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Attempting to fix idle and set timing


Draker

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I've noticed the idle on my z24 has been a bit high. I adjusted it down to around 800rpm.. seems like everything is okay there. I put a timing light on it and noticed it was WAY advanced. Probably around 15-20BTDC. Looking at the distributor I noticed it was already turned almost all the way counter-clockwise.. I was able to get it adjusted down to maybe 10-12BTDC. The advance seems to work when the RPMs climb..

 

Also seems like the vacuum is low.. about 12hg. I'm guessing I've got a few leaks and will smoke test it.

 

Engine has 139k and to my knowledge the timing cover has never been off the engine. I've got all the service records.. only thing if the timing some how jumped somehow. It's interesting how the distributor is at the end of the adjustment which makes me wonder?

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Are you disconnecting the vacuum advance when adjusting static timing?

I didn't, but I will and try again.

Pull the vacuum advance hose off and check the advance.

 

Wiggle the rotor, perhaps the mechanical advance is stuck advanced slightly.

Will do! Does it seem weird that the discributor is clocked all the way to one side though? That's the way it was when I bought it.

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There shouldn't be any vacuum advance at idle if the throttle plate is closed properly.

 

 

Will do! Does it seem weird that the discributor is clocked all the way to one side though? That's the way it was when I bought it.

 

Well that's wrong right there. To check... set to TDC and lift the dizzy out. The drive spindle should be at 11:28 like this...

 

distributortiming.jpg

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Thanks, I'll take a look at that as well. I pulled the dizzy out yesterday hoping I would find a gear on the end of it.. thinking it might have been off a tooth and that someone may have installed it wrong. I'll dig a bit deeper and take a few pictures. Might be a few days though before I can tear into it again. I'll post back.

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I am also in the same boat. My distributor is cranked all the way to one side, and it's all I can do to get 3 or 4 degrees initial timing with the advance unhooked. Looks like I got some work to do this week.

Even if I have it cranked to one side, I can get to maybe 5-8 BTDC..

 

I smoke tested it to check for vacuum leaks, everything seemed okay. Noticed the vacuum lines were all in poor shape though being 28 years old. Going to go through and replace them all while im in there.

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I had the same issue. You have to pull the oil pump and rotate the drive gear one spline to make the gear more straight upand down. mine had to be at 12 o clock to be able to adjust it perfect. Just make sure the small lobe is facing is facing the front of the engine. Once that is set then you can use the timing light and set it to 3 btdc. I'm pretty sure that's what the spec is. Pulling the oil pump is super easy so don't stress. Takes like 10 min.

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I had the same issue. You have to pull the oil pump and rotate the drive gear one spline to make the gear more straight upand down. mine had to be at 12 o clock to be able to adjust it perfect. Just make sure the small lobe is facing is facing the front of the engine. Once that is set then you can use the timing light and set it to 3 btdc. I'm pretty sure that's what the spec is. Pulling the oil pump is super easy so don't stress. Takes like 10 min.

 

I will definitely look into doing this. Thanks for the tip! Probably put together wrong a decade ago by some tech.

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