Won't Idol (Page 1/2)
Notamechanic NOV 05, 02:07 PM
85 2.8

Posted a while back and I thought the problem was bad balancer wasn't keeping time. So I changed the timing chain and the balancer but it seems to have changed nothing. Car runs and sounds fine under constant throttle, just refuses to idol.

No vaccumm leaks detected, ioc is new.

Does the ecm need reset? I know they need to learn how to idol and I've done a lot of work and have only took it for one drive but not far from the house since the idol issue could leave me stranded.

[This message has been edited by Notamechanic (edited 11-05-2022).]

Patrick NOV 05, 05:06 PM

quote
Originally posted by Notamechanic:

need to learn how to idol



This should be a good start!




quote
Originally posted by Notamechanic:

ioc is new



I assume you mean IAC. Did you have it retracted before you installed it into the throttle body? If not, it's possible it got jammed into the orifice.
theogre NOV 05, 08:28 PM

quote
Originally posted by Notamechanic:
Does the ecm need reset?

ECM will Reset IAC when you drive > 35 MPH
If you haven't driven then ECM has not Reset the IAC and have to guess the IAC Steps to set Idle.

Some engines in some years also reset the IAC when Park and sees RPM > 2200-2500 when you push the gas pedal. 87-88 Fiero L4 can so this.

If a sensor etc change happens w/o battery disconnected then ECM often have bad data and may think IAC is Reset but isn't and have same problem until drive > 35 MPH.

Even when scan tool said IAC Reset Yes/True... I think ECM will reset this at some point to make sure IAC didn't miss a Step or more and mess up Steps Count thus screw up idle.
Notamechanic NOV 06, 11:23 AM
Pulled out the new IAC (that is what ment, sorry).
Pushed in the the tip a little and re installed. Didn't change anything.

Went ahead and took it on a 6 or 7 mile round trip on some dirt roads. Had too ride the brake and throttle to slow down without dying around corners.

That didn't seem to do much. It died in the driveway when I got home.

Checked out the flashing codes but it only showed 12 which is the diagnostic mode code. So no real codes to read.

Gall757 NOV 06, 11:54 AM
Auto Transmission? Disconnect the TCC and test drive again.
Notamechanic NOV 06, 12:57 PM
I will check the TCC next. Thanks!

Went to check the TPS for voltage and got nothing. I found a broken wire leading into the TPS. Ordered a new TPS and pigtail. Will replace those and go from there.

Need this turd running by the 19th. Just need it to make a 10 mile round trip without dying. I want to it to drive the Fiance and I away from our ceremony. Wish me luck.
cam-a-lot NOV 06, 06:27 PM
Patrick! Don't be soo cruel! Canadians can't spell either. If you want proper grammar/spelling, it is best to check in with a recent immigrant. I am sure you cringed at the recent Cadillac "Break" conversion title as much as I did...

Idle is for cars. Idol is for White Wedding,., baby! one of the best songs in decades!
Patrick NOV 06, 06:47 PM

quote
Originally posted by cam-a-lot:

Patrick! Don't be soo cruel!



...



Notamechanic NOV 11, 10:46 AM
Got the wires and TPS fixed and still no luck. Started to suspect fuel pump or maybe regulator? Previous owner put a new pump in shortly before I bought the car.

When key turns to on, the pressure shoots up to 45 psi then drops immediately. Down to zero within a minute while key is still on.

When the car starts it maintains the 45 psi then settles down to around 40. Dropping to 35 if revved. Then the second my foot comes off the gas the car dies while psi maintains around 40. Then drops a second or so after the engine shuts off.
Patrick NOV 11, 03:22 PM

quote
Originally posted by Notamechanic:

When key turns to on, the pressure shoots up to 45 psi then drops immediately. Down to zero within a minute while key is still on.



That information is critical. There's obviously a fuel pressure leak somewhere. Could be in the tank (where the pump connects to the hard fuel line), could be the fuel pressure regulator diaphragm, could be one or more fuel injectors.