Memphetic
15+ Year Contributor
- 115
- 3
- Nov 6, 2005
-
Punxsutawney,
Pennsylvania
'92 GVR4. I put 720's on it and an EPROM chip I burned. Was running great. I put a wideband in place of the narrowband set on simulation mode and hooked it to the ecu. A couple days later, it starts running lean under boost and rich at cruise. I immediately think "air leak prior to turbocharger between MAF and turbo". I check for leaks in the intake pipe... none. So, I think, must be the fuel pressure regulator being overrun (it's an Airtek E2448, aka a Walbro 284 in a $45 box), and swap it with the one from my VR4 and set the fuel pressure to 43.5psi. I test it up to 90psi, no leaks. Solves nothing.
I go to Advance and swap the pump out for a new one in their parking lot because it takes 3 tools and 10 minutes... solves nothing.
I replace the fuel filter with a brand new one... solves nothing.
I hotwire the pump to receive constant voltage and it solves nothing.
I think maybe my fuel injectors are clogged (all of them? ??), so I swap them back out for stock 450's and drop the fuel pressure to 36psi. I also remove the ECU, because that may be a culprit, and replace it with a stock non-EPROM. Solves nothing.
Also tried replacing the resistor pack with a known good one, as well as the MAF sensor. Solved nothing.
Driving around on 17:1 AFR's right now, and if you hit boost or go over 30% throttle it fuel cuts immediately
I go to Advance and swap the pump out for a new one in their parking lot because it takes 3 tools and 10 minutes... solves nothing.
I replace the fuel filter with a brand new one... solves nothing.
I hotwire the pump to receive constant voltage and it solves nothing.
I think maybe my fuel injectors are clogged (all of them? ??), so I swap them back out for stock 450's and drop the fuel pressure to 36psi. I also remove the ECU, because that may be a culprit, and replace it with a stock non-EPROM. Solves nothing.
Also tried replacing the resistor pack with a known good one, as well as the MAF sensor. Solved nothing.
Driving around on 17:1 AFR's right now, and if you hit boost or go over 30% throttle it fuel cuts immediately