Hi Guy's, I need some advice. I have a 50 Chevy with a 305/700r4 combo. The engine is rebuilt and came originally out of a 86 Camaro with tpi. I removed the Tpi setup but still ran the in tank pump. The car was always a pain to start. I have now changed to a manual fuel pump. The carb is an Edelbrock 600 with electric choke. The car will only start if I pour a little gas down the carb, once its running it's fine although it does smell like it's running rich. Looking for suggestions, timing is correct and I have driven it a couple of miles but have had it stall out on me in the past and was a bitch to start again. Thanks, Alex
The TPI fuel pump would have put out way too much pressure for a carb setup. This may seem off the wall, but check to make sure float/arm/needle isn't damaged that it may be allowing fuel to enter the carb. At the very least, check your float setting. Edelbrocks like low fuel pressure.
I was using a special pressure regulator with the return line to the tank, it dropped the fuel pressure down to 7 PSI forgot to mention that on the original setup. Since ditched that whole setup and now using a speedway manual pump, new gas tank and fuel line.
Okay. Edelbrock's instructions recommend no more than 6.5. Check your float and pressure settings, even stock pumps can have high(7-9 psi) pressure. Try to get it 4.5 to 5. It's worked for me.
had a lot of trouble with Edelbrocks cooking off the fuel and flooding out on a hot restart, spacers and insulaters do that problem best also i usuall run about 4 psi on them
Thanks the fuel pressure rating on the speedway pump is 7 psi so that could be it. I am going to get a 4 psi regulator and see if that will fix the problem.
set fuel pressure to 5 and a half with regulator or edelbrock pump (summits brand might be edelbrock, not sure). I just did this, if i did it again id just buy their stupid pump and be done, pita to re route and re plumb everything.
The AFB types are sensitive to fuel pressure, but that doesn't explain your needing to prime it for starting. It's likely that your idle mixture is a bit lean, but it should still start with a tap of the pedal, unless your accelerator pump shot is too short. Look at the position of the pump link on the lever and move it for a longer stroke. Turn the mixture screws a half turn richer, then adjust with a vacuum gauge for highest idle, lower the rpm, adjuste for highest idle, repeat until you just can't lower the rpm any further. Tuning these is fun, but it shouldn't be far off for a 305. Unless you added a cam, though, a 500 cfm version is probably more appropriate.
Fuel pressure is critical as mentioned but I would also make sure you don't have vacuum leak or contaminated gas. Make sure you run a quality fuel filter. If it's a new carb don't assume it was assembled correctly. I had build issues with a new Edelbrock that I installed a few months ago where the throttle plates where loose and the float level was too high. I could never get it to idle correctly or start on the first try. After I dialed it in it runs perfectly. If your carb is older you might want to check the needle and seat. We have ethenol in the gas in my area and it is not good for some older rubber hoses or the older carb rubber tipped needles.
yeah 600cfm is HUGE for a 305... i remember the calculations for a 318 at 5k max rpm was a little over 500...
No one mentioned if your choke is closing completely when cold. Those electric chokes work well, but they must be adjusted to completely close when you open the throttle, then when it starts, the choke unloader opens the butterfly a little to run properly. Carl
I have that same set up in my 49 ford. I have a manual pumptoo. when i installed mine it didn't want to run right either. took it to a friend's shop and he played with the jetting and a maybe a needle setting been fine ever since. also set the timing. I know he mentioned my carb was a little lean it's a edelbrock 1406 i think it's supposed to be a fuel economy 600.
Engine has an RV cam, the carb model is a 1406. I use to play with Camaro's quite a bit and this model carb is used a lot when changing ov from tbi to carb.
Check the pump shot make sure its squirting when you pump the gas.Also take the top off and see if there trash in it.I have found this to be the problem most of the time.Filters only stop so much.If it gets sand or dirt or rust particles in it It's not gonna work right. Hope this helps.
Although a 500 would be a better choice for a 305, being a 600 has NOTHING to do with it not starting. It sounds to me like there is an issue with the accelerator pump. When it doesn't want to start, take the air cleaner off and flick the throttle - you should see fuel squirt into the primaries. If not, either your fuel level is too low or there is a problem with the accelerator pump itself. Adjust the fuel level per Edelbrock's instructions and see if you don't cure it.
you alredy know about getting the fuel pressure down. that's #1 with these. #2 is setting the float height. sounds to me that the floats are too high and it's flooding from that. Then, when you shut it off hot, it's perculating the fuel and it's too rich to restart until it cleans itself out. The priming issue might be perculating related, too. I'd been sucessful with 1/8 inch lower float settings on a 1406 i had. Electric choke needs to be on a 12V line. taking it off the coil, if that's what you have, isn't gonna work right. Edelbrock has a good downloadable and printable instruction sheet on their website. It has a lot of really good info.
Well it looks like it was fuel pressure and a vacuum leak. I bought a Mr Gasket fuel regulator and set it to 4 psi. While I was at it I checked my vacuum lines, the one I had going to the dizzy was a line with stainless braiding over it, ends up the rubber hose was not fully seated. Car now starts straight up and idles perfectly and no more rich smell. I have yet to drive it again as my 40 pickup is in the way. Got some tires for the truck at local swap meet today so should be able to move that out of the way by next weekend.
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