TrunkMatt Posted June 28, 2011 Share Posted June 28, 2011 EDIT - Originally thought I had Edlebrock... on closer look it is not. Don't ask how I made that mistake... lets just say I am not a mechanic. Hey guys - I have a question on Cold-idle / high idle My nifty new monty seems to not want to go into high-idle on first cold start... seems to be set at 550rpm or so. As a result I have to rest my foot on the pedal to keep it from stalling until she heats up... probably about the first 10 minutes. It can be annoying as it means I need to shift into neutral at a stoplight, and keep the rpm at 850 by foot or risk it stalling, good ole 2 footing etc.... also seems to smell a bit rich until it heats up. If it does stall when cold, it is then a bear to start (first start is fine... stall-out start = complete pain). So to me it means an obvious sign of too much fuel at cold idle, partially flooding. If I make it through the cold cycle, no issues whatsoever. After heating up, all is well... and it actually idles fine, doesn't smell rich. Once it heats up it can idle at its own about 700 rpm with no issues. So, the question is: 1) Is this a choke thing or a float thing, or a high idle speed setting thing? I am not a person who has had the life experience of fiddling with carbs enough to want to take a crack at it without someone experienced thinking it through for me first :-) My only personal reference is my other old car, a 72 Ford Torino with a Windsor 302... and it is VERY DIFFERENT layout than what I am staring at when looking at the Monte. Quote Link to comment Share on other sites More sharing options...
Andreas Posted June 29, 2011 Share Posted June 29, 2011 The high idle timing on an edelbrock is controlled by the choke. The idle speed itself is set by a screw. Which Eddy Carb do you have? See Page 14: http://www.edelbrock.com/automotive_new/misc/tech_center/install/1000/1410_manual.pdf Quote Link to comment Share on other sites More sharing options...
TrunkMatt Posted June 29, 2011 Author Share Posted June 29, 2011 OOPS!!!!- Disregaurd the Edlebrock carb comment... it is actually the standard numbers matched Quadrajet carb, vacuum powered etc... but mounted to Edlebrock Manifold. I assumed it was an edlebrock carb under the filter since it had an edlebrock Manifold... until looking close enough. I am actually quite happy to see this as my car has more numbers matched parts than first thought. Honestly I just got the thing. Anyhow I'll take a few pictures now that I have the filter off. Quote Link to comment Share on other sites More sharing options...
TrunkMatt Posted June 29, 2011 Author Share Posted June 29, 2011 Feeling a bit like a newb (well, I am...) Anyhow, here are Pics of what I have (quadrajet on edlebrock manifold): http://gallery.me.com/matthew.hilla#100049 Thanks in advance for helping me learn. Quote Link to comment Share on other sites More sharing options...
KWick_70MC Posted June 29, 2011 Share Posted June 29, 2011 Matt, see the canister in pix 1119, left of the yellow piece, that is the "heat thermostat" for the choke/high idle. As the car warms up it pulls/pushes the lever to open the choke up and get the idle off the fast idle cam.. when you start the car, you are suppose to push the excelorator pedal down a few times to shoot some gas in the carb, and this also sets the fast idle and choke. When the pedal is pushed to the floor it allows travel for all these parts. The thermostat puls the choke closed, and the fast idle cam to position, and as it heats up, walla it slowley releases it to operating position.. I would have someone do this while you watch under the hood to see if it is setting correctly, and if it is not, check to see if it sets if you hold it open and pull the lever. If it does work correctly, odds are the thermostat is bad or missaligned. I would go with missaligned, unless they are really rusty or just in sad shape, they can be adjusted. Quote Link to comment Share on other sites More sharing options...
TrunkMatt Posted June 29, 2011 Author Share Posted June 29, 2011 Gotchya... I do indeed set the choke when starting - but had no idea this is where the magic happens. I'll wait for the wife to get motivated enough to throw on some outdoor clothes and convince her to help the investigation by sitting in the drivers seat. I suppose I could call her out here in her sleeping gear, but the neighbors are already looking at the car without the extra help. You mentioned alignment / misaligned. Is there a good resource to tell if everything is aligned right here? Quote Link to comment Share on other sites More sharing options...
KWick_70MC Posted June 29, 2011 Share Posted June 29, 2011 The only real way is, as far as I know, is to watch it do it's thing.. you can do by your self by pulling the throtle wide open, and then with the other hand pull the lever at the end of the thermostat and see if it sets right.. Quote Link to comment Share on other sites More sharing options...
TrunkMatt Posted June 29, 2011 Author Share Posted June 29, 2011 excellent, thanks... Quote Link to comment Share on other sites More sharing options...
KWick_70MC Posted June 29, 2011 Share Posted June 29, 2011 http://aarc.epnet.com/autoapp/8668/8668R05_ADJUSTMENTS.htm http://vetteworks.tripod.com/qjet.htm http://www.hotrodhigh.ca/RebuildQjet.html Here are somne good articles, as well as some tech write ups on properly setting things.. Quote Link to comment Share on other sites More sharing options...
wallaby Posted June 29, 2011 Share Posted June 29, 2011 It sounds as if the choke is closing ok when it is cold, but doesn't want to open up as the engine warms. Check the vacuum can (the plastic piece close to your fuel line there) to make sure it is pulling the linkages when the engine is running, or when you put suction from an outside source to it. This is your "choke pull-off", or also called a vacuum break. The choke coil on the intake manifold closes the choke when the engine is cold, and tries to keep it closed...once the engine starts, the vacuum break tries to OPEN the choke. It is the balance between these two mechanisims that determine the actual position of the choke plate. It's kinda like a tug-of-war between the choke coil and the vacuum break, with the choke plate in the middle. As the choke coil on the manifold heats up, it slowly releases its pull and the vacuum break wins out and holds the choke fully open. If the vacuum break has a bad diaphragm, it won't pull as it should and it takes forever for the choke coil to get warm enough to push the choke open. Step one is to check that vacuum break. The other issue is the cold idle speed adjustment. the fast idle screw is tiny and located on the passenger side of the carb. It is kinda wedged down low in the gap between the carb body and the vacuum break assembly...someone probably turned it down so the engine doesn't race at high idle for 10 minutes waiting for the choke coil to open the choke. I think both issues point to a bad vacuum break. Quote Link to comment Share on other sites More sharing options...
TrunkMatt Posted July 2, 2011 Author Share Posted July 2, 2011 Vacuum break did it! I worked it a bit by hand and everything seemed to free up and all is better now. Still need some cold-idle speed work I think, but it is livable. Quote Link to comment Share on other sites More sharing options...
KWick_70MC Posted July 2, 2011 Share Posted July 2, 2011 awesome.. great news.. Quote Link to comment Share on other sites More sharing options...
wallaby Posted July 2, 2011 Share Posted July 2, 2011 Yay! I'm glad you got it fixed; and glad I guessed correctly for once. Quote Link to comment Share on other sites More sharing options...
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