Hi everyone,
Great Board, BTW!!

If anyone can help...

I have a recently purchased 85 Z28, it's got a 5.7L 350, RV Cam, holley 4160 4bbl carb.

I took the carb out to clean and reset everything the previous guy tinkered with and I'm noticing a couple of problems.

1. the electric choke is not working. It's got 12v going to it and proper ground but when I turn on ignition it doesn't open up. Any suggestions?
It's super hard to start-up in the morning without a few pumps on the pedal and then holding it down slightly until it warms.

2. I'm playing with float settings, the manual says that fuel should just trickle out the side holes when running correctly, is that right? So far there is fuel coming out when I check it and acceleration seems pretty good but mid-throttle is a bit flat. I adjusted the air/mix screws to 2 turns out.

I still need to get the plugs changed and give it an overall fluid change.

Thanks guys.

 

Yes the fuel bowl level should be just at the bottom of the holes, so it sounds like you've got it there or a little high.

How does it run for rich/lean etc? have you checked the plugs etc? I'd make sure that you have good plugs and plug leads before you look too much into the carb being an issue.

What jets are you running? I've just moved mine from the stock 66/67(well 134-9) down to 64/65.

As for the choke, I can't help you there, as ,mine has been removed by the previous owner. It is still easy to start even on cold days. Just have to pump the gas twice, set the fast idle to 1,500 and hold it on the starter until it fires on multiple cylinders. starts first time every time. It didn't used to but new plugs, leads and setting the timing right get it there.

Once its warm I run a 550rpm idle so until its warm you do need to hold a faster idle or it will die.

Si. :lala:

ps. Once the engine is warm, tune the idle mix on both sides for maximum engine speed. I did this and then used a wideband O2 sensor to get it running at stoic. (don't ask)

 

Make sure the polarity of the coil is correct- power to the +, ground to the -. Hooking it up wrong won't work. Also, be sure you're ACTUALLY getting 12V to the choke as installed on the engine. Actually test the voltage with the engine running and the choke hooked up. If it's not holding 12V at the terminals it's possible you've got a weak power source for the coil that isn't keeping up for some reason. Also, might try to play with the choke adjustment a little. Too much one way or the other and it'll either never pull the choke closed or never open up. Beyond that sounds like the choke element is dead and needs replacement.

Original stock specs for your carb can be found in a PDF file you can dowload off Holley's website. I always start from stock and tune from there.

 

Thanks guys,

I gave it a tune-up and it fired right up!!
Plugs were black and the carb was way too rich. I reset to holley specs and seems to work.
Excellent.

BUT!!
I'm getting a progressively louder "high pitch whirring" sound from what seems to be the distributor. It does it after the engine warms up.

Any ideas on this one??

 

Me again,

Upon further research I'm sure it's the distributor bushing.
Out she comes...