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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: cwilson jr on June 25, 2014, 02:35:12 pm

Title: ignition
Post by: cwilson jr on June 25, 2014, 02:35:12 pm
My 85 k10 with esc deleted was progressively cutting out and not firing back up until the truck had completely cooled, where it would start right up like nothing happened.  I replaced the icm a couple of months ago and it cured about 90% of the issue, but has since did the same thing twice.

I'm pretty sure this is ignition related.  My complete fuel system is new, other than the carb, which i believe is fine and I don't think this is vapor lock.

What should I look into next?  I'm thinking the pickup or the coil that sets on top?
Title: Re: ignition
Post by: rich weyand on June 25, 2014, 02:54:40 pm
Coils usually last a long time, but your truck is almost 30 years old.  Did you ever replace the coil?  When they start to go, they can become temperature sensitive.
Title: Re: ignition
Post by: timthescarrd on June 25, 2014, 03:11:21 pm
How was the ESC deleted? did they jumper the connectors or actually replace the distributor with a proper Vacuum-advance one?
Title: Re: ignition
Post by: bd on June 25, 2014, 03:30:18 pm
Nowadays, the aftermarket Super 65kv HEI Distributor (http://www.ebay.com/itm/SBC-BBC-CHEVY-350-383-SUPER-65K-HEI-DISTRIBUTOR-6500-R-/351066394428?pt=Motors_Car_Truck_Parts_Accessories&hash=item51bd300f3c&vxp=mtr) is so inexpensive it's no longer practical or cost effective to replace more than cap and rotor.  If you think you have a distributor problem, rather than patch your old distributor together with replacement pick-up and ignition coils, install a complete new assembly - they're cheap!
Title: Re: ignition
Post by: VileZambonie on June 25, 2014, 07:50:20 pm
Agreed, and most likely a bad pickup coil. Just replace the whole unit.
Title: Re: ignition
Post by: rich weyand on June 25, 2014, 08:18:15 pm
Nice one, bd!  How the heck can they sell that for $40???
Title: Re: ignition
Post by: Irish_Alley on June 25, 2014, 11:04:05 pm
or it could even be the icm. and they are the type of part that may test well but once theyre hot they will fail. best bet like stated above is a whole unit
even clear ones for $45
(http://www.kmjent.com/ebay/KMJ/KMJ%20PE350C.jpg)
http://www.ebay.com/itm/Chevy-SBC-350-BBC-454-65K-Coil-HEI-Electronic-Distributor-Red-Cap-/181434062938?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a3e50185a&vxp=mtr
or yet a little cheaper another red one for $43.69
http://www.ebay.com/itm/Chevy-SBC-350-BBC-454-65K-Coil-HEI-Electronic-Distributor-Red-Cap-/181434062938?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a3e50185a&vxp=mtr
Title: Re: ignition
Post by: cwilson jr on June 26, 2014, 10:02:23 am
Someone before me already put a distributer with vac advance in, but who knows how long ago.  I've  had the truck myself going on something like 10 years now.

It sounds like the new setup is the way to go.  Is there anything I need to know about dropping the new one in?  Am I going to have to mess with the timing by doing this?
Title: Re: ignition
Post by: bd on June 26, 2014, 12:54:39 pm
You will have to reset the timing when you're done.  The service distributor will eliminate the ESC connection to the distributor.

The following steps are a guideline on how to swap the distributor out.

Using a crayon, find and mark the #1 spark plug wire and terminal on the old cap.  Then with a pen and tape, mark the remaining plug wires in a clockwise direction, according to the firing order (1-8-4-3-6-5-7-2).  Now, find the matching #1 terminal on the new distributor cap and mark it.  Make redundant matching marks on the both distributor housings centered below the #1 spark plug terminals.

Remove the cap from the old distributor.  Crank the engine until the rotor points toward the #1 terminal using the mark you made on the distributor housing.  Use the crayon to make marks on the intake manifold where the rotor is pointing, and where the vacuum nipple is pointing off the vacuum advance.  Make a mental note where the rotor is pointing in relation to the mark you made on the distributor housing - the rotor probably will not align to the #1 mark on the distributor exactly.

Loosen and remove the distributor hold-down bolt and clamp.  Slowly pull the distributor straight up while watching the rotor.  The rotor will rotate clockwise as you lift the distributor.  Note where the rotor is pointing as it stops rotating - when you install the new distributor the rotor will need to be aligned in the same direction as you begin to drop the distributor into place.  As the distributor settles into position, the rotor will rotate counter-clockwise and point to the mark you made on the manifold in the same direction as the original before removal. 

If the distributor does not drop all the way down you will have to rotate the oil pump drive slightly to align the drive with the key at bottom of the distributor shaft:  Slowly remove the distributor again and use a long flat blade screwdriver to engage the oil pump drive and nudge the drive 1 - 2° in either direction.  Then re-install the distributor.  Repeat as necessary until the distributor drops fully into position.

Reinstall the distributor hold-down and bolt, but do not tighten.  Rotate the new distributor until the vacuum advance points to the mark you made on the intake manifold; the rotor should point to its mark on the intake and have similar offset to the #1 mark on the distributor housing as it had before removal.  Reconnect all the wiring, start the engine, set the timing, and tighten the hold-down.
Title: Re: ignition
Post by: pholliday1 on June 26, 2014, 02:27:02 pm
What would the site do without BD? You may have to change your name to the "Professor" LOL :)))
Title: Re: ignition
Post by: bd on June 26, 2014, 04:56:42 pm
At the very least, my posts are cures for insomnia....   ::)
Title: Re: ignition
Post by: posifour11 on February 25, 2016, 12:20:12 pm
Sorry to Lazarus this one as a new guy. I just ordered this distributor and got it today. It looks amazing for the price. I'll be installing it tomorrow, probably.

You guys are a wealth of information!

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