No spark cylinder 1 and 5

[Nigelpancake]

Hi all I'm having an issue with my 91 not getting spark to cyl 1 & 5. I had seen someone else had posted about the same issue but the OP stopped replying before a solution was found.


Basically at the coil there is no spark jumping from the coil to the plug wire.

So far I have tried new coil, new plugs, and new wires. The strange thing is that this issue seemed to be caused by me taking a sharp turn... where it proceeded to shut off and start misfiring. I am thinking it is electrical. Any guidance would be appreciated before I break down and take it to my local mechanic. Thanks!

 

[Fix4Dirt]

are there any codes? im not versed in obd1, but maybe someone has experience here who can help you. then it brings me to believeing it may be a bad connection, if you go over bumps too does it do that?

 

[Josh P]

How much fuel did you have in the tank when it shut off? I've had my van shut off if I take a hard turn with little fuel in the tank. Have you verified the firing order? It is common to cross wires 5 and 6.

 

[Nigelpancake]

How much fuel did you have in the tank when it shut off? I've had my van shut off if I take a hard turn with little fuel in the tank. Have you verified the firing order? It is common to cross wires 5 and 6.

There is plenty of fuel as long as my gauge is working... I have hooked wires up according the manual. It runs but if I remove plug wires 1 & 5 from the coil while running no spark is present where the other coils all have spark. When i put new pack in it wont run at all.

 

[Nigelpancake]

N

are there any codes? im not versed in obd1, but maybe someone has experience here who can help you. then it brings me to believeing it may be a bad connection, if you go over bumps too does it do that?

No stored codes and no, bumps do not have any effect. I'm pretty much stumped but youmay be right some type of loose connection

 

[Fix4Dirt]

N

No stored codes and no, bumps do not have any effect. I'm pretty much stumped but youmay be right some type of loose connection

not too sure on this one though, whats fuel pressure? wonder if its a weak pump. that wouldnt explain the lack of spark, however

 

[Josh P]

You will need a test light. Clamp the clip to the positive side. On the coil pack, the connector with the 4 wires on it. Using spark plug wire #1 as a reference, the 3rd wire in is the signal wire for #1 & 5 coil. probe that wire with the test light. If the light does not flash while the engine is running or being cranked you either have a broken wire connection or a bad edis module.

 

[Nigelpancake]

not too sure on this one though, whats fuel pressure? wonder if its a weak pump. that wouldnt explain the lack of spark, however

You will need a test light. Clamp the clip to the positive side. On the coil pack, the connector with the 4 wires on it. Using spark plug wire #1 as a reference, the 3rd wire in is the signal wire for #1 & 5 coil. probe that wire with the test light. If the light does not flash while the engine is running or being cranked you either have a broken wire connection or a bad edis module.

 

[Nigelpancake]

Believe it or not i think I may just found the issue. Beneath the battery the wire harness coming from the ICM was rubbing. Because i am missing the battery clamp wedge lol. A black and yellow wire was exposed, according to my manual its shown being the signal wire to the coil. I'm thinking this fried the ICM. I'm going to get one from the junkyard tomorrow and will update post. It makes you realize how important every bit of the car is, all it takes is a loose battery to screw up an engine lol. Thanks for y'alls input it's much appreciated.

 

[Josh P]

I believe it. It would explain why a sharp turn killed the ignition and the miss. Battery probably shifted a little one time too many.

 

[Fix4Dirt]

thatll do it its a probable cause

 

[Nigelpancake]

thatll do it its a probable cause

I believe it. It would explain why a sharp turn killed the ignition and the miss. Battery probably shifted a little one time too many.

Managed to get to the parts yard today. Bought an ICM and installed with no change. Determined that the short on the coil at 1&5 fried the coil. Pulled a used coil and installed now I’ve got spark again. Guess it fried the new coil I had bought a few weeks ago as soon it was connected reloomed all the wiring and it’s running better now. Still wants to idle at 1500rpm with no overdrive with slight miss at idle. Thanks again for the help.

 

[Pat500]

Managed to get to the parts yard today. Bought an ICM and installed with no change. Determined that the short on the coil at 1&5 fried the coil. Pulled a used coil and installed now I’ve got spark again. Guess it fried the new coil I had bought a few weeks ago as soon it was connected reloomed all the wiring and it’s running better now. Still wants to idle at 1500rpm with no overdrive with slight miss at idle. Thanks again for the help.

Check all fuses this can cause issues