No Spark on 1992 4.0l, need help.

[crazybronco]

I have a 1992 4.0l Auto 4x4 Ranger. It was running just fine, but we don't use it much because we got it for my son that still has about 2 months before he gets his license. I went out to start it and it will crank just fine, but not start. I pulled the air tube off before the TB and shot either in it, then put it back on. Still no start. This tells me I am not getting spark. I checked all the fuses that I could find(checked owners manual), all are good.
Due to this being a DIS system, I do't know where to go from here. What do I check next?

 

[bhawk]

You have to check for spark properly. Remove a spark plug wire and insert a spark plug of the same type. If you don't have one, you will have to remove the plug belonging to that wire. Then hold the threaded edge of spark plug that is inserted into the wire against the exhaust manifold or cylinder head and have someone turn it over. The plug should spark regularly as the engine turns over. Test at least 3 of the plug wires for spark and report back. If no spark exists at any spark plug held against the engine, you will move to other components. There is an ignition control module (ICM) on the radiator support on the passenger side. It may be faulty, or the coil pack.

 

[crazybronco]

I am used to the old distributor and coil ignition systems and have very little knowledge of the DIS. Is there a page somewhere that explains the Ford 4.0l DIS and its components?
I will go out and check for spark that way. I would have thought that if there was any spark at all I would have got a reaction from the either, at least a pop or a back fire, but I got nothing at all.

 

[BlackBII]

Is there a page somewhere that explains the Ford 4.0l DIS and its components?

http://rockledge.home.comcast.net/~rockledge/RangerPictureGallery/DIS_EDIS.htm

http://www.dainst.com/info/edis/edis.html

http://www.megamanual.com/ms2/EDIS.htm

 

[crazybronco]

BlackBII, thank you for that information, it helped a lot. I am a mechanic, but have spent the last 20 years working on mostly Diesels and Aircraft, so DIS is a little different for me.
From what I read it sounds like I lost the PIP, crankshaft Position Sensor signal. How can I check this to see if it is good or bad?
Is there a way to check codes on these older trucks?

 

[BlackBII]

http://www.therangerstation.com/tech_library/OBD_I.html

http://www.aa1car.com/library/crank_sensors.htm

http://www.aa1car.com/library/dis.htm

http://www.wellsve.com/sft503/Counterpoint3_1.pdf

http://visforvoltage.org/forum/4194-testing-hall-sensors

 

[bhawk]

Pulling any trouble codes is a must. I just learned how to do it a couple weeks ago, and it saved me big time.
Just go to the tech library on this site. Under the heading "computer" you will see an article EEC-IV Diagnostics. Read that. Basically you will make a jumper wire and and once you join two wires, your computer will make the check engine lite blink out any trouble codes. If your CEL is burnt out, then you can use a test lite or amp meter to get the codes. The article explains it pretty well. There are other articles on the web that explain a bit more, but this one is all you need.
Report back what codes you get.

 

[crazybronco]

Well, this is going to remain a mystery. I went out to check some things on the truck and see if I could look at the CPS. I turn the key and it started right up, no problem. I have now started it about 6 times and it works great. I must have wiggled a loose connection or something while checking the fuses.
All I know is it is working now.
I did learn some things along the way though, so thats good.

 

[bhawk]

I strongly recommend that you pull any codes stored in the computer. A trouble code will remain in the computer for between 20 and 40 start ups before it is removed. So, pulling the codes now will still tell you if a faulty sensor was detected in the recent past. Then you can change that sensor if it acts up again.

 

[crazybronco]

Good idea, I will do that. Thanks