Stang is driving my crazy I need to take it to a shop

[Turbo92PGT]

Long story short. My car idles high all the ****ing time. I cant stand it anymore. I have replaced the IAC (have 4 or 5 to swap between), even purchased a brand new one. No help. Replaced the TPS, bought a new IAT sensor and tested the ohms with my stock ford sensor. Same, so that tested good.

TPS voltage is set at .97 (.96-.99 ok i heard).

I start the car up, it will begin to idle at 1200, then slowly climb to 1500. Then after a good 30 seconds idling at 1500 it will cut out and nearly die. Then stabilize at 900. Then after a couple seconds will idle at 1200 again.

While driving I let off the gas to find the car not engine braking at all but rather speeding up slightly. So I push in the clutch and the rpm's begin to climb.

With my "dyno tune" my rpms on the freeway will hang at 4000RPM.

I put it back to stock tune and it doesn't hang at 4,000 but will hang just the same.

I am located in auburn. I need to take my car to a shop and have it diagnosed. I cant deal with this anymore. If I cant fix it I will sell the car, im so fed up with it.


Throttle body is stock, plenum is stock, engine is a stock 99 PI 4.6 with crower stage 2 cams. Fuel filter is new, plugs are new, wires and coil packs are new, O2 sensors are new.

Throttle body is not sticking

 

[Turbo92PGT]

recently threw codes for P1504, P0500, P0113

 

[Launchpad]

I just had a high idle this week after installing a new H/C/I combo.

Try this, follow it step by step, especially the tps reset and the batt disconnect.

Good luck

How to set the Idle RPM on '86-'95 Ford EFI.
This is information on how to set your idle rpm. This covers year models 1986-1993, and 1994-1995. This information is from various sources, like my experience, AFM, the Ford Fuel Injection Book, other site members experiences.

Note if you have an auto trans then you need to set the idle with the car in drive.

Note if you insist on using the idle control ON with the PMS, then you need to go into the PMS and set the idle control ON before setting the idle rpm. Also, you should set the air bypass to 66%, the idle rpm in the pms to 700rpm (the lowest), and the idle timing to +15* as preliminary settings, before actually setting the idle rpm at the throttle body. These are suggestions, each car will vary.

'86-'93

1. The car must be at operating temps. If you can't keep it idling, drive it until it reaches full water temp.
2. Turn ON the headlights.
3. Turn OFF any accessories, like a/c, heater, defrost.
4. Unplug the IAC connector. The IAC is the small cylinder attached to the throttle body.

Note: If you unplug the IAC and the engine stalls, then you know the TB was not open enough causing an over rich condition. Leave everything as is, just open-up the throttle screw a bunch so that the engine can breathe while you set the idle rpm. Restart the car, and continue with #5 below:

5. Adjust the throttle stop screw until you have the idle rpm you desire.
6. Plug the IAC connector back in.
7. Recheck the TPS voltage, since you may have changed the throttle blade position.

Make sure the TPS is right

The TPS is another issue. Generally, you want to try and get it as close to 0.97-0.98 at idle as possible. Make sure that when you open the throttle all the way it hits 4.60 volts. Now, with the advent of the 04 PMS, you can "fudge" with those numbers. If you cannot get the TPS to read under 1.00, for example, you can set the PMS to tell the EEC it is seeing idle at 1.01. You should always try to get the idle reading below 0.99, but if you cannot, then this feature is really useful. The same is true for WOT, you can use the TPS option in the PMS to set the WOT tps voltage. Say you cannot get it to read 4.6, or you want earlier WOT tuning to take effect. Then you can set the WOT to say, 4.0 volts at 30% error. There are more detailed threads on this.

 

[wythors]

Take it to Brad's. Brian or Scott should be able to fix you right up.

 

[VR4]

p1504 is IAC ckt malfunction
p0500 is VSS
p0113 is IAT ckt high input (unplugged or break in the wire)


i had an 07 focus kick my ass doing the same thing youre describing. p1504 being thrown IIRC and it turned out to be a bad TB.


i just checked my hotline contact history and its not there anymore. sorry i cant help more.