Real time HEI problem

[Anvil]

FYI, In the past 6 hours, I've read every thread I could find here and elsewhere...

I have a 74 FJ40 with a GM HEI with the Toyota gear. I've been working on the rig for the last 1 1/2 years. Today was to be her first day on payment . i started her up, pulled her out of the shop and let her idle. Then she died!

There was no power going to the distributor. Not sure why... Fuses looked good but replaced them anyway. I ran a wire from the battery to the dizzy. Still no spark, though I did have 12.58 volts at the dizzy. Also, the rotor turns when trying to start the engine.

This same thing happen to me in January . I then replaced the coil, rotor,and module to no avail. Replaced the cap and everything was fine.

Since January, I may have driven 40 miles. I typically start her up and move her out of my shop each morning. The slightest bump of the starter, cranks her right up!

Since I had a new coil and module on hand, I replaced them today. Still no spark.

What am I doing wrong? Before the GM HEI, I installed a Man a Fre lighting unit... The counter weights flew off and mangled the dizzy. Proir to that, I had the old dizzy and would have to change points very two hundred miles.

If anyone has advise, PLEASE chime in. I'm at my wits end and could use some help!

Thank You!

 

[fhawk5]

Is that 12 volts there always or is it intermittent ? Keep a meter on the 12 volt line and observe through testing. That HEI only requires 12 volts to operate. If there is 12 volts there ALWAYS then it is a distributor issue.

 

[DougAustinTx]

Make sure the high voltage didn't burn a hole through the rotor underneath the rotating center spring. When that happens, all the high voltage goes to the distributor post that supports the rotor. Usually happens when your rotor is cheap, or when the gap between the rotor and the distributor cap is too large, so the HV looks for a shorter route to take. It only takes one time for this to happen and it will ground the HV until you replace the rotor.

 

[reddingcruiser]

I have a 74 FJ40 with a GM HEI with the Toyota gear. I've been working on the rig for the last 1 1/2 years. Today was to be her first day on payment .

I know it's a typo, but as a fellow FJ40 owner the irony is irresistible. Spending money on your rig is just part of being a 'cruiser owner.

 

[Anvil]

Make sure the high voltage didn't burn a hole through the rotor underneath the rotating center spring. When that happens, all the high voltage goes to the distributor post that supports the rotor. Usually happens when your rotor is cheap, or when the gap between the rotor and the distributor cap is too large, so the HV looks for a shorter route to take. It only takes one time for this to happen and it will ground the HV until you replace the rotor.

Thanks Doug! I'll pick up another rotor this morning and try it. I didn't realize they would burn up that quickly. Perhaps I should buy two...

Any ideas where to begin researching why the black/yellow wire has no switch on power?
Thanks again for your help!

I know it's a typo, but as a fellow FJ40 owner the irony is irresistible. Spending money on your rig is just part of being a 'cruiser owner.

Thanks for bringing attention to my typo! That must have been my sub conscious typing. I quit keeping records after I passed the $10,000 mark. I'm confident the $20,000 mark has been surpassed... Oh well, I didn't really want a boat anyhow.

 

[Anvil]

Okay, new rotor and cap ... still nothing . Any other suggestions?

Any help would be VERY appreciated! Thanks

 

[bsevans]

What gauge wire are you using for power to the HEI?

 

[Anvil]

Besevans, the wire is 14 gauge. Any thoughts?

Just had the module tested... it's good. Coil is good, grounds are good, new ca, new rotor. Only thing left to replace is the capacitor, but I thought that was only needed if you used the harness. Am I wrong?

Thanks!

 

[DougAustinTx]

This is a GM style HEI, right? When you say "coil is good" you are talking about the coil pack in the top of the dizzy I assume. No other coil should be involved. If you have 12v going to the coil plug on the dizzy (not the terminal labeled Tach), and the dizzy is grounded, it WILL produce a spark if the module is still good. While 16 ga would be better, I have run GM dizzys on 18 gauge wire and they worked ok, 14ga is really good.

 

[Gumby]

Take the cap off and have someone crank it and make sure the distributor is turning. The roll pin can shear and cause the gear to not turn the dist shaft.

 

[Rocky_LC]

You could also (temporarily) directly feed the single 12VDC wire from the battery. If it runs, you know the problem is in the feed to the distributor. On mine it was just a spade terminal that slid into the distributor housing...

The problem noted on other HEI systems is the cam gear would pull the distributor "guts" down - I thought this could short out "stuff" inside the distributor. How much "up and down" play do you have on the rotor assembly?

http://www.chuck-huber.hostei.com/hei_install.html

 

[DougAustinTx]

If I remember the wiring diagram correctly, the black/yellow wire comes right off the back of the starter switch and is hot when the switch is in the ON position. If you have the main hot wire from the battery reaching the ignition switch and it's still hot, and your black/yellow wire isn't hot when the switch is on, I would be taking a close look at the switch.

 

[bsevans]

Besevans, the wire is 14 gauge. Any thoughts?

Just had the module tested... it's good. Coil is good, grounds are good, new ca, new rotor. Only thing left to replace is the capacitor, but I thought that was only needed if you used the harness. Am I wrong?

Thanks!

Read Topic 3 on this webpage. 12 gauge is what they call for and what I ran.

HEI Distributor

 

[Anvil]

This is a GM style HEI, right? When you say "coil is good" you are talking about the coil pack in the top of the dizzy I assume. No other coil should be involved. If you have 12v going to the coil plug on the dizzy (not the terminal labeled Tach), and the dizzy is grounded, it WILL produce a spark if the module is still good. While 16 ga would be better, I have run GM dizzys on 18 gauge wire and they worked ok, 14ga is really good.

Thanks for the replies guys. I REALLY appreciate your input!
Doug, I removed the cover and checked the voltage at the red wire connection on the coil pack. It measured 12.58 volts. I'm currently running a wire directly off the start battery.

Take the cap off and have someone crank it and make sure the distributor is turning. The roll pin can shear and cause the gear to not turn the dist shaft.

Thanks Gumby, yes the rotor does turn (thankfully!)

You could also (temporarily) directly feed the single 12VDC wire from the battery. If it runs, you know the problem is in the feed to the distributor. On mine it was just a spade terminal that slid into the distributor housing...

The problem noted on other HEI systems is the cam gear would pull the distributor "guts" down - I thought this could short out "stuff" inside the distributor. How much "up and down" play do you have on the rotor assembly?

http://www.chuck-huber.hostei.com/hei_install.html

Great question... I'm not sure how much play I have. I'll have to check it in the morning. How much should I have?
I read the link. Good stuff!

If I remember the wiring diagram correctly, the black/yellow wire comes right off the back of the starter switch and is hot when the switch is in the ON position. If you have the main hot wire from the battery reaching the ignition switch and it's still hot, and your black/yellow wire isn't hot when the switch is on, I would be taking a close look at the switch.

Thanks for the advice! I'll do that once I get some fire.

Read Topic 3 on this webpage. 12 gauge is what they call for and what I ran.

HEI Distributor

Thanks Bsevans! I just read the link. I have yet to test the pick up coil . I'll give it a go in the morning.

I am truly stumped... I keep thinking I'm overlooking some small detail... Again, the capacitor is the only thing I have not replaced. Does anyone know if the capacitor is necessary if the harness is ot utilized?

THANKS again everyone!

 

[60fj25]

From what I remember a capacitor (condenser) is only used with points distributors and not needed with HEI. It was there to make the points last longer and eliminate AM radio interference. The HEI uses optical sensors and not points. I'm pretty sure I eliminated the condenser when I did my v8 HEI many years ago. (I'm now computerized 7pin HEI). Try bypassing the condenser.
Advance adapters had a note on this in their chevy conversion brochure. I tried to find mine but couldn't. You may want to give them a call to ask.

 

[Anvil]

60fj25, Thanks for the advise. I'll give them a call tomorrow. I'm completely out of ideas...

I followed the directions on the DUI troubleshooting link that Bseveans sent me. Everything checks out fine... Called a couple of mechanic friends to no avail.

Still looking for advise! Thanks!