Hey all, I bought this car from a friend who thought they had some knowledge of 302 motors. I am finding out that they didn't have much at all about cars in general. With that said I'll explain my problem. I bought a 1984 mustang gt. The car was origanlly a TBI car. He converted to a Carb car. I beleive he used the edelbrock perfromer intake, with a holley 670 cfm street avenger carb. The car had two breathers in the valve covers, I put a pcv valve back in and hooked it to the vacuum side of the carb. The other valve cover is going to be getting a cap put on it. After that, I found my timing to be way off, car wouldn't idle right at all. Pulled distributer and placed crank at 0 at TDC. Reinstalled Distributor and now car actually idles good. I had to set the idle screw to maintain 2000 rpm because when the motor is placed under a load (when I put the car in drive), it drops 1000rpm. Sounds like a Vac. Leak????? Does anyone know what I need to set my timing to? This same guy said he thought 5.0's should be around 14 degrees advanced???? Is that right? Also the car has no smog pump or anything hooked up...I read on Edelbrocks website that I need some sort of adapter for an automatic transmission. Anyone know....My knowledge of cars has always been EFI. I have a cobra and a gt both EFI...This is my first carb car! I need some help. The car will drive ok, but it boggs badly and sounds like it has a miss when I give it a lot of gas. I am guessing that has to be the timing being off.... Let me know!
Does you car have an automatic transmission? If so then it would have came with CFI. The adapter for the automatic was probably for the carburetor kick down for the transmission. The carburetor might be too big too. When I got my 85 GT it had a performer intake and a holley 650 double pumper. The carb was drowning it so I put a 600 on it. As far as the smog pump, forget that it existed unless your state requires it for emissions.
Posts: 700
Joined: 3/31/2007 From: Chandler, Az Status: offline
A couple things I see... You need to put a breather on the valve cover opposite of the PCV. You have an AOD so you'll need a TV cable. Dont drive it till you get it right or you'll cook the trans. http://www.shockley.net/Holley-AOD.asp
12-14* timing is good, depending on the gas quality in your area.
If you have a vacuum advance on your distributor check to make sure it's on manifold vacuum and not port vacuum. I had the same problem on the 79 I picked up a few weeks back. Your base timing should be around 10-12* at sea level and 14-16* at high altitude. With premium fuel you can run a couple extra degrees to get a little better performance. When the advance line is on port vacuum, it will act like it has a vacume leak as soon as you put the car in gear and pull the rpm's down too much. When it's at full throttle it will over advance the timing and cause it to run like crap.
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Carburater and Intake Manifold Help - 
