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Discussion Starter · #1 ·
Hi,
I have a recently rebuilt (<1000 miles) 289 with a mild cam.
Holley 289 performer 4 bbl intake with a Holley 4160 with electric choke.

Everything was working fine until recently. The problem I now have is:

When I start her from cold - she starts right up and idles at 1200rpm
with the electric choke engaged. There's quite a bit of white smoke.
She idles like this nicely for about a minute and a half and then starts to get really rough with the white smoke being replaced with black smoke.
After 30 seconds of this (and quite a bit of black residue on the ground from the exhaust) she cuts out.

To troubleshoot I've:
- Replaced power control valve
- Cleaned out the idle circuits in the metering block
- Dry and then wet adjusted both floats
- Tune the idle mixture screws (with vacuum gauge)

There are no problems at all once she's warm. Idles nicely with
no smoke.

Also there was gas in the oil on the last oil change (so I supected
the floats).

It seems to be a choke problem - but I can see the choke
plate coming off (opening) within a minute or two of starting
the engine from cold.
By the time the black smoke and rough idle comes - the fast idle
cam is still engaged but the choke plate is well open.

I really though it was the power valve. Now I'm stumped.
Any ideas?

Thanks!
 

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you will prob have to adjust the choke. I had to do it on mine. Look on Holleys website for instructions, they should have a users manual.
 

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I agree with astumpf, retrieve the choke instructions from Holley's web site and follow them to the "T". If the fast idle cam is still engaged and the choke plate is wide open, there is something wrong with the choke linkage setup.

As you probably already know, white smoke is an indication of water and black, fuel. I hope the white smoke is just condensation and not a head gasket problem. Is the engine coolant level staying where it should or are you having to add coolant frequently?

I don't use the choke on my carb. and I have an auto trans. Even when it's cold outside, all I do is to feather the throttle and let the engine slightly come up to temp. before placing in gear. What I'm trying to say is to disconnect the choke and secure the choke plate wide open to see what happens. See what kind of smoke is being emitted.

As for the gas in the oil, could be the fact that fuel is getting past the rings. Try doing a compression and leak down test while the engine is cold. Have you been experiencing any sticking float problems?
 
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