I've got no spark! cant figure it out! arrrggghhhh

[stackz]

EDIT: FIXED!! I've got no spark! cant figure it out!

EDIT: turns out 4 of my five edis modules are bad. tossed the very last on one and it fired right up and runs great.

ok, truck ran when parked to pull down in order to replace a cracked head. I pulled it down, replaced the head, and put it back together. now I have fuel but no spark at all.

I've checked my harness plugs to make sure everything was hooked up and it is all hooked up.

I replaced the fuses and the ecu with 2 spares I had and nothing.

I then replaced the coil pack with a known good one (even though mine WAS good) and I got a single quick spark from the plug I had sitting on the cowl when I cranked the engine over and then nothing.

I dont know? I'm at a loss.

I'm thinking about taking the engine harness out and testing the wires but I dont know how effective this will be since I dont have a diagram of the harness to go by.

anyone have any ideas??

The only codes I could pull were 21 and 24 and I think it gave me those since the other ecu's I tried haven't actually been able to crank up and run yet. If the ecu spits codes at me, it's good right??

 

[MrShorty]

21 and 24, especially if the engine won't start, are almost certainly a result of the engine being cold. It gave you a pass code in the memory codes?

 

[stackz]

yeah, I got a pass code from memory but that's only because while I had the truck torn apart I had the battery out so the ecu reset and I havent been able to get it to crank or anything etc.

I just get my "11" for the CM.

I wish someone has the wiring diagram for the engine harness on a 91 explorer so I'm not feeling around in the dark on the harness tonight when I take it out to do a continuity test on all the wires...

 

[MrShorty]

If you try to start it, and the no start is something the computer can see (such as fuel pump, bad CKP, etc.), it usually still leaves a code in memory.

Have you tried the wiring diagrams at www.autozone.com?

 

[stackz]

you mean subscribe to their alldata service?? I'll pass. I have mitchel on demand but my new pc doesn't have a 3.5" floppy drive in it. I guess since nobody has the diagrams or can share them I just need to go buy a floppy drive for $10 real quick so I can actually install the program.

 

[MrShorty]

Their Vehicle repair guides are an electronic version of a Chiltons DIY manual, which you can access for free and has wiring diagrams in it. However, if you already have access to Mitchell, and a $10 disc drive will allow you to access their wiring diagram, I think you'll be better off. Chiltons wiring diagrams are often adequate, but they are far from complete.

 

[TPLYNCH]

How good are your battery cables? Have you rechecked your negative connection?

 

[lonestar]

I had the same prob before. Wouldn't start, then a few hours later it started right up, never figured it out. The only thing I could figure (from searching the forum) was a faulty crank position sensor. Try tapping the CPS with a screwdriver a few times and see if it starts. Its right up front under the crankshaft pulley.

 

[stackz]

I was reading the electrical system diagnostic on their site, I take it I can get both an EDIS diagnostic cable and neon spark tester at autozone??