engine dies

[70-Chevy]

Gentleman (and Ladies),
My dad has a 66 chevy c-10 shortbed that he just put a brand new built 383 stroker motor in. The motor was broke in great and ran great at the start of this project. He had a stock GM HEI distributor with the big volt coil and high performance module installed in the distributor. With this setup it wasnt running bad at all, but it didnt feel like a true 383 should when it came to "pep". So he found a good deal on a brand new msd distributor, #msd-8360 on summitracing.com, and installed that with a high performance stand alone coil that mounts to the firewall. The motor fires right up perfectly when it is jump started, but then after almost exactly a minute, the voltmeter drops from 13 down to complete dead. The motor wont even try to crank and the lights wont even turn on. But as soon as you touch the jumper cables to the battery from another engine, she fires right up to 13 volts.

Now, my father has been over this thing for a month. Hes checked the grounds, he has brand new ground cables in all the right spots. He has checked the proper distributor hook up numerous times. Is there anything else you guys and gals can recommend on why this motor is having this electrical problem. He's mad at the world because he wants to drive and break in this motor completley, but he cant get down the road more than 200 yards. ANY suggestions would be greatly appreciated. I will take your suggestions and talk to him back and forth on this issue. You guys have helped me on issues numerous times before with my truck and I couldnt think of a better place to try to get help for him than here. Thanks in advance!

Chris

[70-Chevy]

Also, he has rewired the complete engine bay so all wires are brand new and not grounding out anywhere. He has double checked the wiring numerous times. The coil is a blaster 2 coil that mounts to the fire wall also.

[GREASEMONKEY72]

check the alternator?

[Evans]

Replace the battery ??? Sounds like it has a dead cell or 2 and won't hold a charge.....

[70-Chevy]

he has been through 3 brand new alternators. Thats not the case. I have told him to try and replace the battery, but I dont think hes tried that yet. He has a dry cell in the truck now. And I know for a fact that when those things take a dump, they really take a dump. Maybe Ill bring my battery up for when I go see him this weekend. Do you guys think the dry cell could be alot of the issue? any experiences? Thanks guys! Keep em coming!

[GREASEMONKEY72]

could just be a dud battery, try it with yours like you said and see what happens

[Evans]

No experience with dry cells ... only regular ones.... Had a Jeep that wouldn't stay running cuz the batt. was that dead the alt. couldn't charge it ... and the 5.0 Stang I had, the batt. wouldn't hold a charge more than 12 hrs till' it was down low enough not to start the Stang

[71tahoe]

Voltage regulator?

[70-Chevy]

the alternator is a brand new 140 amp internal regulator alternator. He did remove the old external regulator and all the wiring that was with it. But that was done before the distributor swap, so we know that issue was fixed. Ill try switching the battery and see what that does. thanks guys! let me know if you can think of anything else.

[70C10Toejam]

try the battery first, or at least leave the jumper cables on for a few seconds after it starts. most alternators need some maintained voltage to get them working. at least with a new battery, with it running you can check the voltage, should go from 12.6-13 volts up to around 14-14.4 when the alt is working.

any battery of any type of construction takes a dump.

is it a dry-cell, or a sealed battery???

sealed could be:
1-maint. free lead-calcium
2-gell cell--the electrolite is actually gelled
3-AGM---absorbed glass mat is actually wet, but all the water/acid is in glass mats between the plates. no acid is supposed to get out.

[truckdude239]

charging should be around 14-15 volts

[70C10Toejam]

Originally Posted by truckdude239

charging should be around 14-15 volts

anything over 14.4 is getting too much...15 is WAY to much.

[68gmsee]

Something is breaking down after a minute of running.
Truck fires right up with a jump start after it shuts off.

Sounds like an electrical component its breaking down. Could be internal short in the battery, starter or coil. Whatever it is, it's enough of a load to pull all the power.

A battery could have an internal short that can suck the juice out of the alternator and maybe cause this problem but I've never experienced this before. Also, if the alternator is good it should keep the truck running even if the battery is bad.

Definitely a weird one. Keep us posted on what you find.

[70C10Toejam]

alts need some time with the battery to "build up the field" to get them working. you can't just start it and disconnect the jumper battery. the alt won't kick-in. it only takes a few seconds, but you would be supprised how many people disconnect the jumper battery the moment the engine starts.

[Baketown Scotty]

Did you ever find out what the problem was? I have the exact same issue with 383, MSD-8360 Dist and Blaster 2 coil. Starts and runs for a minute the dies. Will turn over but not start unless I wait 20-30 minutes. Then same thing.

[Secret Squirrel]

Could be the hot wire coming off the alt. Painless kits used the wrong gauge from what I've herd. I have the same symptoms with new battery and one wire alt. I was told to change out the wire. If nothing else, should be easy to check.

[VetteVet]

The logical thing to do would be to put the GM HEI back in and see what happens. If it runs ok again then the MSD unit is at fault.

[cooperhw]

Originally Posted by Baketown Scotty

Did you ever find out what the problem was? I have the exact same issue with 383, MSD-8360 Dist and Blaster 2 coil. Starts and runs for a minute the dies. Will turn over but not start unless I wait 20-30 minutes. Then same thing.

Doubt he will answer as this thread died about 8 years ago. Contact VetteVet. Knows his sh*t on electrical.
Was probably the battery.

[67 chevelle]

This thread is 8 years old . The original poster has not been on the board for 4 years , I doubt you will get an answer

[VetteVet]

Originally Posted by 67 chevelle

This thread is 8 years old . The original poster has not been on the board for 4 years , I doubt you will get an answer

I noticed that but I thought it was worth while to point out that going back to what was working might help.

For Scotty, it is most likely the module, Have you checked it for spark after it failed? They will overheat and fail and then when they cool the engine will start.
Sometimes they fail and will not recover.

[Jonlopes]

Every time I have tried the fancy (Non-stock) distributors I have had either no change whatsoever in performance or terrible reliability (or both). The stock HEI system is great and the gains you would get from a high performance system would be next to nil even if they did last as long.

[Baketown Scotty]

What year did HEI come stock in? When I built the 383 I switched to HEI. My 1969 Blazer came with points when I got it. I did not check for spark after dying (yet). The MSD distributor is smaller than stock HEI I believe. Hopefully a stock HEI will fit without massaging the firewall.

[Baketown Scotty]

From what I can tell the MSD is plug and play with no option to change out just the module.

[leftybass209]

Originally Posted by Jonlopes

Every time I have tried the fancy (Non-stock) distributors I have had either no change whatsoever in performance or terrible reliability (or both). The stock HEI system is great and the gains you would get from a high performance system would be next to nil even if they did last as long.

Those distributors are designed for and perform well in properly designed and set up high rpm applications where an hei distributor wouldn't be able to keep up.