1987 s10 suddenly dying

My 87 s10 truck will just suddenly die and not want to start again. At first I thought it was a cracked cap, so I did a complete tune up, plugs wire cap etc... But today it has died twice. Then it was parked and it wouldn’t start so I popped the hood and had a friend watch the TBI to see if it was spraying fuel, and it wasn’t. So I took off the gas line to see if it was getting gas, and it was, it sprayed out of the line while turning over. But didn’t come out of the injectors, so I messed around with the wires and so on. Still it didn't start, so finally I took out the ignition fuse, wasn’t blown, turned the key and it started then died. I put the fuse back in and wiggled it around and it started and ran. So I leave and on the way home it dies again, wont start. I take the fuse out and so on, still nothing. So I push hard into the ignition switch and giggle it around, sure enough it fired up. THEN it dies again, and the key trick doesn’t work. SO I do take the fuse out and lick the prongs, don’t know why, wiggle it and wiggle key and it finally starts. What in the hell is going on here? I'm thinking bad ground/short somewhere or possibly something on the TBI...... Any ideas????

Check The Ground Wires Could Be Lose Connection. If None Then Try To Find Where Your Short Is Coming From. Wish I Could Help More But This Is Puzzleing Me Too. LOL

My 87 s10 truck will just suddenly die and not want to start again. At first I thought it was a cracked cap, so I did a complete tune up, plugs wire cap etc... But today it has died twice. Then it was parked and it wouldn’t start so I popped the hood and had a friend watch the TBI to see if it was spraying fuel, and it wasn’t. So I took off the gas line to see if it was getting gas, and it was, it sprayed out of the line while turning over. But didn’t come out of the injectors, so I messed around with the wires and so on. Still it didn't start, so finally I took out the ignition fuse, wasn’t blown, turned the key and it started then died. I put the fuse back in and wiggled it around and it started and ran. So I leave and on the way home it dies again, wont start. I take the fuse out and so on, still nothing. So I push hard into the ignition switch and giggle it around, sure enough it fired up. THEN it dies again, and the key trick doesn’t work. SO I do take the fuse out and lick the prongs, don’t know why, wiggle it and wiggle key and it finally starts. What in the hell is going on here? I'm thinking bad ground/short somewhere or possibly something on the TBI...... Any ideas????

What engine?
When it will not start does it have spark to all spark plugs?
If so check fuel pressure and then check for injector pulse.
Let us know what is failing. Spark or fuel or injector pulse

Its a 2.8 and when it wont start no fuel is going through the TBI, fuel is pumping through the fue line to the TBI though.

Have you got spark?
How much fuel pressure?

I've got spark and I dont know the fuel pressure. I think its a sensor or something on the TBI, or a ground somewhere. The passenger side keeps getting wet since the radio antenna is ripped, so the hole lets water in and it soaks the passenger side floor pan. Maybe theres a ground on that side or something... I messed with it a bit this weekend, but didnt find anything. I got it to start, but not consistently.... Any help?

I've got spark and I dont know the fuel pressure. I think its a sensor or something on the TBI, or a ground somewhere. The passenger side keeps getting wet since the radio antenna is ripped, so the hole lets water in and it soaks the passenger side floor pan. Maybe theres a ground on that side or something... I messed with it a bit this weekend, but didnt find anything. I got it to start, but not consistently.... Any help?


Proper testing is in order.
If you have good spark move on to fuel pressure check.

My friend has had a few Blazers (7).. dont know the years, I'm thinking 85-86' ish. He is a recycler. If this will help but he has repeatedly had to replace a module back in under the distributor cap for this same symptom.. He keeps several spares modules around just in case.

Good Luck

Could be ignition module/control unit cutting out I suppose. It's about 28 bucks at Advance auto. Or maybe the pickup under the rotor, if has one. Pickup is about 13 bucks at same place.

Not sure, I know when it starts its getting spark, duh I know. But when it wont start the TBI isnt delivering fuel, so I'm not sure if thats b.c spark isnt being delieverd or theres some short or sensor going bad, but I do know fuel is being delievered to the TBI when cranking the motor....

My older mustang had the same sort of condition, with random no starts, then ran fine. It was because of the ignition module. I would think yours was this case also because the fuel get's to the TBI, but doesn't spray and no spark(certainly could be ignition module doing this) when in a "no start" condition. Say's to me it's sensor related. But again, it's a cheap part so why not try it.