Help..Howell EFI Idles High?

[Gasman303]

My 83 Jeep CJ7 AMC 258 i6 / 4.2l 6cylinder 5 speed is idling at 1,900 RPM with idle adjustment screw backed all the way out to where the screw isn't making any contact with the throttle arm?

I didn't see any other adjustment screw on the throttle linkage or throttle body? Could this be something else like vacume or timing too far advanced?

Other than that the Jeep runs excellent but is high revving!! any suggestions would be appreciated

 

[Scooter402]

I wouldn't think it would be your timing causing it to idle that high...if it were, it would be very hard to start.

I'd be looking for either a vacuum leak (search around spraying carb cleaner. If the idle goes even higher, you've found your leak), or an idle air control valve. Is there one on your throttle body? It may be stuck open.

 

[Gasman303]

Tried starting it again and it idled perfect at around 7-8000 rpm but after a few minuets it died and wouldn't start after waiting 3 minuets it started right up and idled fine again... IDK what else to check, I'll start with carb cleaner on vacumm lines, thanks

 

[Gasman303]

So i tried the carb cleaner and no high idle, but i did notice when i sprayed the O2 sencer or below it (exhaust collector) the jeep would die?

 

[Scooter402]

So i tried the carb cleaner and no high idle, but i did notice when i sprayed the O2 sencer or below it (exhaust collector) the jeep would die?

That's odd...a leak there wouldn't cause any idle issues...you'd just hear a ticking or buzzing sound. If there was a fault with the O2 sensor, it would trip the check engine light. With it being somewhat erratic with the idle after starting, and sometimes dying, I would think it would still be an IAC (idle air control) motor issue. Some EFI systems have a way you can set the IAC stepper. Do you have any instructions with yours? I can see if I can find anything if that will help.

 

[Gasman303]

That's odd...a leak there wouldn't cause any idle issues...you'd just hear a ticking or buzzing sound. If there was a fault with the O2 sensor, it would trip the check engine light. With it being somewhat erratic with the idle after starting, and sometimes dying, I would think it would still be an IAC (idle air control) motor issue. Some EFI systems have a way you can set the IAC stepper. Do you have any instructions with yours? I can see if I can find anything if that will help.

I do not have any instructions for this setup. The problem I'm having now is the jeep won't stay running, the idle ramps up for a few seconds then drops down and dies? It then floods with gas and becomes difficult to start back up. After waiting for a few minuets I can get it started and running but same thing happens. My inline fuel pressure is at 13 psi

I have been reading forums for the last 2 hours and found the TACH FILTER which is inline on the howell wiring harness before the ECM is a common problem. I'm going to call howell tomorrow