major distributor issues!!!

[nac593]

I have 14,000 miles on everything new. I replaced EVERYTHING in the engine compartment. ( and most of the rest of truck. $20 k invested.) The distributor keeps goin out. At around 5000 miles it wouldnt start. Had no spark. I replaced the ignition module and coil in the HEI dist. It started right up. The same thing happened at around 8000, 10000, and 12000 miles. Every time I replace the module and coil it starts right up. Today it wont start AGAIN!!! I talked to an old time mechanic that said I have a constant voltage going to it when truck is off but I checked voltage and its zero volts. He told me to go back to points. Where is a good place to get a points distributor? and yes the ground strip is in the distrib and i used dielectric grease. Any help or ideas?

[zeeklu]

You did replace the old wire going to the distributor?That's all I can think of. Chris

[nac593]

yes i relaced the old wire

[Sinister]

Yeah, make sure you're getting 12 volts to the HEI.

[nac593]

checked it and i am

[292farmer]

whats the motor?

[nac593]

It's a 350 crate motor. 290hp. bought a chevy distributor

[mbgmike]

Originally Posted by nac593

I have 14,000 miles on everything new. I replaced EVERYTHING in the engine compartment. ( and most of the rest of truck. $20 k invested.) The distributor keeps goin out. At around 5000 miles it wouldnt start. Had no spark. I replaced the ignition module and coil in the HEI dist. It started right up. The same thing happened at around 8000, 10000, and 12000 miles. Every time I replace the module and coil it starts right up. Today it wont start AGAIN!!! I talked to an old time mechanic that said I have a constant voltage going to it when truck is off but I checked voltage and its zero volts. He told me to go back to points. Where is a good place to get a points distributor? and yes the ground strip is in the distrib and i used dielectric grease. Any help or ideas?

Did you replace it with a GM module or aftermarket. Some of the Aftermarkets are junk and will do that.
Also make sure you don't have excessive current to the Module

Excessive current will increase the temperature of
everything in the circuit. If a circuit fails in the module it can damage a coil and the coil will fail often. Likewise a partially shorted coil can destroy or damage modules.
Aftermarket ones do not always have the current limiting that they should have.

No need to go back to points. Need to check all voltage drops with a scope

[nac593]

I've replaced with napa parts and kragen parts. I've bought the cheap ones and the spendy ones. I think last time it was $45 for each part. That's $90 to fix one time. And I've fixed a few times. This is ridiculous and frustrating. I have spent hundreds of dollars. What about going to points?

[Captain Underdog]

When they say make sure you're getting 12 volts, they really mean 13.8 - 14.2 volts. Nothing runs on 12 volts unless it would be your old points coil. What kind of alternator are you running? Does it have a remote sense wire? or is it "one wire". To diagnose this you should hook a good voltmeter to the HEI power wire and drive the pickup. Watch for voltage spikes when you shut the lights/wipers/etc. off. Watch for low volts when running with all the accessories on. The HEI needs a consistent 13.8-14.2 volts.

Oh, and don't go back to points, if you are frustrated now you will learn to hate points.

[nac593]

I bought a new altenator from kragen. Its the newer style that doesnt use the voltage regulator mounted on the radiator support. I will try your advice but I need to get the truck running again! I am sick of breaking down and spending all that money to go a couple thousand miles! The wife wants me to sell it because of the problems. I replaced everything on the truck to make sure it"s reliable< but it keeps breakin down

[cdowns]

do you have good clean bright and shiny ground connections everywhere that is needed?

[vectorit]

I wouldn't go back to points, but if you are ready to scrap the HEI... Then look at Pertronix.

Seriously though, the HEI shouldn't be going out that often.
Have you taken the rig to an automotive electrical specialist? Rather than throw money away at parts, take it to a specialist and describe what is happening.

[mbgmike]

I doubt if its the alternator. You don't need to keep buying parts. Need to check for voltage drop with a scope. These problems generally lie in the coil and module. You need to know what it is

[Captain Underdog]

I'll say it again; check the voltage supply to the HEI under driving conditions. We are running lots of newer electronics on an electrical system that wasn't designed to provide the power that the electronics need. A bigger/newer alternator like you already have is a good start, however the system must be wired to provide a consistent share of that power to everything that needs it. If your voltage supply to the HEI is fluctuating the cure is pretty simple and easy to do.

[mbgmike]

Originally Posted by Captain Underdog

I'll say it again; check the voltage supply to the HEI under driving conditions. We are running lots of newer electronics on an electrical system that wasn't designed to provide the power that the electronics need. A bigger/newer alternator like you already have is a good start, however the system must be wired to provide a consistent share of that power to everything that needs it. If your voltage supply to the HEI is fluctuating the cure is pretty simple and easy to do.

I agree. You want full voltage to the HEI. need to remove any resistor wire that would be preventing that and replace with non- resistant wire

[dan42]

Originally Posted by Captain Underdog

I'll say it again; check the voltage supply to the HEI under driving conditions. We are running lots of newer electronics on an electrical system that wasn't designed to provide the power that the electronics need. A bigger/newer alternator like you already have is a good start, however the system must be wired to provide a consistent share of that power to everything that needs it. If your voltage supply to the HEI is fluctuating the cure is pretty simple and easy to do.

X2 - goofy crap happens when you are driving around - that's gotta be it. I'm having issues with my retrosound radio (that's been replaced three times) and it's probably the same type of issue - getting a surge from something.

[mcbassin]

This is a strange situation indeed. I replaced my points setup back in 87 right after I got my 70. Originally I didn't even run a new wire, never had any trouble with it other than changing plugs and wires. Probably put about 50k miles on it daily driving to work. I am still running the original alternator setup.
I wonder if you are getting a spike like stated earlier?

[mbgmike]

Originally Posted by mcbassin

This is a strange situation indeed. I replaced my points setup back in 87 right after I got my 70. Originally I didn't even run a new wire, never had any trouble with it other than changing plugs and wires. Probably put about 50k miles on it daily driving to work. I am still running the original alternator setup.
I wonder if you are getting a spike like stated earlier?

They can still run using the resistor wire but it causes a huge current loss. Its better to change out to 10guage wire

[mcbassin]

Originally Posted by mbgmike

They can still run using the resistor wire but it causes a huge current loss. Its better to change out to 10guage wire

Totally agree with changing to the 10g wire, I didn't know at the time of the upgrade, (young and ignorant) just tried it and it worked for about 12 years. I wouldn't do it again, it's too easy to change out with bigger wire.

[Captain Underdog]

My 68 went this way. The main power wire went from the batt to the horn relay and from there to the power supply for the cab. I installed a power distribution point (big power stud covered in red plastic covers off of a '03 GM something.) on the firewall and supplied it with power from the batt with a 6ga red wire. I then took the #2 small red wire off the internally regulated alternator two prong plug and ran it to the power dist point so that it would sense the voltage at this point. Then the cab, the ignition, and everything else that needs power gets it from this power point. The big red wire from the alternator runs down to the starter end of the battery cable. This was run this way to isolate the alternator from the rest of the system to minimize speaker buzz in the two-way radio. The battery stands between the system and the alternator.

With it done like this, the voltage at the power point never varies no matter the load. With your situation this would shorten up the wire supplying the ignition and stabilize the voltage supply to your ignition system.

Sounds complicated but it works and it's really simple.

[mbgmike]

Is this a factory Hei distibutor?with spark control

You can check the module to see if its working by
disconnecting the 4 wire terminal from the module to
the esc if you have one.
If you have good power from the distributor
it should spark
You can pull the distributor out give it power and ground and spin it by hand and it
will spark if the coil and module are good.

[nac593]

I have redone All gronds and extra grounded everything. I know it shouldnt go out that often and thats what is frustrating. I took it to an electrical specialist for a different problem and it was kinda a joke. They just replaced parts until fixed. I coulda done that. I will take the advice of checkin voltage when running but I need to get it running again.

[mbgmike]

Here is a good article.
http://rmcavoy.freeshell.org/HEI.html

[Captain Underdog]

That's the beauty of forums like this; we usually do better than throwing parts at it. If you can use a scope like mbgmike says, that would be best. A scope is just a voltmeter displayed on a time line so you don't miss anything. If you don't have access to a scope just use a volt meter with a friend watching it as you drive.

If your pickup is wired like mine from the factory you will have to change some supply wiring to get consistent supply volts to everything. It's easy and simple. Take heart, you are almost done with this problem for good.