No Spark, No clue...

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

tadslc

Full Access Member
Joined
Jan 20, 2020
Posts
107
Reaction score
104
Location
Birmingham, AL
First Name
Tad
Truck Year
1981
Truck Model
C10
Engine Size
305
1981 C10 305 Type H with ESC

About a week ago my truck didn't start. Figured I just flooded it so I came back a few hours later and it fired up. Problem solved or so I thought.

Since the truck is somewhat new to me and with not much maintenance history, I decided to do a tune up. I replaced the plugs, cap, rotor and HEI coil. It fired right up and I went to the auto parts store to buy an air and fuel filter.

On the way home the truck died like I had turned the switch off and lucky me (I thought) rolled right into a repair shop. I let them know what had happened so they went to work on it, replacing the fuel pump which I didn't need btw, still didn't start.

I had it towed to my house and double checked everything and also replaced the ignition control module (5-pin version). Still won't start.

Anyone have any suggestions, I'm royally confused.


Thanks,
Tad
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
3,945
Reaction score
5,697
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Check for 12v to the cap.check for spark. Give it a shot of fuel. Post back
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,135
Reaction score
4,984
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
Do basic troubleshooting and fault isolation to see where your problem is... its either air, fuel, or spark.

Hook a spark tester up to one of your plug wires and see if you get a good solid blue spark when cranking. If you do, then you need to pull the air cleaner and see if you are getting a good clean spray of fuel in the primaries when you push the throttle. If that is good, then rent a compression tester and see what your compression is in each cylinder. One of those will be bad if it isn't starting...

Your troubleshooting path will be determined by which one comes up bad.
 

tadslc

Full Access Member
Joined
Jan 20, 2020
Posts
107
Reaction score
104
Location
Birmingham, AL
First Name
Tad
Truck Year
1981
Truck Model
C10
Engine Size
305
I know it is ignition related. I am getting no spark at the plug. I am getting good voltage to the Bat terminal on the HEI distributor.

I am getting fuel. I've never had a fuel problem that just totally shut down the engine like you turned it off with the key. But I'm sure there is a first time for everything.

The truck was running perfectly before this happened so a compression check really shouldn't help.

I think it might be related to the ESC (Electronic Spark Controller). That's what I'm going to look at this evening.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
3,945
Reaction score
5,697
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Esc look up esc bypass. From memory it is cut and strip middle 2 leads from dist. Harness twist them together provide KOEO power to cap.ESC is now not partof the equation.
 
Last edited:

Camar068

Supporting Member
Supporting Member
Joined
Feb 5, 2014
Posts
4,124
Reaction score
2,963
Location
Kentucky
First Name
David
Truck Year
1986
Truck Model
K10/LM7 5.3/4L60e/np208/3.73/32"
Engine Size
10 yrs Air Force
make sure the prongs on all of your electrical connectors at the distributor are good. Mine died twice, pulled out pliers and crimped them a bit for a better connection and kept cruising.

I started to also say to get a replacement distributor from Skip White, but I don't see any SBC dizzy's on there. Might call them if it comes to you needing a new dizzy, was worth every penny @ $50 shipped to you.

https://www.skipwhiteperformance.com/catalog/category/distributors-ignition-acc_7585/
 

tadslc

Full Access Member
Joined
Jan 20, 2020
Posts
107
Reaction score
104
Location
Birmingham, AL
First Name
Tad
Truck Year
1981
Truck Model
C10
Engine Size
305
thanks guys

I tried to jumper the black and green wire from the ESC and still have a no start problem. Not ready to cut them yet...

Anyone ever replace the condenser?
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
3,945
Reaction score
5,697
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Okay unplug it and make appropriate jumper wires but I think the wires have to be disconnected from the esc box
 

DanMcG

Full Access Member
Joined
Jun 28, 2014
Posts
1,076
Reaction score
1,881
Location
Central NY
First Name
Dan
Truck Year
1978 1985
Truck Model
k10 k10
Engine Size
400 350
your new HEI coil could be bad.
 

82sbshortbed

Fuckemall!!
Joined
Mar 1, 2018
Posts
14,646
Reaction score
48,566
Location
SE Texas
First Name
Doug
Truck Year
1982, 1984
Truck Model
1500 shortbed, 1500 longbed
Engine Size
454, 305
make sure the prongs on all of your electrical connectors at the distributor are good. Mine died twice, pulled out pliers and crimped them a bit for a better connection and kept cruising.

I started to also say to get a replacement distributor from Skip White, but I don't see any SBC dizzy's on there. Might call them if it comes to you needing a new dizzy, was worth every penny @ $50 shipped to you.

https://www.skipwhiteperformance.com/catalog/category/distributors-ignition-acc_7585/


I'll second this as I have one on my BBC for $55. Worth every penny.
 

tadslc

Full Access Member
Joined
Jan 20, 2020
Posts
107
Reaction score
104
Location
Birmingham, AL
First Name
Tad
Truck Year
1981
Truck Model
C10
Engine Size
305
Okay unplug it and make appropriate jumper wires but I think the wires have to be disconnected from the esc box

Thanks Ricko, I did not unplug the ESC box itself. I'll try that next.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
3,945
Reaction score
5,697
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Not what I meant, do the bypass as directed but instead of cutting the wires which you don't want to do unplug the dizzy, make 4 jumper wires. Do the bypass on the jumper wires just like you would on original harness, then post results back.
 

Matt69olds

Full Access Member
Joined
Jan 8, 2018
Posts
2,338
Reaction score
3,571
Location
Central Indiana
First Name
Matt
Truck Year
81
Truck Model
GMC 1/2 ton
Engine Size
455 Olds
Put a test light on the tach terminal of the distributor. Turn the key on, the test light should light up. If not, either you don’t have power to the coil, or the new coil is defective.

Crank the engine, does the test light flicker? If not, the coil isn’t being triggered. You could have a defective ignition module, bad pickup coil, or mechanical failure (timing chain, worn cam/distributor gears, etc).

If you have replaced the coil and module, inspect the pickup coil wires. I bet you find one either broken, or just barely hanging on by a single strand of copper wire. No signal from the pickup coil to the module, no spark.
 

75Monza

Full Access Member
Joined
May 5, 2017
Posts
1,362
Reaction score
2,839
Location
Colville, Washington
First Name
Jeremy
Truck Year
1980, 1982, 1985
Truck Model
K30, K20, K20
Engine Size
454, 383, 350
Totally out there question, but does the distributor actually turn when motor cranked?
 

Latest posts

Forum statistics

Threads
41,857
Posts
903,628
Members
33,370
Latest member
mitchell1128
Top