Is this vaporlock or what?

[Syco67]

69 GMC 3/4 2wd, 350-4bbl/4spd. In the begining the the truck would hesitate, after sitting in traffic too long. We figured vaporlock. We have added a spacer, replaced the carb,(edelbrock 600) replaced and rerouted the fuel line, replaced all the filters, pump is new, fuel pressure was excellent, adjusted points/timing/dwell, even took apart the new carb to verify it was clean. The truck never overheats, gauge has never even gone halfway up. Nothing has changed. If you run the truck for a while and shut it down, and let it sit for a few minutes, it is almost impossible to restart, and when you give it gas, you can hear it just sucking air. It sounds like it's not getting gas. Have I missed anything?

[Gordo]

Sounds like it's flooding, what is excellant fuel pressure? Maybe it's too much pressure and it's pushing fuel passed the needle and seat.

[Cat Fuzz]

Float level adjusted properly? Maybe you need a heat shield in addition to the spacer.

[chickenwing]

Think Gordo is hitting on it with the fuel pressure. Edelbrock recommends 5.5psi with no more than 6psi.

[Syco67]

Fuel pressure was 8psi. But it is a stock replacement pump. Wouldn't the engine bog if it was flooding? It's not blowing black smoke or anything. It makes a dry sucking sound when you hit the throttle. Carb floats were fine too.

[Cat Fuzz]

Try adjusting the accelerator pump. You might have two different problems.

[Syco67]

Do you think I should get a pressure regulator? Set to 5psi? Where should I set the accelerator pump? It has 3 settings, it was on the middle setting, but I put the rod in the hole closest to the carb, that would result in more gas right? Sorry about all the questions, I can disassemble and reassemble almost anything, but can't adjust anything to save my own life.

[tnblazerk5]

wait just a min if its doing this

It makes a dry sucking sound when you hit the throttle

it might be a vacume leak sumwhere

[Syco67]

The sound is coming from the carb, but I did do the carb cleaner test to be safe and found no leaks.

[tnblazerk5]

did ya check around the intake too? and all the hoses ?

[Syco67]

yeah, couldn't find a leak, but the engine is a lot cleaner.

[tnblazerk5]

clean hehehe is good ok if ya think its not getting enough gas start lookin at the gas lines themselfs, once mine had a bad clamp but it didnt leak gas out it leaked air in ( it sucked air in around the hose )it would run good most the time and then all at once would die and it was a mother to get started back

[Syco67]

I will take a look at that, with 3 tanks, there are plenty of hoses and clamps to go bad. May as well replace all the rubber under there anyhow.

[Longhorn Man]

The odds of havin vapor lock in you location at this time of year is pretty much nill.
have you messed with the fuel to air ratio at all

[72MARIO]

[/QUOTE]Where should I set the accelerator pump? It has 3 settings, it was on the middle setting, but I put the rod in the hole closest to the carb, that would result in more gas right?[QUOTE]

The hole closest to the carb would give it the smallest squrit. Because there is not as much travel. By putting the rod in the whole at the other end you would get the biggiest squirt. If you know you have 8 Psi thats way too much and it needs fule pressure to be set at 5 Psi.

[Maximum Overdrive]

How is the choke. I had one that would screw up after running for a while and make it hard to restart.

[flip66]

just want to watch this tread

[Syco67]

I know the temp is too cold, and I haven't had any problems, but I am sure it will come back next summer, and am trying to check everything I can to hopefully fix it by then. I just won't know what worked until then. Had another problem yesterday, had a radiator tube blow out and hose me with coolant after I replaced the pump. Now I need to spend $300 on a new 4 row radiator.
I will reset the accelerator pump, and get a fp regulator as soon as I can.

[Huck]

For your radiator--go on-line. There are several places that will sell you a 4 core for a lot less then $300. delivered to your door with a lifetime warranty.

I had hard starting / stalling problems on my 71. Replaced the HEI distributor module and condenser and the problem went away. Would only happen when the truck was good and warm or very damp out.

If the truck seems like it is starving for gas, take the air cleaner off and look down the carb (not running!!!). Now pull the accelerator and see it you get the "squert" more then likely, that's not the problem. That would only apply to acceleration---not idle. I tend to go with GORDO on most things as he seems to forget more then I know!hehehehe