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Discussion Starter · #1 ·
Pardon my ignorance regarding the fine points of tuning an engine. I should be better educated about these things seeing as how I just rebuilt the **** thing! I've been driving my car in circles around my neighborhood here in Phoenix since I don't have it licensed, inspected or insured yet (neighbors must luv me), and I notice that it stumbles, stuttering and light backfiring out of one or two cyl when accelerating from idle up to about 4,000 rpm and then just takes off like a bat out of ****. I haven't gone over 4,500 rpm yet because it's so fresh, it also seems to do the same thing hot or cold and load or no load. I suspect that it's idling a little rough too.

Could it be timing? I put a timing light on my engine last night and it reads 11deg on the scale by the pulley. I was wondering if this should be set to 5deg or what the heck to do with it? The vaccum advance hose is hooked up to the charcoal canister and also Y's off to the BCDD. Is this the correct configuration for that hose? And when does the vaccum advance work? Does that pull it back to the 5deg mentioned in Haynes?

Thanks

Steve Graber
 

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Check Your Plugs

Steve,
Pull a couple of your plugs and check the color:
Black - too rich
Light tan - just right
eggshell white - too lean
sounds like you might be running lean. If so you need to R&R your throttle switch and AFM. Got to have an exhaust gas analyzer to do it right which means a mechanic - hope you know a good one.
Phantom
 

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Discussion Starter · #3 ·
Re: Check Your Plugs

> Steve,
> Pull a couple of your plugs and check the
> color:
> Black - too rich
> Light tan - just right
> eggshell white - too lean
> sounds like you might be running lean. If so
> you need to R&R your throttle switch and
> AFM. Got to have an exhaust gas analyzer to
> do it right which means a mechanic - hope
> you know a good one.
> Phantom

I pulled #1 plug wire this morning and the engine doesn't change. When I pull #2 I can notice a slight diff. Pulling all the rest (one at a time) really stumbles the engine. So maybe #1 and #2 injectors are clogged? I checked the wires for spark and they are all sparking nicely. My timing is at 10deg, timing advance is working properly, and the injectors are all clicking.

How does the TPS come into play with this problem? Luckily I just found a mechanic close by that has been working on Z since '69 when the fairlaidy came out.

Steve G
 

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Re: Check Your Plugs

Steve,
What I meant by check your plugs was to look at the color of the tips. Black in color and you're running too rich, eggshell white - too lean, light tan - just right.
The TPS can affect your running if it is misadjusted where it doesn't allow you to drop back to the idle position. That way the car is always running rich at low speed. The AFM, of course, can be misadjusted to allow you to run either rich or lean. Get the local Z mechanic to talk you through all the stuff that will affect the engine. Be sure you have about an hour to just listen.
Phantom
 
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