Changed to in tank pump, lean issue/stumble
Hey All,
Finally changed to an in tank pump non-pwm so the pump setting is set to 100.
Off idle seems to be going lean, hits 17-20 and then recovers. Does this pretty often now. Under a heavy acceleration it's fine and my idle is pulsing till its warm or I give it some gas, records a 76 fault for a bit in the log but clears. Fuel flow and Fuel Pump shows 99 all the way threw.
Using a Holley EFI replacement setup no external regulator. Have Hydro-Mat in the tank then a 100 Micron and then a 10 up front just even wondering with the in tank if I need the 10...
Any thoughts would be appreciated.
Definately need the 10 micron.
What is your fuel pressure? Really need to see a datalog to help with lean condition.
Trying to dig up my gauge for FP now... I did notice my IAC steps at idle are way high... They where at 8.. guess I need to start there.
Here is a link to the log:
https://www.dropbox.com/s/3bi73k9frdipses/Basic%20Sensors2.csv?dl=0
I run my IAC steps around 15.
Try clearing your Learn or reload the default cal file. Wouldn't hurt to reflash, ECU programmer, the unit. May have some corrupted software.
Your learns are all over the place. This could be from a previous learn with different fuel pressure. We definately want to make sure you are at 58 psi at idle and vacuum off regulator. Unless 400 unit or Meanstreet, 43psi.
I reset my learn after I put the pump in and re-loaded the base calibration last night just after that log, going to fix my IAC tonight. I think the pump its self is only a 60PSI pump, Walbro 255
OK.. re-did my IAC and got it down to 8-10... One thing was weird.. When I screwed in the screw just little bit like an 1/8th of turn after getting it to 8 it jumps up to the 40s... Wonder if the IAC controller is on the way out or there is something else going on
Word of wisdom. With fuel injection, the IAC steps you see is the commanded value by the ECU, not the other way around. There is something else going on if the ECU is commanding odd steps.
Yup.. It's only after the fuel pump swap that this started of course the could be coincidental waiting on FP gauge just to double check it. Never had the IAC steps jump up when screwing the adjustment in... Called Fitech of course they said Vac leak, I just checked for vac leaks and did not find anything. It's been on the car for years without issue. This is what I get for messing with something that really did not need to be messed with.
Ok.. I figured out the IAC thing... When I first got the FiTech there was no Disable the TPS step... Forgot all about that. Once I disabled it was able to get the IAC steps down.
Still need to go for another ride...
Quote from kcarlasc on July 8, 2019, 1:17 pmOk.. I figured out the IAC thing... When I first got the FiTech there was no Disable the TPS step... Forgot all about that. Once I disabled it was able to get the IAC steps down.
Still need to go for another ride...
Hey, were you able to figure out the issue after the pump swap? having a similar issue on a 400 Pontiac with the same fuel system change.