4.0 v6 no spark - EDIS6? coil pack (condenser)? crank position sensor? What is wrong?

[jond9001]

Hello people,

I drove my old 1990 ranger out of the yard the other day, took pictures of it, then posted it on craigslist. The ad has generated a lot of interest, and I have had roughly 15 people call about it in 4 days. Today, the truck wont start. It didn't have spark at first, then all of a sudden it did start; after warm, I shut it off and now it wont start.

Years back, it did this same thing to me. I went to the junkyard, got an EDIS6 module, changed it, and bingo... the truck ran fine. Today I did the same thing. I also got a coil pack. I changed them both and the truck still wont run. I cleaned all of the mounts to make sure that everything was grounding, and still nothing.

Has anybody had this issue before and diagnosed the problem. Could it be the condenser on the side of the coil bracket? The ignition switch? The crank position sensor?

 

[Earl43P]

Have you conclusively determined that it doesn't have spark when it won't start?

It could be the fuel pump, FP relay or PCM relay. Will it run on starter fluid sprayed in the intake? Then it has spark and not fuel.

Just because it did something years ago doesn't mean it's the same problem. See if there is fuel pressure at the schraeder vale on the fuel rail.


http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Ignition1990_4_0.JPG

http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Enginecontrols4_0_3_0_1of3.JPG

 

[jond9001]

Earl,

Thanks for the response, but I have concluded that it is getting fuel. Fuel pressure is adequate at 40-48psi when cranking. Ether will not start the truck. I have a spark tester inline which shows no spark. In case the spark tester was failing, I also used an old plug grounded to the engine.

I have been reading all afternoon about the edis6 system. Supposedly, the system is standalone, and consists of the edis module, crankshaft variable reluctor wheel, crank position sensor, and the coil pack. From an article that I just read, as long as the edis is getting power (doesn't even need to have the ecu plugged in) then it will adequately provide spark to the engine. If this is the case, then I need only check the crankshaft position sensor, the edis (already changed it), and the coil pack (already changed it).

My issue is that I only have this one source of data about the edis system. I could definitely use some more insight about it, so if anybody knows about it, please give me your two cents.

Jon

 

[Snoranger]

I'm looking at a wiring diagram for a 94 4.0 EDIS6 module, but it should be the same. Maybe it will help some.

Pin#1 --- PIP signal
Pin#2 --- IDM
Pin#3 --- SpOut
Pin#4 --- Ign Ground
Pin#5 --- CKP-
Pin#6 --- CKP+
Pin#7 --- Shielding ground
Pin#8 --- Bat +
Pin#9 --- Ground
Pin#10 --- Coil "A" (Neg)
Pin#11 --- Coil "B" (Neg)
Pin#12 --- Coil "C" (Neg)

 

[jond9001]

Thanks to those of you who provided schematics and diagrams. I used these to test that I was getting 12v at the EDIS module and the coil. After testing that, I tested continuity from the edis to the coil, then from the edis to the computer, then from the coil to the crank sensor. All wires tested good.

This left me with three components to look at... the EDIS module, coil pack, and crank sensor. According to some information that I read about the system, the engine will fire with these three things, then it will bring the computer in to control timing. I had the trucks original EDIS and two extras from the junkyard, so I ruled that out. I tested the coil pack (and an extra from the junkyard), and they seemed to be right out of spec (according to clymer or haynes manual). I had people telling me that it had to be the crank sensor, but for $40 at the parts store, I hated to be wrong.

I bought it anyways- bolted it up, plugged it in, and the truck started up! I sold the truck last week.

 

[84bluebronco2]

Sad that you sold it, but fantastic that you fixed it and kept a level head with a proper thought process while doing it! Go buy another one and fix'er up nice! Sounds like you could handle a project.