CLASS RACER FORUM - View Single Post - GM 4l80e trans vibration in O/D when towing

rognelson777 · 04-14-2013, 09:27 PM

Update, New plugs, wires,distributor cap, rotor and problem is gone. I OHM'd all the old wires and plugs and all matched the new wires and plugs.

I guess something was breaking down under full load.

Used over the weekend towing in virginia and all is well. Other crew members could not believe the difference.

side note, when checking fuel pressure at idle, it may be low, so give it a little rpm and it should come up to spec range of 54 to 57psi. Mine was 47 at idle but as soon as I touched gas pedal went to 54psi and stayed there, even under load.

thanks, class racer

04-14-2013, 09:27 PM	#7
rognelson777 Member Join Date: Dec 2010 Posts: 372 Likes: 20 Liked 132 Times in 72 Posts	Re: GM 4l80e trans vibration in O/D when towing Update, New plugs, wires,distributor cap, rotor and problem is gone. I OHM'd all the old wires and plugs and all matched the new wires and plugs. I guess something was breaking down under full load. Used over the weekend towing in virginia and all is well. Other crew members could not believe the difference. side note, when checking fuel pressure at idle, it may be low, so give it a little rpm and it should come up to spec range of 54 to 57psi. Mine was 47 at idle but as soon as I touched gas pedal went to 54psi and stayed there, even under load. thanks, class racer Last edited by rognelson777; 04-14-2013 at 09:30 PM.