evoentertainment

I had an issue with my idling/ cold start idle awhile back. It was mainly caused by the fact that I have no emission parts, and the prev owner took the BAC valve out while he was at it for some odd reason. The car used to not hold an idle during cold start unless I held the throttle down and let it warm up.

The work around is, I turned up the A/F mixture and had it run a little richer. Thus, it held an idle during cold start.

Now, I dont know what happened. I instaleld a deck (i doubt its because of this). but afterwards I couldnt hold an idle again.... I would once again have to hold the gas down to have it warm up. But now, even after the car is warm, the idle would bounce between 1200-1400. Ive done research but still no answer. -_-

any suggestions would be greatly appreciated. Thanks

evoentertainment

Anyone?!

calpatriot

The engine needs a richer air-fuel ratio when it is cold. It sounds like your idle may be too lean when cold, but you need to check that. There is a procedure in the FSM to check for closed loop operation. It says you need a special digital checker box, but you dont. A simple LED with a 510 ohm resistor connected between the center two pins of your check connector will tell you. Light on is rich; light off is lean. it ought to be rich at idle.

It also sounds like it might be a vacuum leak; that would tend to make the engine run too lean, but if that is so then in theory it should get worse when the engine is warm and the ECU goes into closed loop mode.

You might check the operation of the double throttle diaphram (if you still have one); that is something that is active when the engine is cold and not when it is warm. If it is not operating correctly, or if the vacuum line to it leaks, you might experience problems on a cold engine that go away once warm. A thermovalve on the back of the upper intake manifold cuts off vacuum to the diaphram once the engine reaches a certain temp.

The procedure to check it is in the FSM.

You might also check the operation of the fast idle system, which is supposed to keep the throttle up for you while the engine is cold. Procedure in FSM.

Also, run down their checklist for poor idle / stall when cold.

evoentertainment

Thanks for the breakdown! I also suspect I have a vaccum leak. Which is the best way to look for it? I've heard of spraying things in ur engine bay, but that sounds really dangerous. Lol let me know! Thanks!

evoentertainment

I forgot to mention, during cold starts. It starts at 2.1k idle, and holds for about 10-15 seconds. After that it just slowly dies out

CWynn5

iTrader: (9)

I believe that is normal for a cold start.

Jimmy2222

iTrader: (3)

I think normal cold start is 3 grand for 30-45 seconds then 1500 for 10-15, can't quite remember. But yeah, could be a vac leak, check here:
http://fc3spro.com/TECH/PROBLEMS/P1/ENGINE/leaksv.html
remember skimming through that last night seeing some helpful stuff.

evoentertainment

yea to my understanding its normail with AWS, but I have rtek chipped ecu which eliminates that (plus I dont have any of the components hooked up, and replaced with block off plates). and saying if it is normal, after it drops my car dies out. it doesnt HOLD an idle. any input would be greatly appreciated. Thanks in advance!

evoentertainment

Anyone?