So the racecar started experiencing what we thought was a dying fuel pump (in-tank lift) and would fuel cut / starve on corners starting 45 minutes into a session during our 4th race. We could limp along for a while, but did not deliver the 1.5+ hr we had for our 2nd and 3rd races. We only burn 4-5 gph so really should be good for 2 hours with a bit left over but haven't ever hit that. The first race we had a ton of rust in the tank and clogged injectors, fuel filter, etc. but gave it a good rinse after and replace fuel filter every race. We've also replaced the in-tank pump (twice) and the primary pump. I'd chase clogged things more, if the symptoms weren't so weird.
In race #5, someone pulled off into hot pits and turned the car off, thinking it was potentially the fuel pump sock getting covered with rust - or something got hot. Then it would go two laps or so before returning. In race #6, someone tried cycling the power on and off on a straight, and it worked for a few laps before the issue returning. It would start in long sweepers, but then eventually get to most turns - fuel cut at 4000 rpm or even at 3500. We traded out the chipped 027 ECU for a spare stock one, and the problem reduced in severity - lasting longer before the starvation occurred (more so than explained by slightly lower power / better efficiency). We also tried replacing the fuel pressure regulator but didn't do the trick either. We have lots of spares so could try cap and rotor as well as wires, but have not gone that far yet to just throw parts at it since originally thought fuel pumps going out.
It seems to be electrical and possibly something heating up, or something like a capacitor - which cycling the ignition helps to reset. But we couldn't think of what it would be and maybe someone ran into this before? In one threads, some people had issues with crank position sensor vs. teeth but this is an eta so gearbox sensor. If anyone has ideas, please let me know. Thanks!
In race #5, someone pulled off into hot pits and turned the car off, thinking it was potentially the fuel pump sock getting covered with rust - or something got hot. Then it would go two laps or so before returning. In race #6, someone tried cycling the power on and off on a straight, and it worked for a few laps before the issue returning. It would start in long sweepers, but then eventually get to most turns - fuel cut at 4000 rpm or even at 3500. We traded out the chipped 027 ECU for a spare stock one, and the problem reduced in severity - lasting longer before the starvation occurred (more so than explained by slightly lower power / better efficiency). We also tried replacing the fuel pressure regulator but didn't do the trick either. We have lots of spares so could try cap and rotor as well as wires, but have not gone that far yet to just throw parts at it since originally thought fuel pumps going out.
It seems to be electrical and possibly something heating up, or something like a capacitor - which cycling the ignition helps to reset. But we couldn't think of what it would be and maybe someone ran into this before? In one threads, some people had issues with crank position sensor vs. teeth but this is an eta so gearbox sensor. If anyone has ideas, please let me know. Thanks!
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