I've been running the same combo on a 302 for the past 4-5 years. Edelbrock 1406 / Edelbrock 1 inch phenolic 4 hole spacer / Weiand Xcelerator Intake. I drive the truck everday and have always been able to come out, turn the key, and it starts right up and idles nicely. For the past month or so tho... I have to pump the pedal a couple times to get it started and until it warms to operating temperature it idles rough and low. Once it warms up it seems to idle fine and runs good. I've checked for vacuum leaks at the mounting gasket, intake, and replaced the modulator valve hose and hose running from the intake to trans. The idle screws were set with my timing light (it has digital rpm gauge) I turn each screw in one at a time and then back them out until I get the highest rpm. There are no vacuum leaks I can find and the compression is 170 / 175 on all cylinders. I adjusted both float bowls to 7/16 & carb cleaned every orfice I can find. Any ideas? It's driving me nuts trying to figure this out! Thanks in advance! Mike PS should my electric choke be coming in to play at all even in warm weather? I know it's meant for cold weather, but does it also come into play when your start the engine "cold"?
Maybe. You might have burnt the bi-metal electric choke mechanism and it is not functioning properly. Could make a difference even in warmer weather.
After 4-5 years of ac***ulating crud in the bowls etc it is time to go thru your carb and 'put a kit' in it. An edelbrock doesn't need much to clean them out, they are very easy to work on. In your case I'd focus on the idle circuit p***age from the idle restrictor over and down to the idle richness screw. That p***age is made with 2 drilling operations and takes a plug (just above the screw) to seal it. At that plug is where trash will ac***ulate, its a little restrictive pocket. You can clean it by spraying down from the top where the idle circuit starts and holding your finger over the idle richness screw hole and that forces the spray out the transition and idle discharge holes. If you can't get fluid out of those holes then you have to pull that plug out, clean and reinstall the plug - it'll seal no worries.
Take off the air cleaner so you can see the choke ****erfly then work the throttle linkage to full and let go. The choke ****erfly should close. If it doesn't you need to check the linkage for binding and the choke adjustment. To check the choke element turn the key "on" and read the voltage at the choke wire connection.. If you have 12VDC and it doesn't close the ****erfly then either the bimetal spring is broken or frozen. Take the three little screws off and take a look.
Yes the choke comes to play, Be the engine 30* or 90* its still needs 100 more degrees and a rich mixture and high idle to get started and gain temp. The pumping your doing is dumping extra fuel via the accelerator pump. The low idle is probably because its not on the fast idle cam. BTW, 4-5 years is way past new. Or is it a new question?
My experience with carburetors in general... They all have very small air and fuel p***ages in them. The idlefuel, the high speed transfer and the low speed transfer. I doubt anything in the bowls is effecting the starting or the idle. They just dont work together at that point. BUT, the idle screws and the other bleed holes (two each at both the booster venturys) will need a proper cleaning out. Sounds like one or more of those "small" p***ages has a partial blockage. A good p***age cleaning and an air pressure "blow" dry inside each p***age seems to be in order. Mike
Thanks for all of the replies! I ended up buying the rebuild kit and rebuilding the whole thing, but the choke was the main culprit... It wasn't closing do to the extreme heat we've had here in Florida lately. Between re adjusting the choke and throwing a rebuild kit in it, she's good as new! (Well close enough for me anyway) Thank's again for all the replies! Mike
New question! (As far as I could tell searching for weeks on the Internet) lol thanks for the advice! Mike
Maybe check the vacuum break/choke pull-off as well. If it's failed or out of adjustment it could cause a too-rich condition immediately after a cold start.
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