rough idle 1986
Thread Starter
Melting Slicks
Joined: Oct 2004
Posts: 2,283
Likes: 0
From: Leeds Alabama
rough idle 1986
replaced coil,plugs,wires,module,cap,rotor,fuel pump / clean fuel tank on car I just bought - was non running for a year due to a vats issue.. Checked all injectors .....17.5 to 18 ohms each...good. Car cranked and run fine EXCEPT rough idle...cleaned throttle body and iac. Get a code 44 ....lean. clear recheck code 44. Car is up to temp.....02 readout shows zero BUT its in open loop.....will NOT go into closed look regardless of coolant temp NOW when I shut the engine off, I instantly get an 02 reading of avg. 482. . either way, closed or open, shouldnt have rough idle. Even though ohms were good, judging by the fuel tank, I am going to replace injectors? Any thoughts?
thx
thx
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
If the O2 sensor voltage does not move or is sluggish, I might would replace it after going through the motions. The ECM is in open loop until certain conditions are met. There are timers that go off, coolant temp ~140ish, exhaust temp 600ish. The engine will start in open loop no matter how hot the engine is. For a lean signal I would check fuel pressure, should be adiquate. Exhaust leaks before the O2 sensor in the drivers side exhaust. Vacuum leaks is another. Use a FSM to troubleshoot the code 44. Could be connections and/or wiring causing the problem.
Thread Starter
Melting Slicks
Joined: Oct 2004
Posts: 2,283
Likes: 0
From: Leeds Alabama
thx...found two totally in/op fuel injectors...spent tonight pulling the plenum and runners and fuel rail....what a pain!!!!!!! There MUST be some special tools I dont have to get the hex bolts on the bottom of the runners? I also found some vacuum lines broken. Still havent figured out how to get the hex bolt from the far side of the egr valve out yet.
I'll post update this weekend.
I'll post update this weekend.
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
corvette1989bham: I was able to remove the fuel rails and injectors on my 89 without pulling the runners from the intake. Howerver, the plenum had to be removed. Removing the runners from the intake is a real bitch!
