88 f250 wont start... heres one for ya

[ghost183]

picked up an 88 F250 4x4.. 351 / C6 / AC... clean, unmolested truck.. roughly 100k on the clock.. all original parts... minus tune up parts ofcoarse..... heres my question.. ive been fiddling with it now for a few days .....

and cant figure it out..

when i pick it up... car was sitting for about a year, had a new battery installed when it was parked so i put cables on it.. let it charge for about 10 minutes... and she started right up!!, high idle, bout 3 minutes later.. started to drop to low idle... soon as i took the positive cable off..... died instantly and never started again... what gave?.. now it cranks and cranks and cranks.. but nothing...

checked fuel....good
checked spark... no good

where did it go??



my funds are limited due to me dumping money in my other truck... so im asking where you guys think i should start first?..

[Torqued]

Originally Posted by ghost183

picked up an 88 F250 4x4.. 351 / C6 / AC... clean, unmolested truck.. roughly 100k on the clock.. all original parts... minus tune up parts ofcoarse..... heres my question.. ive been fiddling with it now for a few days .....

and cant figure it out..

when i pick it up... car was sitting for about a year, had a new battery installed when it was parked so i put cables on it.. let it charge for about 10 minutes... and she started right up!!, high idle, bout 3 minutes later.. started to drop to low idle... soon as i took the positive cable off..... died instantly and never started again... what gave?.. now it cranks and cranks and cranks.. but nothing...

checked fuel....good
checked spark... no good

where did it go??



my funds are limited due to me dumping money in my other truck... so im asking where you guys think i should start first?..

I'll make a SWAG and guess that when you removed the jumper cable it caused some sort of a voltage spike that nuked some sensitive electronic part. If the connections to the truck battery weren't clean & tight then when you removed the jumper cable the alternator started to operate with the battery disconnected. They can spike to a high enough voltage level that sensitive parts can be damaged. The battery helps to absorb those spikes and helps regulate the alternator. Be sure all the alternator and battery connections are checked before you put new parts in.
I'd start with the ignition module. My book says you may have either a Duraspark II module(mounted separate from the engine) or a TFI module (screwed to the side of the distributor). I believe the Duraspark can be tested for free at many auto parts stores. If you have a TFI then you may want to try a junk yard or try to borrow one to test. Better to test yours in someone elses truck so you don't burn up your friends module. The last one I bought new was about $60. Before doing either I'd follow and check all the wires and make sure the connections are clean and tight.
If you have the TFI module and it is good, a damaged computer could be the problem.
If it is a bad TFI module, be sure to use the special thermal grease when you mount the new module. They won't last long without it.