Low fuel pressure and misfire
11-24-2017, 05:18 PM
#1
Thread Starter
Join Date: Aug 2017
Location: Florida
Posts: 38
Low fuel pressure and misfire
98 GT with 110K
So I've been having a misfire for a couple of months now. I've replaced the MAF, cleaned the TB, did a smoke test for vacuum leaks. I replaced the IACV because it was leaking. I recently replaced the plugs and wires. The car still has a misfire, especially at lighter loads (2nd gear around 2-2.5k RPM) but also in other loads too but not as intense. I have P1151 and P1150 codes as well.
I measured the fuel pressure at the rail at idle and it was 29 - 30 PSI. I believe I have a return system therefore with key on engine off the pressure was 0 PSI.
I've looked online for fuel pressure specs and I can't seem to find a definitive answer. I see people mentioning that it should be around 39 -42 at idle.
If my fuel pressure is indeed low, where should I start looking into fixing it? I believe all of the fuel delivery system components are stock as the previous owner never mentioned that he replaced anything.
So I've been having a misfire for a couple of months now. I've replaced the MAF, cleaned the TB, did a smoke test for vacuum leaks. I replaced the IACV because it was leaking. I recently replaced the plugs and wires. The car still has a misfire, especially at lighter loads (2nd gear around 2-2.5k RPM) but also in other loads too but not as intense. I have P1151 and P1150 codes as well.
I measured the fuel pressure at the rail at idle and it was 29 - 30 PSI. I believe I have a return system therefore with key on engine off the pressure was 0 PSI.
I've looked online for fuel pressure specs and I can't seem to find a definitive answer. I see people mentioning that it should be around 39 -42 at idle.
If my fuel pressure is indeed low, where should I start looking into fixing it? I believe all of the fuel delivery system components are stock as the previous owner never mentioned that he replaced anything.
Last edited by DenissK; 11-24-2017 at 06:39 PM.
