Picked up a 1970 GMC C3500 dump truck that needs some TLC
- Thread starter pclausen
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pclausen
Veteran Member
Stu, I feel that part of the charm is to rebuild you own engine with a gem of a core that you discovered yourself! Hence my desire to rebuilt a small block for this truck when the time comes myself
I will thoroughly check the ignition system when I get a chance! Keeping fingers crossed that's the problem!
I will thoroughly check the ignition system when I get a chance! Keeping fingers crossed that's the problem!
woodlandfarms
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Did you check your fuel? In a way it sounds like you might have a clogged filter or intake. Old rusty truck shaken around a bit.....
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pclausen
Veteran Member
Fuel was my 1st thought, but since it doesn't even attempt to fire using engine starter, I don't think that is the issue, at least not the primary one.
So I checked if I have 12V going to the coil through the relay I added and I do. I then popped the cap off, and everything inside looks new still (only got maybe 50 miles / 5 hours on the new rotor and cap).
I measured 270 ohm between the red and center wire as indicated by the yellow arrow in the pic below. Measured open between the center wire and the other outside wire and between the 2 outside wires.
The inside of the cap also looks like new with no signs of anything amiss.
And here is the coil itself. I'm getting about 0.5 ohm between the red and yellow, and open between either of those wires and the 2 black ground wires.
Not really sure what reading I should be getting, but it seems to me that my readings are off?
I guess the next step will be to put it all back together, pull one of the plugs, and see if I have spark when cranking the engine over. Need a helper for that test.
And with the plug out, might as well check compression on that one cylinder just for grins.
I did verify that the rotor is solid with no slop and it does turn when I crank the engine.
So I checked if I have 12V going to the coil through the relay I added and I do. I then popped the cap off, and everything inside looks new still (only got maybe 50 miles / 5 hours on the new rotor and cap).
I measured 270 ohm between the red and center wire as indicated by the yellow arrow in the pic below. Measured open between the center wire and the other outside wire and between the 2 outside wires.
The inside of the cap also looks like new with no signs of anything amiss.
And here is the coil itself. I'm getting about 0.5 ohm between the red and yellow, and open between either of those wires and the 2 black ground wires.
Not really sure what reading I should be getting, but it seems to me that my readings are off?
I guess the next step will be to put it all back together, pull one of the plugs, and see if I have spark when cranking the engine over. Need a helper for that test.
And with the plug out, might as well check compression on that one cylinder just for grins.
I did verify that the rotor is solid with no slop and it does turn when I crank the engine.
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Any spark at the plugs or coil wire.
My Grandmothers olds did exactly the same as your truck and it was the distributor pickup under the cap...
What about taking the distributor from the spare engine in the garage?
I agree, starting fluid should at least get you a "Pop"
My Grandmothers olds did exactly the same as your truck and it was the distributor pickup under the cap...
What about taking the distributor from the spare engine in the garage?
I agree, starting fluid should at least get you a "Pop"
FairfaxStu
Gold Member
If you have a timing light, you should be able to place it where you can see it from the driver's seat. No helper needed.
-Stu
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pclausen
Veteran Member
Ah, good point Stu. I'll do that. Should have done that to begin with before pulling the cap...
Will probably pick up a distributor pickup and coil from Napa just in case. I never did pull the distributor or reconditioned it or anything before. Just slapped a new rotor and cap on it.
Ultra, the distributor on the 350 is the original '69 points based one with external coil. I'll like to leave that one alone if at all possible.
Will probably pick up a distributor pickup and coil from Napa just in case. I never did pull the distributor or reconditioned it or anything before. Just slapped a new rotor and cap on it.
Ultra, the distributor on the 350 is the original '69 points based one with external coil. I'll like to leave that one alone if at all possible.
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pclausen
Veteran Member
Maybe I should just get this HEI tuneup kit. It comes with everything.
FairfaxStu
Gold Member
Sounds like you have already purchased it. Personally, I like to diagnose the problem first and fix it discretely. Then I may consider an upgrade like this. However, if you buy the kit, you have the ability to replace anything and everythings in the mix. Since you have to deal with the mountain on trips to the parts stores, it may not be a bad idea to pick this kit up. Worst case, you could return it unopened.
-Stu