Hello guys,
My car has a E4ME carburetor. It works pretty fine.
There is only something which bothers me.
When I come to a stop (with car running for some time on OD or D), if I engage P, the idle speed rises to about 1000 rpm. I have to tap on the gas to lower it to around 750-800 rpm (still in P) before engaging again a gear.
For your information, I thought at first that it was coming from a stuck choke, so I removed it and unscrewed to the maximum the high idle speed screw.
It didn't make a difference.
The base idle speed screw (on driver side) is also unscrewed at its maximum, allowing the screw to be sufficiently in contact with the accelerator pedal lever. If I had to unscrew it more, then there will be no contact between the 2.
So is there something I should check at first ? TPS ?
It's the only "problem" I have with this carb, everything else works fine.
Thanks a lot
My car has a E4ME carburetor. It works pretty fine.
There is only something which bothers me.
When I come to a stop (with car running for some time on OD or D), if I engage P, the idle speed rises to about 1000 rpm. I have to tap on the gas to lower it to around 750-800 rpm (still in P) before engaging again a gear.
For your information, I thought at first that it was coming from a stuck choke, so I removed it and unscrewed to the maximum the high idle speed screw.
It didn't make a difference.
The base idle speed screw (on driver side) is also unscrewed at its maximum, allowing the screw to be sufficiently in contact with the accelerator pedal lever. If I had to unscrew it more, then there will be no contact between the 2.
So is there something I should check at first ? TPS ?
It's the only "problem" I have with this carb, everything else works fine.
Thanks a lot
Supreme Member
A choke not opening fully would have been my first guess. But you ruled that out.
Second would be worn out throttle shaft bushings. Try this. When the motor is "doing it" and idling high, turn it off. Without touching the throttle, start the engine again. Is the idle back down where it belongs? If so, there's a good chance your primary throttle shaft bushings are just totally shot and the throttle shaft is flopping around in there so bad it's wedging the primary throttle plates against their bores, preventing complete closing.
Second would be worn out throttle shaft bushings. Try this. When the motor is "doing it" and idling high, turn it off. Without touching the throttle, start the engine again. Is the idle back down where it belongs? If so, there's a good chance your primary throttle shaft bushings are just totally shot and the throttle shaft is flopping around in there so bad it's wedging the primary throttle plates against their bores, preventing complete closing.
From what I remember, I've never tried your second idea. I will see tomorrow and report the result here 
Worn throttle bushings can be felt as play in the throttle shaft, check by feel with the throttle partially open. You should also be able to manually close the throttle to lower the idle. If worn they can be bushed with a bushing kit available from a few on-line carb shops. Did one myself a week or so ago. Drill press in the garage comes in handy now and again.
Another potential issue is a faulty TPS that is keeping the idle bump solenoid engaged at idle. The ECM engages the throttle bump solenoid at decel but should disengage it when the TPS shows idle voltage. I do not know if this is a universal feature of all year LG4s, but it was an issue once on my 87. You can de-energize it by removing the single wire connector to test.
Another potential issue is a faulty TPS that is keeping the idle bump solenoid engaged at idle. The ECM engages the throttle bump solenoid at decel but should disengage it when the TPS shows idle voltage. I do not know if this is a universal feature of all year LG4s, but it was an issue once on my 87. You can de-energize it by removing the single wire connector to test.