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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: Olc2193 on February 03, 2016, 09:38:33 pm

Title: Heart of a chevy.
Post by: Olc2193 on February 03, 2016, 09:38:33 pm
Alright guys this will be lengthy. First of I have owned 2 square body gmc's in my day and love them. Now's for the interesting part I now own a 1978 jeep cj5 but it has a 1986 305 out of a c10 in it and it will not start or even back fire. Now before you tell me the basics I have replaced cap, rotor,icm,coil,plugs, I've advances the timing I've checked for spark (has spark) but still no ignition. I am going to replace the rest of the distributor next but if anybody can help me please do.
Title: Re: Heart of a chevy.
Post by: FlatBlack77 on February 03, 2016, 10:23:33 pm
check to make sure the distibutor rotor isnt off. as in the rotor wasnt aligned when the distributor was dropped in.
Title: Re: Heart of a chevy.
Post by: hatzie on February 04, 2016, 02:20:47 am
If you have spark but no fire...
Did you remove and re-install the distributor?  If YES have you checked the static timing?
Does she fire when you drip some fuel down the  carb throat?
Title: Re: Heart of a chevy.
Post by: Olc2193 on February 04, 2016, 04:27:47 am
I spray gas or carb cleaner in the carb and still no fire. When I advance the timing by twisting the distributor all the way towards the drivers side I get the half burnt fuel smell but no backfires or even trying to start. The rotor does spin.
Title: Re: Heart of a chevy.
Post by: Olc2193 on February 04, 2016, 04:36:47 am
I haven't taken the distributor out. That's my next step. I'm mechanically capable but not extremely experienced, especially with timing issues.
Title: Heart of a chevy.
Post by: roundhouse on February 04, 2016, 08:55:33 am
Could be a lot of things

If you have spark.  You need to make sure it's arriving at the proper time

Turn the engine over by hand and match the timing mark on the crank pulley to 0
Get an old distributor cap
 and use a Dremel to remove everything in the center Of the cap  just leaving the electrodes for the spark plug wires around the perimeter.    Making a window so you can see exactly where the rotor is pointing

That way you can be sure that the rotor is pointing to number one electrode
Trace all the wires and make sure they go to the proper cylinder in the proper order

Put the original cap back on and try to crank it

I assume you're able to look down in the carb and see gas spray in when you open the throttle ?





The other issue you may run into is that the crank pulley may have shifted or may not be the right one or the timing pointer may not be the right one

If making a window so you can see the rotor is lined up properly doesn't help.   There's a couple other things to check

The dizzy could be installed 180 degrees off
The cranks spins twice while the cam that drives the dizzy , only spins once
Because when the timing marks line up on the crank pulley you don't know if the crank is on the compression stroke or the exhaust stroke

Easiest way I know to find out for sure is to pull the drivers side valve cover and rotate the Engine until both valves on the number one cylinder are closed and then timing marks should be lined up

But usually if the dizzy is installed 180 off.  The engine will usually cough and sputter and blow flames back thru the carb



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Title: Re: Heart of a chevy.
Post by: gunrac on February 04, 2016, 11:22:16 am
just curios, did you get this outfit in a non running condition?
Title: Re: Heart of a chevy.
Post by: Olc2193 on February 04, 2016, 02:35:02 pm
Yea I bought it not running but I payed 750 and it has no rust so even if I have to swap this engine it was well worth it.
Title: Re: Heart of a chevy.
Post by: FlatBlack77 on February 04, 2016, 07:14:48 pm

Get an old distributor cap
 and use a Dremel to remove everything in the center Of the cap  just leaving the electrodes for the spark plug wires around the perimeter.    Making a window so you can see exactly where the rotor is pointing


this is a neato burrito idea to have in your bag of tricks! thanks for sharing dude
Title: Re: Heart of a chevy.
Post by: hatzie on February 04, 2016, 10:46:52 pm
Just spitballing here...
Did you run a compression check?
No use troubleshooting fuel or ignition issues if the engine is fubar.

My Droid from orbit

Title: Re: Heart of a chevy.
Post by: gunrac on February 04, 2016, 11:03:32 pm
Yea I bought it not running but I payed 750 and it has no rust so even if I have to swap this engine it was well worth it.

Very good buy.....Toy r toys.......but I sold a very clean 98' 4 cyl. 2 yr. ago, 70,000 mi. .......$.4,500......just an idea on what ya got.
Title: Re: Heart of a chevy.
Post by: gunrac on February 04, 2016, 11:09:01 pm

Get an old distributor cap
 and use a Dremel to remove everything in the center Of the cap  just leaving the electrodes for the spark plug wires around the perimeter.    Making a window so you can see exactly where the rotor is pointing


this is a neato burrito idea to have in your bag of tricks! thanks for sharing dude


Yes, he shares a lot of wisdom.