Won't Start with Afterfire; ideas?
Thread Starter
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 79
From: Monroe OH
NCM Sinkhole Donor
Won't Start with Afterfire; ideas?
I am going to start diagnostics this evening but wanted to see if anyone had any ideas from a similar scenario.
We were running the car at an autox event and all was running good. We started to get a little sputter in a couple corners; which is typical if we get low on fuel. On the last run I took the car around a sharp corner and when coming out went back on the throttle and the car after fired and wouldn't start back up. I actually thought it had probably ran out of gas. We put more fuel in and the car will crank, but will not start. If I push down on throttle any at all it will after fire, pop in the exhaust. I was short on time Sat evening after getting it home and tried to install another fuel pump in hopes this would be the issue. It was not. Car still will not start. Yesterday evening I pulled codes from ECM and just got code 12. However, I did notice for the first time that the odometer was at 0. This is the first time I have ever seen this. Not sure if this is related to the no start or not?? I know this is probably a fuel or ignition issue but if anyone has any ideas or has had this same scenario happen please chime in. Thank you.
We were running the car at an autox event and all was running good. We started to get a little sputter in a couple corners; which is typical if we get low on fuel. On the last run I took the car around a sharp corner and when coming out went back on the throttle and the car after fired and wouldn't start back up. I actually thought it had probably ran out of gas. We put more fuel in and the car will crank, but will not start. If I push down on throttle any at all it will after fire, pop in the exhaust. I was short on time Sat evening after getting it home and tried to install another fuel pump in hopes this would be the issue. It was not. Car still will not start. Yesterday evening I pulled codes from ECM and just got code 12. However, I did notice for the first time that the odometer was at 0. This is the first time I have ever seen this. Not sure if this is related to the no start or not?? I know this is probably a fuel or ignition issue but if anyone has any ideas or has had this same scenario happen please chime in. Thank you.
Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,074
From: Lansing MI
I couldn't speak intelligently about a modified car since anything is possible. However I can tell you that the majority of opti spark distributor problems I have encountered have behaved pretty much exactly like what you have described. It begins with erratic operation hot, and ends in a no start accompanied by back firing.
Thread Starter
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 79
From: Monroe OH
NCM Sinkhole Donor
I couldn't speak intelligently about a modified car since anything is possible. However I can tell you that the majority of opti spark distributor problems I have encountered have behaved pretty much exactly like what you have described. It begins with erratic operation hot, and ends in a no start accompanied by back firing.
For reference; I do have a larger displacement engine and modified intake, but I still use the stock ECM and HEI Distributor.
Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,074
From: Lansing MI
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
I am going to start diagnostics this evening but wanted to see if anyone had any ideas from a similar scenario.
We were running the car at an autox event and all was running good. We started to get a little sputter in a couple corners; which is typical if we get low on fuel. On the last run I took the car around a sharp corner and when coming out went back on the throttle and the car after fired and wouldn't start back up. I actually thought it had probably ran out of gas. We put more fuel in and the car will crank, but will not start. If I push down on throttle any at all it will after fire, pop in the exhaust. I was short on time Sat evening after getting it home and tried to install another fuel pump in hopes this would be the issue. It was not. Car still will not start. Yesterday evening I pulled codes from ECM and just got code 12. However, I did notice for the first time that the odometer was at 0. This is the first time I have ever seen this. Not sure if this is related to the no start or not?? I know this is probably a fuel or ignition issue but if anyone has any ideas or has had this same scenario happen please chime in. Thank you.
We were running the car at an autox event and all was running good. We started to get a little sputter in a couple corners; which is typical if we get low on fuel. On the last run I took the car around a sharp corner and when coming out went back on the throttle and the car after fired and wouldn't start back up. I actually thought it had probably ran out of gas. We put more fuel in and the car will crank, but will not start. If I push down on throttle any at all it will after fire, pop in the exhaust. I was short on time Sat evening after getting it home and tried to install another fuel pump in hopes this would be the issue. It was not. Car still will not start. Yesterday evening I pulled codes from ECM and just got code 12. However, I did notice for the first time that the odometer was at 0. This is the first time I have ever seen this. Not sure if this is related to the no start or not?? I know this is probably a fuel or ignition issue but if anyone has any ideas or has had this same scenario happen please chime in. Thank you.
It sounds like an ignition problem, check for spark and then go from there.
Thread Starter
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 79
From: Monroe OH
NCM Sinkhole Donor
Started diagnosis and check fuel pressure first and it was good. Next, pulled distributor cap and JACKPOT, see Picts. I am going to try to represent the button and cap first and if have any issue I will replace complete distributor. 👍
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Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,074
From: Lansing MI
If the issue is as plain as a loose rotor screw then problem solved. If not then I would pull the distributor and make sure there's no slop in the shaft bushing and that it spins freely....
Team Owner
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
OP - your HEI harness(s) to the internals appears to be in excellent condition. The insulators/grommets to the housing seem to be 100%. That's becoming more rare and requires something less than a desirable appearance option to correct. Confirm the housing, distributor shaft relationship and repair yours. Housings, shafts or actually complete used distributors should likely be in all of the local swap bazaars or CL postings.
You might find a donor here in the parts section.
Time for the later small cap conversion? Maybe!
You might find a donor here in the parts section.
Time for the later small cap conversion? Maybe!
Thread Starter
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 79
From: Monroe OH
NCM Sinkhole Donor
When I pulled the distributor cap off, both screws for the rotor button were out. My theory is that the screws backed out over time and all the vibration and forces the car gets exposed to while racing. Visual inspection of the components in the distributor itself look fine. I am just going to replace the rotor and cap for now. And for the screws on the rotor, I may put just a little silicon on them just to help secure them and help prevent them loosening up.
Thread Starter
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 79
From: Monroe OH
NCM Sinkhole Donor
Got it all back together and fired right up😄. I did take note that the rotor hold down screws have washers but not lock washers. So, I put thread sealer on them to help them resist vibration and help prevent against gailing. And one other thing is that my odometer came back to the actual mileage after running for about 30 seconds. Hopefully this will help someone in the future with similar issue.