no spark?

[brickhousen]

1990, 4.0l has intermittant spark and does not want to start but once it does it runs fine untill i shut it off and it is realy hard to start back up and near impossible when it sits overnight, it has new coil, crank pos. sens, ign. switch,ign. module, it also has an ignition kill alarm on it but i dont think thats the problem because im pretty sure it just maks the starter not engage not positive tho. if someone could help me out it wouldbe great im runnin out of ideas now im down to maybe the harness or a v-8 swap, HELP ME PLEASE!!!!

 

[86ford]

plug wires could have the insulation broken down to the point they arc like a coil pack will. get it started if you can in a dark area and spray down the motor with a mist/spray bottle. if you see a light show you prolly have bad wires. do you seem to have less power? if you battery is REALY weak and your alt. is on its way out you could need the motor to run a while to build up enough power to run properly(both can be tested at the local autoparts stores 90% of the time without removing them).

86

 

[brickhousen]

the plug wires are also new and it didnt help either, batt. cables were petty nasty so i replaced them, i dont understand because if and when it does start it runs great no problems at all it just dont want to fire up, and thats also funny because it being intermitant spark while cranking one would think that when it did start it would spit sputter and choke but it dont skip a beat! any more suggestions would be great just keep them coming because the tranny went out on my car and i need my tuck to get to work!

 

[Destroyer000]

maybe a back crank sensor?

 

[brickhousen]

tried that too still nothin!

 

[cocoasranger]

Does the starter spin the engine swiftly or only slowly? If slowly, the battery may be marginal and once started the engine may be running on the alternator output. When starting the alternator is not putting out much which would explain your symptoms. Simply switching in a known good battery for a test would confirm if this was the problem.

 

[brickhousen]

the starter spins alot faster now that i replaced the battery cables but i do have another battery i could throw in and try its worth a shot ill let you know how it goes!

 

[snake]

Could be a bad ignition switch or relay if it is intermittent

 

[brickhousen]

tried a different battery didnt do anything, put a new ignition switch in it that didnt help either, now the relays on the other hand i havent messed with yet are they the ones under the fuse box in the engine bay?

 

[brickhousen]

anyone know if the wires coming from the crank position sensor go straight to the coil pack?

 

[brickhousen]

tried the relays tried grounds tried replacing every part of the ignition everything including the engine wire harness still nothin the injectors and spark are intermitant if at all and now it flat out just will not start as for me im going bald and about to burn the f#@$!%* pice of shit!

QUESTIONS? COMMENTS? ANSWERES? PLEASE!!!!

 

[snake]

I hope this doesn't sound offensive, but are you sure it is not getting spark? Have you pulled a plug, put it back into the wire, cranked it around and seen if it is or isn't getting spark? Just want to make sure since it has all been replaced and still doesn't work.

I was thinking it might have an intermittent fuel problem which seems to be more commonplace with these trucks. Wish I had better advice but I'm running out of ideas too!

Also, if you can find a donor PCM and try it out- I wouldn't buy one just to try tho.

 

[almostclueless]

fuel delivery

 

[brickhousen]

no not offensive it takes more than that to get me butt hurt lol, but yes i have had a spark test light on it and just today had a noid light on one of the injectors and they both are intermitant if at all, as in crank in crank and crank an oh there was a spark and crank and crank and crank and oh theres an injector firing and well you get the idea! but it just will not start and i dont know what would cause the ignition and injection to act like that!


thoughts suggestions???? n thanks to the people who have threw some ideas out there i realy appreciate it!

 

[snake]

PCM? But as stated before, don't buy one, throwing money on parts get expensive! Find a friend and swap them.