgrade to the racetronix pump and harness , but think I will still have issues..
This link is to a thread almost exact issue I have aND part description
https://ls1tech.com/forums/fueling-i...98-camaro.html
Problem solved.....
https://ls1tech.com/forums/general-m...ower-loss.html
https://ls1tech.com/forums/general-m...ower-loss.html
Last edited by M-Z28; Dec 13, 2014 at 01:29 AM. Reason: update
