Has spark and fuel, no start

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.

bonanza1979

Junior Member
Joined
Oct 8, 2021
Posts
4
Reaction score
2
Location
Michigan
First Name
Travis
Truck Year
1979
Truck Model
K10
Engine Size
383
My 1979 k10 (was told has a 383) was running fine one day when I parked it and then the next day I went to start it and it fired for a second, then just cranked and would not fire at all. It is getting fuel and spark, I changed cap and rotor and ignition control module and tested several plugs and it appears to be getting good spark. I put timing mark at TDC and the rotor was pointing at the #1 position so I assume timing is still on. I haven't tried compression test as my tester is junk. Anyone have any suggestions on what this could be?
 

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
My 1979 k10 (was told has a 383) was running fine one day when I parked it and then the next day I went to start it and it fired for a second, then just cranked and would not fire at all. It is getting fuel and spark, I changed cap and rotor and ignition control module and tested several plugs and it appears to be getting good spark. I put timing mark at TDC and the rotor was pointing at the #1 position so I assume timing is still on. I haven't tried compression test as my tester is junk. Anyone have any suggestions on what this could be?
Well, since you only need three things to make an internal combustion engine run... and you just said you tested and have 2 out of three... I'm going to say either go get a good compression tester and check it, or pull your valve covers and see if something is mechanically screwed that would keep you from having good compression.
 

bonanza1979

Junior Member
Joined
Oct 8, 2021
Posts
4
Reaction score
2
Location
Michigan
First Name
Travis
Truck Year
1979
Truck Model
K10
Engine Size
383
Pulled the valve covers they all seem to be working fine. Just weird that it fired for a second and then would not even sputter or anything.. not sure what else to try
 

deerejohn

Junior Member
Joined
Dec 16, 2020
Posts
16
Reaction score
12
Location
idaho
First Name
tony
Truck Year
1987
Truck Model
k1500
Engine Size
350
i shot in the dark. water in fuel? pour fresh gas in carb to see if it fires?
 

deerejohn

Junior Member
Joined
Dec 16, 2020
Posts
16
Reaction score
12
Location
idaho
First Name
tony
Truck Year
1987
Truck Model
k1500
Engine Size
350
meant to say a shot in the dark. ha ha
 

bonanza1979

Junior Member
Joined
Oct 8, 2021
Posts
4
Reaction score
2
Location
Michigan
First Name
Travis
Truck Year
1979
Truck Model
K10
Engine Size
383
Ive tried starting fluid down the carb and won't even sputter or backfire or anything. Is it possible the timing chain jumped a tooth or two, just enough where it won't fire at all? I figured even if timing jumped a little it would still backfire or do something. Only other thing I can think is maybe the spark looks good but isn't enough to ignite the fuel. Should I try a new coil?
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,121
Reaction score
6,038
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
is your return spring on your throttle, your choke closed(at least immediately, after some starter and attempts then it should logically not be as closed hopefully) and your throttle at the idle stop(Aka the throttle cable is good, throttle at idle not WOT) and how is your distributor turned, bump it and maybe it was loose? maybe your mechanical advance is kicked out because rust or springs weak in distributor
also is your spark good and strong, take a plug and test spark through a plug like yours and check for fouling too, maybe some fouled plugs and spark is not strong and thus isnt producing the needed oomf in addition to other small things that could add up to your situatio

plug wires good? any carbon tracking on the plugs? any etching or loss of material on the cap towers? Any old dirt and stuff? I would clean plug tips, cap towers with denatured or rubbing alcohol and some shop towel to ensure no conductive buildup is able to provide a path to ground beside the intended tower/wire nubs, ensure your wire is making proper contact and is not high resistance with ohm meter and clean the plug wire ends with alcohol and swabs. if wires are due for change you can skip this step with a new quality wire set. napa belden wires are good value for good wires. if plugs are too fouled or gap is not in spec, you could be fighting uphill on that or maybe shes floooded and could use some carb spray on them and dry out of cylinders. wire order proper? Its amazing how sometimes you can screw it up or be one off in the right order, just started on the wrong towerr on distributor lol. Pull the coil cover, no damage visible and in good shape? evidene of arcing to the plastic at all?

i remember someone who had a ignition switch issue where the coil wasnt getting consistent power in crank but always had it in key on so it would spark and such but the power was turning on and off and probably couldnt build and collapse as needed to send enough power on each cylinder but would still cross a tester etc

No vacuum leaks? Unplug all the emissions all the extra, you should have one into the pcv valve and brake booster but if you really wanted you can plug those temporary but I would just verify the PCV is ok and if you wanted to plug the brake booster line it would just be easier to verify that one large one to be absent of leaks but you could do the old wrap a little tape around bolt threads and use a flange bolt that fits in hose end to plug it to rule out a failure on that fun stuff

If a auto trans, is the PN switch working right, someone may have rigged some wires here or there and ended up with a present where you have a starter turn but a worn switch or misadjusted etc is cutting ignition power but starter power was provided by alternative routes so it would spin no matter what. been there, sorta. still needed to be out of gear on my car but the antitheft system was designed to prevent starter and fuel injectors without a valid key but someone took the PCM out of the equation for the starter but left the fuel as it was so i could use a key cut for my door that I never programmed to spin the starter but it wouldnt start(fine for me, but when your mom runs your battery dead trying to move your car on a cold morning with your door key... or your diagnostics would normally tell you to look elsehwere if the starter cranks but car doesnt start(because it was designed such the antitheft would not ever fail in that way to allow crank but not start with factiory wiring). Then your truck is much simpler than my car and older too, someone may have gotten ambitious with the old household wire nuts and personalized head scratcher for you down the road.


Im bored and gave way many things to verify but hopefully helps

I remember
 

Raider L

Full Access Member
Joined
Sep 1, 2020
Posts
1,892
Reaction score
994
Location
Shreveport, LA
First Name
William
Truck Year
1974
Truck Model
C10
Engine Size
355
@bonanza1979,

Your coil is dead!!
I had the exact same problem recently and couldn't figure it out, did all you did. So I went on line, put in the problem and it came up coil. I didn't even think about that part. Bought a new coil and I've been going ever since!
 

bonanza1979

Junior Member
Joined
Oct 8, 2021
Posts
4
Reaction score
2
Location
Michigan
First Name
Travis
Truck Year
1979
Truck Model
K10
Engine Size
383
@bonanza1979,

Your coil is dead!!
I had the exact same problem recently and couldn't figure it out, did all you did. So I went on line, put in the problem and it came up coil. I didn't even think about that part. Bought a new coil and I've been going ever since!
Hit it on the head, put a new coil in it and it runs great again. Must just have been getting weak spark. Thanks for the input!
 

Latest posts

Forum statistics

Threads
41,852
Posts
903,529
Members
33,365
Latest member
rossivey
Top