Timing problem
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New User
Joined: Aug 2004
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Timing problem
Hey guys, I have an 84 Bronco with a 4.9. It is pinging under load. Ive checked the timing and it is right on spec.
After I set the timing I plugged back in the wire that controls the advance, and the timing mark goes off the scale. Is this normal?
I'm thinking of going to a mechanical advance distributer. Do you know of someone that makes one for the 4.9.
One other question, My Bronco is carborated. Does an EFI intake make a difference. Thanks.
After I set the timing I plugged back in the wire that controls the advance, and the timing mark goes off the scale. Is this normal?
I'm thinking of going to a mechanical advance distributer. Do you know of someone that makes one for the 4.9.
One other question, My Bronco is carborated. Does an EFI intake make a difference. Thanks.
Senior User
Joined: Nov 2003
Posts: 179
Likes: 0
From: Central Virginia
Your timing is controlled by the computer. The computer may be trying to apply too much advance because something is wrong with one or more of its input sensors. I would suggest pulling the codes to see if anything is out of specs on any of the various inputs.
If you decide to replace the ignition with one that has vacuum advance, the Ford DuraSpark II is an excellent choice. If you get a DuraSpark II distributor, wiring harness, and module from a junk yard, it’s a drop-in plug & play modification. I got mine from a local junk yard for $36.
If you install a DuraSpark ignition system, the computer no longer has anything to do with the ignition system and you have the option of replacing the computer feedback carburetor with a non-computer controlled carburetor. There are many carburetor options including after-market manifolds and four barrel carbs. However, those options should be exercised with some caution. Your local emission laws may not allow you to do those modifications.
If you decide to replace the ignition with one that has vacuum advance, the Ford DuraSpark II is an excellent choice. If you get a DuraSpark II distributor, wiring harness, and module from a junk yard, it’s a drop-in plug & play modification. I got mine from a local junk yard for $36.
If you install a DuraSpark ignition system, the computer no longer has anything to do with the ignition system and you have the option of replacing the computer feedback carburetor with a non-computer controlled carburetor. There are many carburetor options including after-market manifolds and four barrel carbs. However, those options should be exercised with some caution. Your local emission laws may not allow you to do those modifications.
Post Fiend
Joined: Jul 2004
Posts: 8,786
Likes: 28
From: Northern California
Originally Posted by Bronco2big
Hey guys, I have an 84 Bronco with a 4.9. It is pinging under load. Ive checked the timing and it is right on spec.
After I set the timing I plugged back in the wire that controls the advance, and the timing mark goes off the scale. Is this normal?
I'm thinking of going to a mechanical advance distributer. Do you know of someone that makes one for the 4.9.
One other question, My Bronco is carborated. Does an EFI intake make a difference. Thanks.
After I set the timing I plugged back in the wire that controls the advance, and the timing mark goes off the scale. Is this normal?
I'm thinking of going to a mechanical advance distributer. Do you know of someone that makes one for the 4.9.
One other question, My Bronco is carborated. Does an EFI intake make a difference. Thanks.
The Carb is caliberated to the distributor so it does this by design, and inbetween the carb and distributor vacume line is a spark retard solonoid, that the computer uses to bleed off the vaccume when the engine shuts off or it senses pinging.
Check and see if your knock sensor is bad.
