I wondered when I saw the username mouse53. I figured there weren't too many mouse fans with Hardbody trucks. lolOK How do I check the fuel pressure on my 91 D21 with 4cyl 5speed standard? I have the pressure check set, but don't see the connector anywhere on the fuel rail.
Hey JP2code I'm also 1madmouse on Infamous Nissan, just looking everywhere.
Several things that could cause misfires:Thanks, smj999smj, I did end up using a T where the fuel filter is and did get about 36psi running, so probably not the pump. Used a stethoscope to check the injectors and they are all clicking, so they are working. Now to find why the stutter or miss, it's not the plugs, rotor, or cap, they are new. Going to replace the vacuum lines and the plug wires today. The only code I got was 55 so running out of options.
At this point it may be wise to perform a compression check on every cylinder looking for a weak cylinder; compression pressure: standard - 192 psi, minimum - 142 psi, difference limit between cylinders - 14 psi. If you find a cylinder out of spec, a valve may be sticking or seating improperly. You can follow up with a leak-down test to try to pin-point the cause.Ok after all the new parts and much scratching of my head , it runs a tiny bit better, but not right. Still have a small miss at take off sometimes and you can feel the at idle it goes back and forth, miss then clear up. I did replace all the injectors with new ones, checked all the sensors and replaced any vacuum lines that looked bad or marginal, set timing at 12 and cleaned the MAFF , new O2 sensor, it was giving fluctuating readings, and intake thermo sensor which wasn't working at all. I know I checked IAC valve and it read right, but maybe should remove and clean. Also have read some about the check valve in the pump not working right, but the pump is new. I think I am about out of ideas here. Before the fuel pump went out this truck ran nice for over 6-7 years, now something isn't right.