I need some help..... 86 GMC problems!!!

[Kenbo-Slice]

Hey guys. I'm new to this "older" truck world. I don't know about big motors, carburetors and POWER.

So heres to problem.... This truck is a bear to me! I am slowly trying to get this thing reliable (an 86 GMC 3500 dually). The truck has a 454, TH400 and is 2wd. I have recently ran into a problem with the ignition. The truck will start and I'll drive it and when I shut it off it will not start again. I don't mean that it wont fire... It will not do ANYTHING! I'll turn the key and get nothing. No noise no nothing. The clock in my dash is still running so I know I have power. I have no idea what it could be. Any ideas gentlemen (or women)?

Also, The truck was running great all day yesterday until last night. I started it and it was idling so low it would bumble and then stall. I would start it a few more times and it did the same thing. Try it once more it would start and idle fine. Today it was doing the same thing... VERY low idle. I planned on buying a new carb since the local carb shop wanted $225 to rebuild it and i could get a new Quadrajet for about $50 more (then tear apart the one I have and re-build it myself to learn/practice) Does the idle problem sound like a carburetor problem or something else?

[old Rusty C10]

the first problem is prolly a neutral safety switch... see if you take the truck out of gear and see if it starts in neutral or any other gear... also try to push the gearshift further to the left or further into park and see if that helps.. MAKE SURE YOU KEEP THE BRAKE STAMPED ON AND YOUR PARKING BRAKE SET WHEN YOU TRY THIS
the second problem sounds like a choke

[Kenbo-Slice]

My steering column is SLOPPY

My carb has NO choke. Hahaha Very possible on both counts. Thank you!


Anyone else, wanna chime in!?

[Kenbo-Slice]

Both of the problems JUST started happening today though. Just a coincidence?

[Kenbo-Slice]

So I don't think the neutral safety switch is the culprit......

It seems that there is no power going to the ignition. When I turn the key no lights or anything come on. Maybe I have a loose ground but it's still making enough of a connection to run somehitng small like the clock in my dash? I need to get this figured out and it's killing me! haha. Anybody with some more ideas?

[datguysaL]

ha, check this out.. lol

ok, are you running headers on your truck?

the stumbling it probly caused by same problem.

get up under your truck and check to see that your heat shield over the starter is in place,

i had the same problem on my 87 chevy western hauler crewcab dually 454. it first began with a cracked manifold on the passanger side, and that heat was aiming directly at the starter, and again it happend when i replaced it with a new set of headers.

lemme know it thats the problem.

[Kenbo-Slice]

The starter may be overheating?

That very well could be! It will work fine until the truck gets warm, then if I shut it off and try to restart it, it won't work. If I wait a few minutes, it will start fine. I'll check that out tomorrow! Thanks man, I appreciate it!

[datguysaL]

aight, let us know if thats the problem...

[85Bowtie]

I would check and clean your battery connections as well. It is possible to have just enough power to signal your key buzzer and things like that and not enough to engage the starter solenoid. A bad connection could cause the second problem as well in somewhat the form of a weak ignition.

I have no idea how an overheating starter would cause your stumbling problem, that makes no sense to me. As long as the solenoid activates and engages the flywheel then disengages I don't see how that's one bit related to your stumbling.

[355bullet]

Starter solenoid

[JOEGMC]

My truck did the same thing, and one day I pulled the starter off my parts truck and slapped on it, and its been fine ever since.