87' R10 TBI 350 shuts off when driving. HeLP

[JamesSam]

I have seen zero codes thrown. Oil pressure never drops below 30 psi. I did replace the oil pressure sending unit about a year ago after the needle got stuck on 25 no matter what was happening. With new oil pressure sending unit guage is active.

 

[Hunter_Michael]

Does anything else electrical act strangely? Does your radio cut out? Voltage gauge needle not steady? Lights flicker? Does it only happen when hot? After how many minutes after startup does it begin to act up?

The brake light on the dash does come on when I press the brakes hard then go off. I recently replaced the drum brakes on the rear and the front discs etc. I need to re bleed the brakes, I believe is what is causing this?? But its been braking fine and no leaks.
It all happens well after its warmed up. Ive drivin it for 45 minutes and nothing. But it seems to happen more on longer trips then short. But nothing else unusual happens. I just replaced the ignition switch on the steering column yesterday along with replaceing the ignition module next to the TBI. But both the replacements looked fine. Added another ground wire from the frame to the body on the passenger side. Cleaned up the other grounds so as to make sure for a good ground.
Also added some protection on the base of the air cleaner & coil wires to ensure it wouldnt ground out to the air cleaner base, which this could actually be an issue on how close it is to the lid. But will have to drive it and see if or when it will cut out again.. Next step will be the actual ECM. May have to pull the glove box and inspect it this weekend and see the condition.

Really Appreciate all the help!

 

[Hunter_Michael]

Following this thread as my 87 has acted like it might cut out when leaving from a stop before. After this happened the first time I decided to put in all new plugs and wires. This seemed to give it new life. Recently it happened again while out driving. I also had the drivers side tank die and kill power to the truck about a year ago. Now only running on passenger side. Lots of strange nuances, but bottom line: I know the truck could benefit from new tank, lines, and sending units. I know I should also probably exchange ignition coil and see about cleaning the throttle body injectors etc. Watching for info now....

I just replaced the passenger side tank because it leaked. About $300 to get that fixed, thats the tank, sending unit with pump etc. I replaced the transfer switch at the same time. but not a hard job. I have my son run that new tank just to illiminate the drivers side tank as the issue, which it dies running on the new tank so the drivers side is fine. Ignition coil is another easy replacement and I rebuilt my TBI ($30) and it was an easy job as well. that made the truck run alot better doing that.

 

[squaredeal91]

Pickup coil?

 

[Hunter_Michael]

Pickup coil?

Brand New.. One of the first things I replaced.

 

[JamesSam]

I just replaced the passenger side tank because it leaked. About $300 to get that fixed, thats the tank, sending unit with pump etc. I replaced the transfer switch at the same time. but not a hard job. I have my son run that new tank just to illiminate the drivers side tank as the issue, which it dies running on the new tank so the drivers side is fine. Ignition coil is another easy replacement and I rebuilt my TBI ($30) and it was an easy job as well. that made the truck run alot better doing that.

I have replaced the switch (in the cab) reading that that could be why one tank won't work when switching (amongst other things). The switch itself works. The selector valve could be the problem but the way all power is lost when going from passenger to drivers side makes me think it is likely fuel pump, which is internal on 87 tanks. Also as I have mentioned In a few other posts I am fairly certain fuel bleed from one tank to another somehow when I had initially tried figuring out why the drivers tank was dunzo.

 

[squaredeal91]

Brand New.. One of the first things I replaced.

Dang...

 

[dd1990]

I had a similar issue, it turned out to be the ignition switch

 

[JamesSam]

I had a similar issue, it turned out to be the ignition switch

Not getting gas and almost stalling caused by ignition switch?

 

[gmbellew]

Following this thread as my 87 has acted like it might cut out when leaving from a stop before. After this happened the first time I decided to put in all new plugs and wires. This seemed to give it new life. Recently it happened again while out driving. I also had the drivers side tank die and kill power to the truck about a year ago. Now only running on passenger side. Lots of strange nuances, but bottom line: I know the truck could benefit from new tank, lines, and sending units. I know I should also probably exchange ignition coil and see about cleaning the throttle body injectors etc. Watching for info now....

fuel pump wiring is on ECMB fuse. probably have a short to ground in the wiring for that side?

 

[Hunter_Michael]

I drove it today for about an hour total, drove like a champ going to Lowes (30 minute drive). On the trip back it cut off twice, this time it felt like the injectors stopped pumping fuel?? 3/4 tank of gas, once at a stand still awaiting on a light and the other while driving, put it in neutral, restarted while driving and took a bit but started up like 10 seconds. then it ran fine again.

I removed the ecm and opened it up, looked fine. Put it back in. I wish I had an extra ecm laying around to see if that could be an issue... Hate to buy another part that doesnt correct the issue.

Was just able to attach the led light to the coil when I got home so if it does it again I will check if the light goes out. I just did an oil change and filter as well. not sure when it was done previously, we have put 2000 miles on it since getting it. And to boot the AC Coils are hissing... Looks like I will have to replace that as well and get it recharged....

 

[Snoots]

I'll say it again...pick-up/trigger coil inside the dizzy.

 

[Hunter_Michael]

I'll say it again...pick-up/trigger coil inside the dizzy.

Got it ordered, Will give it a try! Thanks

 

[squaredeal91]

I'll say it again...pick-up/trigger coil inside the dizzy.

New parts fail all the time

 

[JamesSam]

Drove mine today for the first time in about 5 days. It drove great, no stalls or feeling like it would cut out. Just a 5 minute drive over to my wife's parents to wish Happy Mothers Day. Top speed was ~45.