here is the situation, new map in a new engined car and the idle is good, but weird.

When the car warms up, the idle is at like 1600rpm, i don't have the thermowax rod anymore. everything is good but idle doesn't seem to go down.

If i put electrical load on the car (fan at settings 3 for example) idle will come down to it's normal 1000rpm. If i rev the engine a bit, it will stabilize real quick, no problem.

But if i remove the electrical load, and i rev the engine, idle will start hunting, then stabilize at 1600 and after maybe a minute it will slowwwwly come down.

So basically, my idle is perfect when i have the electrical load but not when i don't have the load.

Anyone has a clue why?

thanks a lot

 

Re-do the idle learning procedure (in the PFC manual) before you try anything else.

 

You have to verify that all idle controls are set at the appropriate positions.
(1) throttle cable
(2) throttle adjusting screw
(3) dashpot
(4) air bleed screw
(5) primary injector atomization hose
(6) no missing hoses or hose leaks
(7) no other air leaks.

 

i have checked pretty much all of those but would any of these cause the problem to be only when the electrical load is not on?

because it does eventually go back to normal but it's not as fast as when the electrical load is on it.

thanks

 

A normal idle speed of 1000 rpm is high unless you have a large port engine.
You removed the hot wax rod/fast idle cam unit, but how about the AWS?

 

yes the aws is obviously removed. I put the idle at 1000 in PFC so it is normal that it is that high. he engine is ported pretty big, it idles better at 1000. All the emission stuff was removed too.

thanks

 

Use carb cleaner to check for leaks first. spray it around the UIM, between gaskets etc. listen for the engine to bog down.

I had a big leak causeing my engine to not go below 1300 rpms. My primary injectors were leaking air cause they had no seals between the rail and block.

A higher engine load will cause the idle to drop unless the ISC is functioning properly. Try unplugging it and see if it makes a difference. maybe its stuck open or closed.

Personally i prefer the manual idle control as chuck (cewerx7r1) recommends and shows how to set up in his tuning notes.

There are alot of good threads discussing idle control setup. Search some of my posts and you can find some.

(i also have a large street port)

 

yes when i unplug the isc the idle drops, i first adjusted manually to something like 800 and replugged it with 1000 in the pfc.

i guess i will be patient and see if the pfc learns the idle over time.

 

is your air bleed screw adjusted half a turn out? you have to remove the throttle body elbow to get to it.

 

about 3/4 a turn i would say