fuel pressure gm 454 1998 motorhome

rognelson777 · 02-12-2013, 12:15 AM

Posted for transmission help on here for motorhome and need help with fuel pressure diagnostics 1998 gm 7.4l 454 8 injectors.

Checking fuel pressure today, turn on key, pressure goes to 54 then drops quickly to 49 and stays there, start cold engine 32 degrees outside and pressure goes to 50 / 51 and when you rev engine, moves 2/3 psi put under load in drive full throttle and stays same. shut off engine needle jumps for a second up then back to 49. will stay there with key of for 1/2 hour.

Do you think pressure is okay? Engine starts and runs great, just dealing with this transmission vibration towing, going to change wires, plugs and cap/rotor, but do not want to install if I have to take it all off to do other repairs

02-12-2013, 12:15 AM	#1
rognelson777 Member Join Date: Dec 2010 Posts: 376 Likes: 20 Liked 135 Times in 74 Posts	fuel pressure gm 454 1998 motorhome Posted for transmission help on here for motorhome and need help with fuel pressure diagnostics 1998 gm 7.4l 454 8 injectors. Checking fuel pressure today, turn on key, pressure goes to 54 then drops quickly to 49 and stays there, start cold engine 32 degrees outside and pressure goes to 50 / 51 and when you rev engine, moves 2/3 psi put under load in drive full throttle and stays same. shut off engine needle jumps for a second up then back to 49. will stay there with key of for 1/2 hour. Do you think pressure is okay? Engine starts and runs great, just dealing with this transmission vibration towing, going to change wires, plugs and cap/rotor, but do not want to install if I have to take it all off to do other repairs