friends sho running bad...help?

[dabeast25]

93 atx car has been very quick for what he has done....this is what he's done.....k.n cold air induction very open exhaust and a ted b lpn
he was running great and went on a trip to vegas
on the way there he got some 87 gas....which he has done before on road trips....with no problems
right before vegas he got 87 again at a truck stop...and the car had no bottom end balls...ran below avrage im the mid range (but not as bad as the bottom end) and would not rpm past 5800...and had very little power...he found 108 octane and put that in his tank....and it got alittle better but didn't have the performance when he got that gas at the truck stop!
after a few tanks of gas on the way home....it was getting better and back to normal
then at a differant truck stop and his last fill up be for he was home ....it started actting the weird again....and now he has a tank of this crappy gas and his car runs like crap....has anyone had this experience before and is this how it would act if he had water in his gas?
we checked fuel preasure at the rail and it was fine ....no code at all...and the air fuel gauge is running a little lean across the board......and in my car it does run a little leaner than normal when oi run 87 vs super or better...i think it is becaus e the computer backs of timming when it pings under 87...and gives full timing under super or better......and we cheaked everything we could think of....even plugs wires ...water in the plug wells ....and nothing ....is thisvery wierd....2 truck stops thousands of miles away could have bad gas??? and is the way the sho will act with it?....and what does he do now???? thanks
p.s. racing at acto nj this weekend for the idrc event....please other sho's come out.....thanks

 

[93nighthawk]

It is possible that he got bad gas from truck stops. Personally I do not get gas at truck stops, because the majority of fuel they sell is disel, not gas, so who knows how old it is. It just seems to odd and does not point to any other problem that I can think of.

Eric

 

[dabeast25]

well i cant figure it out....just went out and tested fuel preasure and while the car is cold...and at idle it is between 25 and 30 psi and goes up with the rpms to about 45....but when the car heats up the preasure drops from45 to about 25 ...and the drop acures at 4000 rpms....that i don't think is normal...i think the preasure should rise with the rpms and sustain at the max preasure ....and that should be around 40 to 45 psi......but what i though was weird....was when i disconected the preasure regulator....it stayed at 40 ....no matter what rpms i was at.......so i don't think it's the fuel pump...because how could it stay at 40 when the reg was unplugged???
we just took the car out to get cigs....cold it runs alright ...not like it was ans the air fuel gauge showed alittle richer......warmed up the gauge slowly went to real lean side...and it ran like crap....and won't get passed 5k rpms.......could this be streaching timming belt and has 140 k with out the belt changed........things that make you go hhmmmmm