Just got KOEO codes for the Bronco

21 Cooling Temperature sensor out of specified range or ECT out of range
22 Manifold Absolute Pressure (MAP) or BARO Sensor out of range
24 Intake Air Charge Temperature (ACT, IAT) sensor or Vane Air Temperature (VAT) sensor out of range

Can someone tell me what now?
Any help is great!

Original Posting:
I bought a 89 FORD Bronco 5.0 EFI Auto. May of 2005. I drove it for about six months. The only problems were a bad starter relay (replaced it), the tranny would clunk at 35 mph when speeding up, would clunk going into gear, and the blower motor was stuck on low. Then she just stopped running. Now she sits upon her throne in the driveway awaiting a rebirth.

She doesn't want to turn over, and when she does, she idles low and rough(chugs), then stalls out.

Now nothing.

Replaced fuel filter, checked fuel shut off... thats ok, new spark plugs, spark plug wires...

At a lost. I worked on cars from the 70's, but nothing with EFI, or sensors, or computers.

Where do I start?

 

Since you can't really perform the KOEO test properly the best you can get is "close". The codes you listed are indicative of the engine being too cold when the KOEO test was administered rather than any real problem with some internal system. Since, however, you cant' get it started to run til its at op. temp. its gonna be difficult to be certain. The KOEO and KOER tests should be administered with the engine at normal op. temp. In your particular situation thats not really possible.

You say it "just stopped running". Did it die on you or just wouldn't start one day? Can you hear the fuel pump prime when you turn the key "on"? If so, do a pressure check at the schrader valve on the fuel rail. If she wants to start and will occassionally fire but run rough, I'd be looking towards a fuel-delivery issue. Maybe a bad FPR or a clogged filter.

 

The truck was running fine on my way home from work one night. Then "bam" she started puttering out. I nursed her home as best as I could. After that I couldn't keep her running, or if she did finally stay running, she would idle low and rough.

 

Your 89 has TWO fuel pumps. One in the tank (low pressure) and one on the frame rail (high pressure). Either could be the culprit. As I mentioned, the FPR (Fuel Pressure Regulator) could be the problem as well. The fuel filter may be clogged. The symptoms would lead one to believe the problem is fuel-delivery related rather than spark or induction-related. Obviously of the throttle cable has broken or something obvious like that, then all of these ideas go right out the window.

To check the fuel pressure at the fuel rail, you will need a fuel pressure gauge that you can attach to the fuel rail at the schrader (tire stem type) valve. Normal pressure at the rail with KOEO is 35-45 psi. There are specific tests for checking the volumetric efficiency of dying electric pumps but when they fail they usually just quit.

The symptoms youlist are more indicative of a fuel-delivery problem than anything but until some initial checks are performed nothing should be ruled out.

 

I took some pictures of what may be problem.

http://home.earthlink.net/~badlaw187/

Thank all very much!

 

Ok, the cable with the green arrow in photo #1 that has the break marked with a blue circle should be connected to the vacuum diaphram circled in yellow in photo #2. With this cable broken its highly unlikely that your cruise control functions properly. The diaphram maintains a certain amount of pull on the cable when the cruise control is engaged which in turn mantains the necessary throttle position to maintain the selected speed. With a break just behind the cable stay, as pictured, its unlikely the cable moves properly. The cable with the orange tip (red arrow) is the TV cable for your transmission. (Dictates the gear, i.e. 1st, 2nd etc., that the transmission is in based on the throttle position). The other cable (blue arrow) is the throttle cable that runs to the accelerator pedal.

Photo #3 shows the open end of the Thermactor fresh air pump (smog pump) intake filter (green arrow). The flexible metal hose across from it was probably connected to it at one time. It doesn't really do anything but extend the intake plumbing for the pump out into the passenger side fender. Reconnect it if you want... it's not gonna hurt anything the way it is. Might want to give a look into the end of the filter and see how filthy it is. Consider replacement if its really nasty.

 

OK, heres where I am now.

Fuel pumps are powering, engine cranks but will not fire. You can smell gas at the engine.

I am thinking distributor issue now.

Thanks!

 

OOps! I meant to ask a question, not make a statement with my last post.

With the engine not firing, is the distributor is issue?

 

Could be... Could also be a failed/failing ICM (Ignition Control Module, also referred to as the TFI module) which is more likely. If you aren't sure, you can remove the SPOUT connector and see if the truck will turn over with it removed. If the truck fires up and runs, replace the module.

 

I replaced the MAP sensor, and bam, the truck works now. That was the last part I part I checked/replaced!