HawkZ28

iTrader: (2)

Here's my dilemna.....

During the balmy winter months, I store the Z. I still try and start her and bring her up to operating temperature 2-3 times a month, and drive her IF there is no snow or melted snalt on the ground.

Typically, I start her up, and just let her idle while I'm doing something else in the garage, and get in and vary the RPM's until she's up to temp- then I drive, or just let her run a little while longer, and shut her down.

I've noticed, that when she's been cold for days, she has a miss until the engine get's almost totally warm....and it seems like it's on 2-3 cylinders. I haven't checked the headers yet to see which ones.

After she get's up to temp, she idles, revs, and drives just fine. If I park her, and start her up later in the day (cold), or even a couple days AFTER a good 5-10 mile drive, she starts right up, revs fine, develops a slight miss, and the loses it. It seems as if the plugs are fouling out, and then cleaning themselves......I just filled up with a fresh tank of 91 about 2 weeks ago to eliminate any rchance/risk of summer/bad gas.

The engine has about 3k on a complete rebuild, new cap, rotor, HEI, coil, wires, AC Delco plugs, Thundervolt wires, and I am using a Edelbrock 650 AVS Offroad carb at about 5.5 psi, and haven't had a chance to tweak it with the rod and jet kit I purchased for it, which I *think* might be my issue, but I want to get a second opinion or 2.

THANKS in advance.

johnyIROC

That is completely normal for a car with a big cam.... The larger the overlap in the cam, the lower the vacuum pulled through the intake. When the intake manifold is cold to the touch, the fuel will not atomize correctly, and instead pools up and can cause misfires or no-start.

I took my car (11.5:1 383 with comp XE284H) out in below zero temperature a few years ago and to get it to run, I had to heat up the intake manifold with a propane torch in order to get the fuel to atomize. I run an air-gap style intake, so I put the heat directly under the carb for about 60 seconds and it started and idled just like a perfect summer day. If you have a heated garage, this is likely not an issue.

HawkZ28

iTrader: (2)

Cool beans- THANKS! Now that you mention it, it doesn't have the issue in the summer time nearly as bad.

The garage is heated- but the car has been outside because we've got the stalls filled with stuff for a garage sale next spring, and all of the Christmas stuff and 'stuff we're saving for our next house' that I need to get into the loft, but haven't had time.