Intermittent miss

[mryan60]

This has gone on for the past couple of years. I will be riding along on my 1985 Limited and it will start missing, mostly on acceleration. Usually when I back off on the throttle, the miss goes away and it runs smoothly, but not all the time. Sometimes the problem cam last the whole ride or just show up for a few minutes. Fuel filter has been changed. Any suggestions. Thanks in advance and ride safe!

[ct1500]

Fuel injected, right? Any codes showing? Just because of the age I would prolly start with plugs, wires and maybe coils, nothing lasts forever and if never done I think you got your moneys worth out of them. Are these the ones known for pulse generator problems?

[mryan60]

Yes, fuel injection, plugs have been replaced, wires have been checked (hard to find replacement but would love a new set) replaced coils. Running with a poor boy alternator and I replaced the rectifier.

[mryan60]

Yes, fuel injection, plugs have been replaced, wires have been checked (hard to find replacement but would love a new set) replaced coils. Running with a poor boy alternator and I replaced the rectifier. And no codes

[ct1500]

Wires have been checked??? Not good enough to simply look or OHM them. Back in the day it often took a scope with the engine under a load to find bad/poor/misfiring wires. Remember, 35yrs. of age. Replace those so they can be eliminated as the cause.

[mryan60]

A mechanic had the old setup that plugs onto the wire and the plug then measures the strength of the spark. Sorry, I should have elaborated. Could the throttle body sensor have that effect?

[ct1500]

That set-up cannot test with the engine under a load which is when your problem appears and occurs. Simple/likely things first. When this happens can you pull off the road and is the engine still missing at an idle?

[mryan60]

I took it for a long way yesterday and it nevermessed up once. Next time it happens, I will pull over like you suggested and pay attention to what it does