Recent fuel issue at upper RPMs

Castillo817

Castillo817

Greenie N00B Member
Greenie Member
I am on my 5th revision with Justin and earlier in the week when doing datalogs, I felt something weird around upper 5k RPM all the way to redline. Like if the car was kind of hesitating. I was really thinking it was a map issue since I have not had a problem with the previous maps.
On Monday night whenever I sent the logs, I did noticed high knock at upper RPMs and running lean. I never took a look at the HPFP since I really didn't think it was that until today whenever Justin emailed back saying I'm having a fuel issue. I have about 10k miles on these AT HPFP internals (bought new). He mentioned could be relief valve or in tank fuel pump.
I attached 4 of 8 logs that I took.
 

Attachments

I would pull the internals out and inspect them, and also pull the spill valve and inspect that. Check for any gunk buildup, etc.

I suspect your in tank pump is bad as Justin suggested, since the problem shows up in the top end where you are flowing the most fuel. Luckily this is not too bad of a job on the Gen2 MS3. You simply remove the rear seat, cut a larger access hole, unscrew the top of the fuel tank (there are philips head screws holding it on), take off the fuel line and electrical connections, and pull the whole unit out. The biggest problem is that those damn pumps are like $125.
 
VTMongoose said:
I would pull the internals out and inspect them, and also pull the spill valve and inspect that. Check for any gunk buildup, etc.

I suspect your in tank pump is bad as Justin suggested, since the problem shows up in the top end where you are flowing the most fuel. Luckily this is not too bad of a job on the Gen2 MS3. You simply remove the rear seat, cut a larger access hole, unscrew the top of the fuel tank (there are philips head screws holding it on), take off the fuel line and electrical connections, and pull the whole unit out. The biggest problem is that those damn pumps are like $125.
Click to expand...
If it ever does it again, I will do what you mentioned above, thank you!
Good thing my car has been running great lately without any issues. Justin actually adjusted my upper rpm and made it bit more richer. Knock is almost gone if any on this final map we just finished.
Going to pump some e85 today :) we'll see how that goes
 
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