Strange things have been happenin' with my carb...When the car is cold (sitting overnight or whatever) starts up fine, seems to run fine...I take it out for an extrended drive (say 30 miles or so) park it...come back and it's real hard to start...smells like it's running real rich or is floading. So yesterday this happens. I take it to HB from LB(actually only about 15 miles) Have lunch go to head back, real hard to start. Drive home it runs OK, but seems to have a drop in power and bogs down at acceleration. Then stalls about 3 blocks from the house. I get it started again and limp home. So I figure, maybe the idle mixture is too rich, so I follow the proper steps from the Edelbrock manual to lean it out. It won't keep a consistant idle. And when it seems set OK, I take it out for a spin and when I come back and get the tach on it it's way out from what it was set at. So, I check the timing- it's right on. I scratch my head, shut 'er down and go to walk away and read the Edelbrock manual again, and I can smell gas real strong. I pop the air cleaner and I notice there is fuel squirting into the main. I'm running a mechanical pump, so I am quite perplexed at this. This morning I start it, check to see if there is any fuel pumping after shutting it down- nothin' .... Any ideas? Setup: - 283 bored .10 over - Melling Cam (MTC-1) .050 duration- 204 ini./ 214 exh - Edelbrock performer intake and 1406 carb
Could be... Apparently the float bowls on Edelbrocka are notorious for being out of adjustment...Planning on getting to that tonight. I just wanted to see if anyone had a similiar problem before.
Sounds kinda familiar. Obivously if gas is flowing after it's shut off, something is pressurizing it. If the vent is clogged, it will flow out until the bowl is empty. It will also run pretty rich at part throttle. That would cause your starting issue from both sides - A flooded motor as well as a dry bowl.
I'm not sure how old your carb. is or if you went threw it any time soon, but it sounds like the needle & seat is hanging up (not seating) and letting fuel keep filling the bowl. Causes dirty carb., bad float, or do you have a good filter from gas tank. If you run your car low on fuel and theres dirt at the bottom of the tank your going to **** it threw. When car is running rough litely tap on top of carb. near float area if it straightens out, R&R top of carb. and clean out bowl, also good idea to install a fuel filter, at gas tank and close to carb. for best insurance against dirt. Hope this helps, Dave.
A stuck needle won't keep flowing fuel out the mains when the car is off, however. Unless the fuel tank is pressurized (unvented cap). I've had that happen before. Fire. Bad.
By any chance, do you have 3 ports on your mechanical fuel pump? One's in, another feeds the carb, and the smaller is a bleed or return to the gas tank. If this is in an older car where the return's NOT needed, and it's blocked off, i believe that'll be the problem. It's just a slight bit too much pressure when hot, and will push fuel past the needle and seat and flood the motor. Also, try it without the gas cap
Thanks for the replies Fellers... I think Bort62 might be onto something. As a matter of fact, the tank doesn't have a vented cap. This setup is on a T-Bucket with the tank exposed in the rear and I have noticed when cracking the cap on the tank, there is alot of pressure released...Guess I'll get my tank cap venter out... Groucho- Pump has 2 ports (from tank, to carb) I will try without cap first... I got a real good start here...I'll keep ya posted...
I put on a 780 quadrajet, with a ****py adapter, in place of a 750 edelbrock on a air gap intake, and magically, it drove better. Just not a big fan of em now.
Yeah Ive never been too happy with Edelbrocks myself, I always have good luck with Holleys. But everyones has there own preference on carbs.
Burny, I had a non venting cap on the tank in my camaro. As it heated up from driving around (exhaust) and the outside temperature, it would pressurized the tank. This would cause fuel to flow out of it even when the pump wasn't pumping. I went to R&R the carb, and pulled the fuel line. To my surprise, It started spraying gas everywhere. It then caught on fire and I had a mess on my hands. After exhausting two fire extinguishers to no effect I had to reach in with my hand and stick my thumb over the still gushing fuel line. I got it out, and afterwards cracked the tank and it was really pressurized. Long story short - make sure your tank is vented.
I tend to lean more to the side of over pressuring the system. My second thought is heat soaking, whch is not the same as vapor lock, it happens just before vapor lock. Drive the car again and when these symptoms show up open the filler cap on the tank and see what happens, if it gets better you need to work on venting the tank. I had a corvette that had a problem with heat soaking that would push fuel through the boosters in the carb and out of the vents. The way I fixed it was to get an inline fuel filter that had a vent line attachment. I mounted the filter as close to the carb as I could get it and then ran the vent line back to the tank and never had a problem with it again. The filter part numbers are Hastings GF84 5/16 inlet, 5/16 outlet, 1/4 vent Hastings GF102 5/16 in, 5/16 out, 1/4 curved vent, Hastings GF105 5/16 in, 5/16 out 1/4 vent, GF19 5/16 in 5/16 out, 1/4 vent on the end, GF113 3/8 in 3/8 out 1/4 vent.
Any AFB or Edelbrock should be on a one or two inch spacer to keep it away from heat. Try that before condeming the design.
Hadn't heard that before...Still haven't gotten a chance to get out to the garage, but tomorrow I hope to get this figgered...Thanks for all the advice...
My dad tells a story about his '64 Nova that was always leaking gas after a fillup. He put a non-vented cap on it and, as a result, the pump ****ed the tank flat! An old trick we use is running a quart of ATF through the gas tank. I've personally seen sticky floats and other issues magically disappear after doing this. The ATF has a detergent and a lubricant to it, and this helps clean things from the inside. Some will disagree, but as I said, I've seen the magic myself.
O DA LAY AMIGO! When you get the chance to make it out into the garage, let me know so I can bring down the fire extinguishers. I'm here for ya brother.
Well, It definitely seems to be a tank venting problem. This may sound overly simplistic, but can I just "vent" the cap, with a vent maker? (see drill =))
I had the same problem when I ran my Edelbrock then shut it down. When I went to crank it while still hot it was flooded. I installed a 1/2 heat spacer and no problems since. Quick fix for me.
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