Running Lean
Thread Starter
Instructor
Joined: Nov 2007
Posts: 108
Likes: 0
From: Waukesha WI
Running Lean
Hey all, quick question regarding a lean condition on an 85. I've replaced the fuel pump as a tech checked it over and said that it was bleeding off fuel pressure and told me to replace the pump. Car still runs like *** and is clearly running lean (pops thru the intake, exhaust tone sounds like it's constantly missing). What other things would cause a lean condtion like this? I've tried disconnecting the battery to allow the ECM to reset itself. How common is it for a fuel pressure regulator to go bad? And if i understand correctly, the regulator is on the return side of the injection system so i would clamp off the return line at the pump and then pressurize the system and check for bleed off right? Any help would be great.
Thread Starter
Instructor
Joined: Nov 2007
Posts: 108
Likes: 0
From: Waukesha WI
Well, here's the deal. Put a fuel pressure gauge on it and turned on the ignition. Instantly went to 30psi. Started it up and it went up to 35psi and would go up with I would rev. the engine up. Shut it down and the pressure was still at 30psi 15 min after it was shut off. So with that info, i'm assuming it's not a fuel pressure issue as it seems to have the proper pressure while running and it's not bleeding off anywhere. What would be the next step?
