Won't Idle

[Bruce M]

1993 3,2L ATX (p)

Won't idle after 60K service. Changed the following gaskets, valve, intake, TB, IAB, EGR.

Idled but ruff before all this had oil in plug ports, bad wires and plugs. Now She runs nice when you throttle it by hand, hold it at 800 or so very smooth. Tested for vacuum around all ports and hoses, useing carb cleaner, could see no draw or increase/decrease in idle. Blocked intake with clean rag and a rubber membrain, cranked over for a second watched the menbrain pull into the rags becuase of the intake vacuum, could hear very very slight hiss like a pin hole in a tire tube that after a good minute would release the menbrain. not a high volume leak. Traced to it to where EGR vacuum reg hose goes into intake. Cleaned and replaced, no moere leak at all. Still no idle, IAB measures 9.5 ohms, book says thats good. Checked wire to and from MAF, TBS, IAB, all ring out with meter.

Had TB screw turned in a bit for other tests but it is back to factory set point. would run nice with screw tuned in a bout two turns but that would cause other problmes

any sugestions, do I just replace the IAB?

any help welcome.

 

[mccrash]

i wound say u got a vac leak.recheck the line going in the intake.one on the back side,but if that was the one it wound be sucking lots of air.

 

[SHOtime2511]

spray carb cleaner down where the intake meets the heads,if the RPMs change then you've found the problem.

 

[Bruce M]

RE: Vac leak

As I said in the first thread. I have ruled out Vac leak. did a comp[lete check.

 

[SHOtime2511]

it would help i i read the whole post first huh? HAHA!!
have you checked the codes?

 

[Bruce M]

Re: Won't idel

Yes I did pull the codes and they are listed below with comments. The 411 might be that I had the TB screw turned in so I could keep the car running for other tests, The computer might have been unable to get a low idel controll.The TB screw is back to factory set. Never had a MAF fault untill now. Car did idle before I did the 60K stuff (see earlier thread) but was very ruff, oil filled up the plug wells, bad wires and plugs.


KOEO = 157 - MAF sensor circuit below ciruit voltage range. Does anyone have an easy test for MAF. This MAF was with the car never saw this DTC.

KOER = 411 - Cannot controll RPM during KOER low RPM check. What is the cause of this IAB maybe? if so is the test of 7 - 13 ohms across pins a good one? Again this IAB was with the car, no DTC untill now.

 

[Mr95Gl]

I'd swap out the IAB with a new, or known good one just to rule it out. I had the same problem where the car would start, idle fine for a couple of seconds, then flat line.

 

[Bruce M]

Problem solved

No idle turned out to be the IAB, I put a new one in just this morning runs and idles nice and smooth. I tested that thing in every way that ford & chilton show and they all pointed to it being OK. Highway test showed that EGR problem gone, clogged intake and bad EGR Vac switch fixed tha.

New problem surfaced; CEI came on again, now for TC 177 front O2 sensor. Reset and will run for a while before I swap that out.

Thank