timing for rough idle
10-05-2024, 05:44 AM
#1
timing for rough idle
I need to inspect and adjust the timing on my 94 pickup that is currently suffering a rough idle. It is bad enough that I usually creep up to red lights to minimize time spent stopped. Along with this will be new spark plugs as it has been too long since they were replaced. My question is whether I need a basic or more sophisticated timing light for this job. Reason being is the sticker under the hood shows 10 deg stock adjustment. However the marks next to the crank shaft pulley are 5 / 8 / 12, not a mark at 10 deg. In this case do I need a timing light that can be programmed for 10 deg so that I can align the mark with 0 deg?
Although it could require a different remedy to address the rough idle, would the stock timing be the recommended adjustment, or would slightly advanced or retarded usually help with this condition? Of course I will test this out in the moment, although would like to know any empirical or theoretical basis for timing as it may pertain to a rough idle.
Although it could require a different remedy to address the rough idle, would the stock timing be the recommended adjustment, or would slightly advanced or retarded usually help with this condition? Of course I will test this out in the moment, although would like to know any empirical or theoretical basis for timing as it may pertain to a rough idle.
10-05-2024, 07:45 AM
#2
Registered User
Ignition timing "shouldn't" cause a rough idle unless it's pretty far off. My 22RE's have all seemed to run a little better with a couple more degrees of advance but, it never got "rough" when advanced or retarded a few degrees.
Too retarded and it has to crank a long time to start and it will buck if too advanced. It will idle high when advanced too far and knock under load.
My son had a 91 that would randomly get a rough idle and miss. It would go away if he wiggled the wiring harness with the injector wiring. He finally unwrapped the harness and found cracked insulation and damaged wires. Some were broken and only had a couple strands hanging on.
A basic timing light will get you by. A dial back type is more handy though. Maybe you can rent one??
Cheapie spark plug wires can cause problems. I never had any issues with OEM or NGK wires. I also never had problems with OEM or Denso caps and rotors. I ran Accel USA made ones that were high quality as well. NGK or Denso spark plugs are a personal favorite. Just my personal experience and opinion here.
Good luck, I hope you get it figured out. I know it can be frustrating but don't give up.
Too retarded and it has to crank a long time to start and it will buck if too advanced. It will idle high when advanced too far and knock under load.
My son had a 91 that would randomly get a rough idle and miss. It would go away if he wiggled the wiring harness with the injector wiring. He finally unwrapped the harness and found cracked insulation and damaged wires. Some were broken and only had a couple strands hanging on.
A basic timing light will get you by. A dial back type is more handy though. Maybe you can rent one??
Cheapie spark plug wires can cause problems. I never had any issues with OEM or NGK wires. I also never had problems with OEM or Denso caps and rotors. I ran Accel USA made ones that were high quality as well. NGK or Denso spark plugs are a personal favorite. Just my personal experience and opinion here.
Good luck, I hope you get it figured out. I know it can be frustrating but don't give up.
The following users liked this post:
Jimkola (10-05-2024)
Thread
Thread Starter
Forum
Replies
Last Post
