1984 K5 No Spark

[Cal Blazer]

Hello Everyone!

This is a long thread explaining what I have done and I think I am running out of ideas of what could be the problem.

I have a 1984 K5 Blazer with a 350 that has been in the family since new. The Blazer had been sitting for awhile so I have been working on it the past year.

I took the original distributor out that is controlled by the ECM and replaced it with a new distributor since I had a miss and changed everything from cap. rotor, wires and plugs. I figured the distributor probably had some side to side shaft play , but when I pulled out the distributor, it seemed fine. Since I had a new distributor, I installed it and it still seemed like it had amiss and ran worse.

Thinking it was a distributor problem, I bought a reman distributor and installed it and had no spark. So I figured I would install the original distributor last night with the original coil and cap and rotor. The blazer fired up and was running good. I turned off the blazer to disconnect the ECM connection so I could time it and the blazer would not start up and had no spark. I changed the cap , rotor, coil and still no spark. I do have power to the distributor and verified that the rotor is rotating when the engine is turned over. I was thinking for a minute that the timing chain gears may have been shot. I have had several cam gears go bad on other 350's before. When I changed the plug recently I did a compression check and all cylinders were at 148 or 150.

I was also thinking a module or a pick up, what are the chances my stock module went bad and having a bad reman distributor also? I am thinking about installing the new distributor that I bought to see if it produces a spark.

Any ideas would be greatly appreciated.
Sorry for the long thread! Thank you for your time.

 

[dyeager535]

Is the truck CCC or ESC? Is the new distributor a replacement for what is already there? Just making sure of your intent...I can't tell if you are swapping a like distributor, or as is common for some folks, swap to an earlier/non-ecm controlled distributor.

 

[Wes Harden]

Does the truck have a tach? If so disconnect it and try again

 

[Cal Blazer]

Is the truck CCC or ESC? Is the new distributor a replacement for what is already there? Just making sure of your intent...I can't tell if you are swapping a like distributor, or as is common for some folks, swap to an earlier/non-ecm controlled distributor.

Hi dyeager535,
I was swapping a direct replacement since I am in California and still have to smog it. I went back and took out the stock distributor and bench tested it with a hot wire to the distributor and put a spare wire on the cap with a plug in the wire other end. I rotated the distributor by hand and had no spark. I went ahead and changed the cap and rotor and coil with some spare parts I had and still not spark. I tested the reman unit with the two caps, rotor and coils on my bench system and still no spark. So I took the new distributor( Not Reman) and bench tested it with the original cap, rotor and coil that was on the original distributor and still had no spark. My last effort was to switch out the cap, rotor and coil and I got spark this time. The moral of the story is I had one stock distributor, one Reman Dist. and one new coil fail. I finally put the new distributor in the blazer and timed it and it is running great. This was a learning experience.

Thanks

 

[Cal Blazer]

Does the truck have a tach? If so disconnect it and try again

Hi Wes,

The truck does not have a tach, but I did get it running. Just two bad distributors and one coil.
Thanks

 

[Cal Blazer]

Thanks for responding to my post. I got the blazer running.
I went back and took out the stock distributor and bench tested it with a hot wire to the distributor and put a spare wire on the cap with a plug in the wire other end. I rotated the distributor by hand and had no spark. I went ahead and changed the cap and rotor and coil with some spare parts I had and still not spark. I tested the reman unit with the two caps, rotor and coils on my bench system and still no spark. So I took the new distributor( Not Reman) and bench tested it with the original cap, rotor and coil that was on the original distributor and still had no spark. My last effort was to switch out the cap, rotor and coil and I got spark this time. The moral of the story is I had one stock distributor, one Reman Dist. and one new coil fail. I finally put the new distributor in the blazer and timed it and it is running great. This was a learning experience.