I'd swear I'e read about a bunch of pressure related issues to the Aeromotive A1000 Pump in past but of course did some extensive google searches today & could'nt find anything worth reading....

Took my buddies '72 Challenger to track today & spent whole day chasing fuel system around, for second week in row...

Car was just finished last year late, & has a brand new A1000 on it, dual -10 Aeromotive inline filters(one before pump, one after pump), Aeromotive bypass regulator... It's I think off top of my head, -10 feed to reg, -8 bypass return... & we have a -4 gauge line running to an external non isolated 2 5/8 Autometer fuel press gauge on cowl... 16 gallon cell...This was an Aeromotive fuel system "kit" all from Aeromotive...

Put about 45 passes on it last fall, no issues... ran straight 110 Sunoco in it until last day of year @ a test & tune.... he was almost out of 110 & we cut in like 70/30 pump gas. Ran fine, put up new best yada yada...

Over the winter unbeknownst to me, he put a bottle of Sta-bil in the fuel, while his car sat in storage for 5 months...

We took it out first T&T this year, made one pass, air was killer -800 feet below DA, & ran 10.00 @ 136? Previous best was 9.87 @ 137 @ ~+600 DA... Incrementals were hair off, but that was on the old pump gas/110/sta-bil mix.... & had a leaking tube issue in slick & only got one pass. Also trans fluid, gear lube etc were nearly stone cold (36 degree day) So did'nt think much about it...Kind of just attributed it to cold car, cold track (60 sucked), & old fuel etc.

Next week, car still off a little, air was 2100-2400 feet DA all day (felt like August, not April), we started putting fresh 112 in it (all we had, waiting on drum of Q16 to come) & as the fresh 112 got in, car went quicker every pass... I think ended up going 10.08 @ 135.50 @ 2400 DA. So it looked pretty good, but 1/8 MPH was still hair off... then next pass 2100 DA, thing smokes like a diesel... & runs 10.18 @ 134... 104 in 1/8 horrible... Fuel pressure for no reason is now @ 9.5 PSI. We had it set last year @ 7.5 PSI & it had never moved, never varied... never worried about it. Hmm, so I adjusted it, took 4 turns on the adjuster to get it back down to ~7.25-7.5 range???? that's odd.... Made 1 last pass, loses 2nd round.... 10.05 @ 136. All good... MPH in 1/8 "normal" for 2100+ DA etc. Pass looked real clean....

Went back today.... & as he was loading/unloading car, fuel pressure all over place, from 5-9... depending on when you ran pump etc.

1st pass was slow again... like 10.14 @ 134, MPH in 1/8 was off by 2 1/2 MPH looked rich, he said did not check F press... I cleaned out air bleeds, dropped jet couple sizes, F press around 6.0 in pits... 10.08? 136, I put jetting back to 90 SQ where it has been for all year, backed that up with I think a 10.05 & then a 10.02 @ 136. Incrementals all look good now? Ok first pass was a fluke??? DA today was real consistent 1650-1700 all day. So think all is good... 1st round.... 10.12 @ 134, MPH in 1/8 way down... blowing black smoke... Float levels if anything are hair low....& I've adjusted them 3 times in last 2 weeks & really saw no differences in back to back passes, fuel pressure is varying wildy. Now reading low in pits around 4-5... I turn adjuster 1 turn & back to 7...

Buy back in.... 10.10 @ 135 black smoke, gets back to pits & says the F press was 9+ in lanes/burnout & down track... I'm lost. The adjuster is now 3 turns of of where it was last year (3 turns to LOWER pressure) & press as we loaded on trailer was 9.5 PSI...

We are going to drain cell tomorrow night, clean filters & pump, tear reg apart, flush all lines & hope we find something. ???

Hard to bracket race a car that throws out a wild slow pass every once in a while. We run alt on car, & also charge battery between rounds, so bat voltage should not be an issue.... Frustrating day of head scratching....