DTC code 28

[jrubot]

It`s a 91 Ranger and computer with a 96 motor.
The haynes book I have doesn`t even show code 28, so what is the IDM- ignition diagnostic monitor, and how can I stop the code.
I got a bunch of codes fixed,but need a little help with this one. Don`t have a clue.
I`ve changed both coils out.
Any help appreciated, I would really like to get this thing running in a closed loop.


Thanks

 

[martin]

If you look in the tech library of this site it has a list of computer codes. It list 28 as vat. vane air temperature sensor.

 

[jrubot]

28 Vane Air Temperature (VAT) sensor out of range - VAT
2.3L w/Electronic Ignition - Cyl ID, IDM low or right coil pack failure - Ignition Systems

And the line below that? How does IDM get low? Cause I`ve swapped out Coils and Spark plug wires with no success

 

[jrubot]

From what I`ve read Tach and IDM are on pin 2 of the EDIS6 which I am guessing is an ICM. It looks different than mine. Mine has a harness connector Top and bottom EDIS6 illustration I saw only 1.
Starting to make sense because Tach stopped working awhile back, I guess I`ll try to trace down My Tach wire anyone Know the color code for the Tach on a 91??

 

[jrubot]

Thought I would update ICM tested bad waiting for 1 from ebay.

I found SPOUT connector, I need to put a timing light on it because I did a crankshaft sensor mod on this motor. OK I was looking at wires near the air cleaner and I notice what looks like a SPOUT connector right below the Self Test connectors. Can anyone tell what this is??

I update again after ICM arrives

 

[Bryan22]

91 ranger with 96 motor... so you used the crank sensor from the 91 and just modified the 96 block to accept it? Or are you trying to use the 96 sensors with the 91 computer?

 

[jrubot]

I mounted the 91 sensor to 96 block and changed the pulley from the 91. It ran good until i blew the head gasket and it sat up for awhile.
Igot a bunch of codes when I first got it running. Worked thru em all then started getting 28 (IDM loss) and 33(EGR) got EGR to go away and blocked it off with Sheet Metal.
Thought it was ICM(since it tested bad) Got it yesterday,Ran good,,, no OK at first then started backfiring and wouldn`t run.
I`m going to try to get it started today and check it with a timing light with SPOUT unplugged.
I am starting to think CKP(crankshaft position sensor) has gone bad too.
Any help or suggestions appreciated

 

[Bryan22]

That code sounds like either the CKP is bad, the new coil pack is bad, or you've got a problem with the wiring somewhere in between. I know that's kind of a vague answer, but sounds like you're on the right track. I'd start with checking the wiring and all connections at the ICM and coil pack and grounds. Also check that the crank sensor is sending a signal with a multimeter. I don't know what kind of voltage it's supposed to return, but I'd asume you should see it send some voltage back in correlation with the rotation of the crank, if that makes sense.

Another guy had a problem with his ignition system on here recently, turned out to be a wire pulled part way out of one of the connectors at the coil pack.

also the 91 ignition system is DIS not EDIS.

 

[jrubot]

Thanks
Yea I know it is DIS, Just never found a picture or wiring Diagram.
I was hoping the new ICM would get my tach working again,but no such luck.

 

[jrubot]

OK did KOEO and got 14 and 28
It is very hard to get started and had NO luck getting it started with SPOUT disconnected.
Guess I`ll try starting with 1 coil disconnected at a time see if 1 is bad and try to backprobe my CKP next