E4ME Idle Adjustment

[Tim81]

I just finished my engine rebuild and trying to get everything tuned. The engine runs great when its first started up cold, nice fast idle and very smooth. After the choke opens and the carb comes off of fast idle it acts as if the idle is set too low. There is a idle adjustment screw on the driver side of the carb that I can raise the idle speed with, but it was my understanding that the CCC controls the idle speed and I should leave the idle screw alone. My question is can I adjust the base idle speed with the idle screw? Once I get the idle correct I'll move on to the M/C Sol. dwell. Thanks Tim

 

[Peer81]

Idle speed isn't controlled by the CCC. On later E4ME versions it is but not on ours. But I would say, connect the dwell meter when idling in park then you can see if the mixture is to lean or rich, this will also have an impact in idle quality.

Greetings Peter

 

[Tim81]

Thanks Peter,

I checked the dwell today and found that no matter where I turn the air bleed screw it stays the same. I intentionally did not rebuild the car because before the rebuild it was operating correctly. I wanted to make sure I had a decent carb for the cam break-in. I believe I may have caused the problem by converting over to a heated O2 sensor and now I'm pulling a code 44 which indicates a lean condition. I'm going to go back to the original O2 sensor and see if that makes a different.

Thanks Tim

 

[Barry08]

Tim

What is your timing set at?
Try 12 degrees btdc, if idle is still too low adjust idle speed screw.



Barry

 

[Tim81]

Live and Learn, I put the old O2 sensor back in tonight and guess what problem seems to be solved. Was able to set the dwell right between 25 and 35. The engine is idling much better, still has just a bit of a ruff idle but its alway done that, I will rebuild the carb after I have some fun driving it a little bit. Barry08 my timing is set at 12 BTDC, I love the color of your car, looks great. Thanks Guys Tim

 

[GerryLP]

Since it is difficult to quantify the left over idle roughness in our engines across Internet boundaries, all that you and I can do is try to improve the reliability in one's car.

One trick I learned, I learned from the folks at DUI distributors. You either buy their nylon screws for holding the rotor in the HEI distributors at $4.50 each, or go to Home Depot and buy some nylon screws at $0.75 for the same purpose.

Next time you replace the ignition wires, consider the 300ohm/foot Acel wires. They reduce misfires and arching considerably.

And like we have been discussing here at different times, tune that air valve to get you the best performance. I get my best results by turning the valve 1/8 of a turn at a time and allowing the dwell meter to reflect the change before adjusting it again.

 

[RC81]

Also remember after adjusting idle to reset tps voltage. It changes every time you set the idle screw.

 

[Peer81]

Weird your heated O2 sensor isn't working. Does it get hot when it's on? Mine works fine (the last time I had it in...)

Greetings Peter

 

[Tim81]

Weird your heated O2 sensor isn't working. Does it get hot when it's on? Mine works fine (the last time I had it in...)

Greetings Peter

Yes it was getting warm, for some reason the ccc didn't like it. Its a Bosch 3 wire universal sensor, there might be something wrong with the sensor itself. Was glad the old sensor still worked or I might of been chasing this problem for awhile. Tim