92 exploder 4.0

[Kenter]

I got a new used ICM from the pick and pull got it tested and it passed. I plugged it in and it worked for about half an hour. Then started hesitating when I would accelerate. As soon as it was hesitating under acceleration it would keep missing until it died. It acts as though it's run out of gas it's got over a half of a tank. The battery has been real weak. So I thought if I redo the battery cables and see if that does anything to no avail. I took the ICM and got it tested again and it passed. What else could it be?

 

[Duane867]

Check fuel pressure, spark ( good white blue spark ), and proper air flow.
If you have all three then we can start trouble shooting the rest.
You really need to do a self diagnostics test or have it scanned and get the codes as well.

 

[Kenter]

No spark, air is buen, fuel pressure is buen. It hasn't got a check engine light on to check for codes. That and it isn't running to get it to a place to check it.

 

[Duane867]

Check your coil packs, the Crank shaft position sensor and the trigger wheel behind the crank pulley for missing teeth ( the CPS reads off of that ). 1st check the cap and rotor, as well as plug wires.

This is how you test the ICM and the coil packs with a simple test light. The directions are what I wrote up for a 2.3L for a fella earlier that had no spark but they should be the same for any Ford motor.

Remove the coil pack connector.
Touch the ground lead of the test light to the positive post of the battery. Then crank the engine over ( have an assistant do this ) and touch each wire in the coil connector with the positive lead of the test light. The red wire has to have power at all times from the ignition when the key is on and the light on the test light should remain solid. I believe you will see a flashing light on all the other wires if the coil is being sent the correct signal. This test should rule out the ICM and a couple other items as bad parts. It would point to a bad coil if you get a blinking light on all wires but the red. The red should remain solid.

If there are no blinking lights then you need to test the ICM with the test light in a similar fashion. You will leave the ICM connector plugged up and gently stick a paper clip in the harness side of the ICM connector. As before leave the negative lead of the test light touching the batteries positive post and have an assistant crank it over while you touch coil3 and coil4 wires ( those are spark plug 3 and spark plug 4 on the drivers side ) on the harness side of the ICM connector. If you get a blinking light the ICM is good. No light and the ICM is bad. Leave the harness at the coil disconnected while you test the ICM harness.
If the ICM is good then I would suspect a bad cam shaft position sensor, missing teeth on the trigger wheel behind the crank, crank shaft position sensor, PCM, or the ICM or PCM wiring.
I posted the info above for a guy who had problems getting spark to the intake side but the same rules should apply.

 

[Kenter]

ANy other ideas? Th ICM tested good the coil is good CPS tested good wheel behind crank is in good condition no missing teeth. Still no spark getting to be real frustrating.

 

[Duane867]

Your crank position sensor checked out good ? How did you test it ?
How about the cam shaft position sensor ?

 

[Kenter]

according to the testing sheet I got from work it say's the CPS can be tested through the ICM wiring. It is working within the parameters.

 

[Duane867]

That makes sense. It sends cylinder identification to the PCM and ICM.
Since you have tested the CPS I would test the cam shaft position sensor.
I think all it does is provide the injector pulse signal based on cam position but its worth a shot.

You have a 3 wire CMP.
Black with white stripe wire is the ground.
Red is the CMP signal return wire to the PCM.
Dark brown with orange stripe is the CMP connection wire from the PCM.
( I may have the DB/O and the red wires backwards. Hopefully some one who knows for sure will chime in )

The following was taken from a Ford explorer enthusiast website regarding a 2001 explorer 4.0l CMP test. It could be different but its all I could find that didn't invlove a special CMP testing harness. Its still a 3 wire connector so I would think its that same testing methods......

The connector on the CMP sensor has a CMP connection and a SIG RTN connection. With the rounded part of the connector to the left the CMP is PCM Pin 85 is on the top, SIG RTN PCM pin 76 bottom.
Test Steps:
Check for open cmp, sig rtn/cmp gnd and pwr gnd circuits between pcm and cmp sensor.
This is the continuity check? Should be less than 5.0 Ohms, Yes

Then:
Check CMP circuit for short to power in harness by:
Reconnect CMP sensor
Key on, engine off
Measure voltage between CMP and CMP GND/SIG RTN circuits at the PCM connector.
Is voltage less than 1.0 volt? If no repair short circuit in harness

If yes then:
Check CMP circuit for short to GND and SIG RTN in harness by:
Diconnect CMP sensor
Measure resistance between CMP and CMP GND/SIG RTN at the PCM harness connector
Is the resistance greater than 10,000 Ohms? If no, repair shor circuit

If yes then Check for shorts in PCM by:
Reconnect PCM
Measure resistance between CMP and CMP GND/SIG RTN circuits at the CMP harness connector.
Is the resistance greater than 500 Ohms? If no, Replace PCM

If yes then Check CMP sensor output by
Reconnect CMP sensor
Digital Multimeter on AC scale for less than 5.0 volts
Measure voltage between CMP and CMP GND.SIG RTN circuits while running engine at varying rpm.
Does the AC voltage varey greater than 0.1 volt AC? If no Replace CMP sensor.
If yes replace PCM.

When you tested the Coils you got a solid light on the red wire, and blinking lights on all others right ?
Same for the ICM ?

 

[AllanD]

Your crank position sensor checked out good ? How did you test it ?
How about the cam shaft position sensor ?

There is no cam position sensor on a 1990-93 4.0 Engine.

1994 is the first year they had them and even then not all 94's did

AD

 

[Duane867]

Oh shit. I looked up a 92' and my software shows it ?


EDIT.. Oh I see what I did there. California model OHV 4 liters with SFI have the CMP and all other OHV 4 liters those years have a CPK sensor only ( crank shaft position sensor).

Thank's for pointing that out.

 

[Kenter]

Anything else? I replaced the ICM for craps and giggles to no avail, still no spark...

 

[Duane867]

Are you absolutely positive you tested the crank sensor correctly ?
Aside form a bad ICM or coil what your describing ( since your missing a CMP ) is a bad crank sensor. I dont want to tell you to go and buy one only to have the same issue but...

 

[Kenter]

I'm sure that its good. Here is the procedure that my Haynes manual told me to perform in order to determine whats what:

Check the resistance of the CKP on terminals 5 and 6 of the ICM. It should be between 2000 and 3000 Ohms if it isn't check the Crankshaft position sensor.

It was right at 3000 Ohms so it is good... The motors have a timing chain instead of a belt right? If that had broke it would be making a horrible noise while trying to start it correct?

 

[Duane867]

Yes. Timing chain. You would think it would make some noise when cranking, unless the chain some how isn't rubbing the crank gear if its broken. Which I doubt. They usually do not go bad. Chain and gear sets can sometimes go well over 250k and look like new in 4.0's.

BTW, all you did with that ohms test was confirm the wiring had no breaks leading to and from the CPK. Ohms measures the resistance in the wiring to the part only.
All you know by that test is that the wiring is able to carry the current soundly.

What you want to measure is the electrical current that either is or is not being passed through the sensor as the gap closes over the sweet spot when the crank rotates. You test the CPK with a digital multimeter set to AC volts and back probing through the ICM on the pins your Haynes manual told you to. If your not able to there then you remove the connector from the CKP and hook the leads up there. Then have some one crank the engine over. Watch the multimeter and look for readings no less then .5v and no more then 1v ( that's the voltage test specs for a 3.0L. should be the same for a 4 liter as well ). I'll do some checking and try to get the exact voltages it should stay between.

My money is still on a bad CPK.

 

[AllanD]

Ahhh... how about using FORD standard acronyms.

OR spelling out the names of what you are talking about

I have NO IDEA what you guys are talking about because you are in essence using made up words.

Acceptable terms:
The main computer is "PCM" Powertrain Control Module or "EEC"
CPS Crank Position Sensor
The ignition Module is "EDIS-Module"

Do not use names made up by Haynes or Chiltons

If we don't speak the same language communication is all but impossible and diagnosing and problems solving become... well completely impossible...

BTW, the cam position sensor (if so equipped) has NOTHING WHAT SO EVER to do with the ignition system

You only need concern yourself with the crank Sensor, the EDIS Module, the coil pack and the wiring between them.

AD