Idle problem, Really Rich

littleboylan

Registered User
Alright guys, as some of you may have read in the MEMBERS ONLY section. I have been fighting an idle issue for sometime now. Everyone keeps saying its a vaccuum leak. Well I pressurized the system today to find only 1 leak. I fix that and now that car is a little bit better with IAC plugged back in.

Now the only codes I am pulling is a 225, (knock not sensed during Dynamic throttle response). I dont think this has anything to do with it.

Im assuming that an airleak in the intake would cause me to have a lean condition. Well my air/fuel meter stays pegged on the RICH side. Anyone know what this could mean??? And yes the gauge is hooked up correctly as it worked fine prior to my idle problems.

Any help will be appreciated Thanks Mike
 
I think I may have the same problem as you. When you start it, it will stall instantly unless you give it a lot of gas. My car is running really rich too, you can smell the fumes in the air. The Rpms will shoot up and down. How did you pressurize the system to find the vacuum leaks? Because, that is what everyone says the problem with my car is. Did you check the TPS and cam sensors?
 
iac

I pressurized the system by screwing in a quick connect air hose piece right into my mp inlet plenum then sprayed all connections with a soap/water mix.

Well I ohmed out the IAC and it read 11 ohms, I measured the TPS and it read .92 volts. I have not checked the cam sensor yet.

I DONT have to give it gas to idle, on initial startup it goes up to about 1500 then slowly falls back down. The whole time it is running really rich.

I am wondering if maybe my fuel pressure regulator is going out, but I have about 35psi at idle and gos up consistently with boost. When I shut the car off the boost gauge needle takes about 4 seconds to go back to zero. I dont know if this info will help anyone better diagnose my problem.

I even double checked the plug wires making sure the were all hooked up correctly. Which they are.

Thinking Im going to just take it to the dealership this weekend and see if they can figure it out right now Im stumped and if I dont get it figured out, this v6 challenge at Milan this weekend wont be an option.

Mike
 
Mike - if your idle starts at 1500rpm then slowly drops back to normal, I would have to say your IAB/C valve is sticking open. Generally speaking vacuum leaks cause a rough or unstable idle.
 
Iac

I have been thinking it has something to do with it. When it is unplugged the car runs much better and the idle is down around 900. When the car starts to warm up, even with it unplugged, the idle will be more around 12 or 1300 rpms.

I know my o2s are good, I just recently changed them, over the winter.

Thanks for the hints/tips Mike
 
littleboylan said:
I have been thinking it has something to do with it. When it is unplugged the car runs much better and the idle is down around 900. When the car starts to warm up, even with it unplugged, the idle will be more around 12 or 1300 rpms.

I know my o2s are good, I just recently changed them, over the winter.

Thanks for the hints/tips Mike

My base bird used to shoot up to 2000 rpm as soon as you start it.... it was the IAC. Replaced it and haven't seen that again in about 6 months.
 
If the O2s are good, the IAC would be my guess. I sprayed mine with carb cleaner and messe it up and it did the same thing with high idle and then drop down. The one from Ford ain't cheap, but I've heard it's the best one to get.
 
Sensors

Well I am going to be getting some used sensors, to swap out with the ones on my car to see if it makes a difference. I would really like to be sure before I spend $105 on a new IAC from my Ford stealership. Seems Kinda high.

If I ever figure this out I will be sure to let you all know. Thanks again for all the tips. Mike
 
littleboylan said:
Well I am going to be getting some used sensors, to swap out with the ones on my car to see if it makes a difference. I would really like to be sure before I spend $105 on a new IAC from my Ford stealership. Seems Kinda high.

If I ever figure this out I will be sure to let you all know. Thanks again for all the tips. Mike

Yeah it ran me about 95$ from the local parts house. :)
 
Fuel Pump

I know its not the fuel pump, In december I installed the 255 lph Hi-Flo Walboro Unit. Like previously posted my fuel gauge I have installed on the fuel rail, is reading consistant with specs. Im still at a loss, this weekend my g/f's dads going to check it out, hes a master mechanic. Im sure between the two of us hunting we might be able to find something. see ya Mike
 
How do you have your A/F meter hooked up? I ask because it seems strange that your car could be running so rich and idling so high. It would seem to indicate that either your meter is lying or you have a really really big air leak. If you were getting normal amounts of air and still running rich, I would expect it to idle very low or almost die.

Also, you should check your ECT if you haven't already. The computer enriches the mixture for cold starts.
 
air/fuel Gauge

My Air/Fuel gauge is hooked up through my computer wires, eec pin #43, Its drivers o2 only. It only idles rich, under normal driving it sweeps across the gauge normally, It is a weird problem.

Ill have to check the ECT, is there a way to test it??
 
littleboylan said:
My Air/Fuel gauge is hooked up through my computer wires, eec pin #43, Its drivers o2 only. It only idles rich, under normal driving it sweeps across the gauge normally, It is a weird problem.

Ill have to check the ECT, is there a way to test it??

I think thats normal... I know my friend had a A/F guage on his 5.0 mustang and it showed rich at an idle. My old LTD was supposed to be set a little rich on the carb too. :confused:
 
air fuel

Well guys, today Im driving the car, and I look at the air/fuel gauge, and to my realiziation, it IS NOT running rich, but running stoich, right were it should be, when I floor it, it goes to rich. Normal, if you ask me.

Anyways, I have been driving the car now for a few weeks, very little, with the IAC unplugged. Well I also noticed today, that my idle is still high even with it unplugged, like 1300 rpms. When I first start the car and drive for the first 5 minutes it will idle at like 900. It seems to after it warms up the rpms stick up a lot higher than when cold???!!! Does this mean anything to anyone? Thanks Mike
 
To no luck

Well today I swapped out, IAC, BaP, DIS, and nothing I did had any effect on my idle. So as of right now I am still STUMPED.

I have zero codes, all I get is 111 for both KOEO and KOER tests. Im not too sure were to go from here. Looks like this is a dealership only repair as I have tried everything I can. Thanks for all your help you have gave me. Mike
 
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