[Orndorff8908]

I'm sure this same thing has been posted a million and one times...And it's just a stab in the dark but 'ere goes. I put a rebuilt 302 in my '68. Ran it out of the car and it ran perfect. Put it in the car, and it ran peerrrfect. I cut the fuel line (back when it had the inline 6 in it) and put a clear plastic inline fuel filter in it. Also rebuilt the carb. Well the other day I took it to sweep it out, and it would turn over fine but wouldn't start and it drained my battery. (had it tested good battery, good charging, good alternator) I had just put a new fuel pump on it and figured that was it. And it did fix it. Went to cruise it to the gas station (10 miles away) and ran fine until the ride back. I had to keep mashing the pedal to keep it from dying. And it died on the side of the road. Had to let it sit for a second before it would start and it kept lunging all the way home. Even with the pedal smashed. So I replaced the carb fuel filter and the inline one, as well as another fuel pump. And brand new points and condenser. Well today I went to drive it and it did the same thing. I did notice that when it would die or shut off, the clear fuel filter would empty out really fast. So I messed with the choke a bit. And then it kept it filled up. Also though, when the choke is opened all the way even after it's warm it kills it almost instantly. Every time. So I messed with the choke, and it sounded good. Took it out of town, and saaaaame thing. When I cruise it around town it's perfect (sometimes, it kinda does even at that speed but not as bad). Drive it at 55-60 for a few minutes and it starts doing it again. So I either have to feather it or mash it to keep it from dying. And when I come to a complete stop or start to slow down, it acts like it's starving for fuel. So when I stop, I have to keep the gas pedal pushed down just a little bit to keep it from dying. The fuel filter is completely filled and has crystal clear gas in it. It ran like brand new until it's little episode after I swept it out. Turn the key, no hesitation and it would fire and go. Only thing out of the ordinary that I did was put a bottle of Lucas in it. But the problem didn't start for awhile after that. And I drive it a few days a week or at least start it and let it run for a bit. Now the only time it runs smooth is when it's in park or slowly cruising it around 25-40. It even dies sometimes just at idle in park lately. Everything on this motor is brand new. One last thing, when I try to keep it running in park, I mash the gas and it doesn't actually backfire, but it does crack a bit. Just has me stumped. Anyone with anything would be greatly appreciated. Thanks alot guys! Drive safe!

 

[Print Dad]

Hello Orndorff8908,
Before I try to help - I would like to offer a bit of advice
"slow it down a little" What do I mean by that? Well you are
jumping all over on this and I fully understand that. I was young once LOL

OK with that out of the way now for the important stuff.

FIRST - -what type of carb are you running and do you know the cfm's?
It is OK if you don't know.

You mention a LOT of things in the post and I would like to address a few of them.
Please understand - -I am trying to help you.

You mention new points and condensor - -BUT have you checked the dwell?
Or a least double checked the gap - - - -Honestly I doubt your issue is elctrical
sure sounds like a FUEL issue.

Next - -the choke will have nothing to do with gas staying in the "clear" filter.
let me explain - -the purpose of the choke is to cut back on the air flow going into
the carb resulting in a richer mixture- -this is used the help a cold engine
Trust me - - the choke will not affect the fuel level - I have run motors for years
without the choke hooked up - I always ran the choke fully opened - made for
a need to pump the gas as the motor warmed but then all is fine.

I does sound like the motor is running "lean" and that could be the result of
one of many things. YOu could have debris in the tank or perhaps dirt
clogging the "sock" or pick up in the tank - -BUt I still don't think this is the issue.

If we knew what type of carb - - it would help us tell you what to try next.

BUT for the meantime - - - double check the vacuum lines - -look for cracks
and make sure all the ports on the carb are capped if not in use.

If I knew what type of carb - -I could tell you how to adjust.

It is possible - -you carb is out of adjustment.
Double check the bolts holding the carb to the intake.

My gut felling is you have a vacuum leak. An easy way to check this is to get
a can of carb cleaner and start the motor - -then spray a LITTLE carb cleaner
all around the base of the carb. Then spray a little around the intake.

If the motor rpm increases - -you have a vacuum leak.

My other though is something is blocking the line feeding the fuel pump.

PLease let us know the carb type and size if possible and we will help from there.
You MAY be running out of fuel - -the clear in-line filter is a GOOD idea to have installed and should help us.
Let us know and we will from here

Print Dad

 

[gearheadhick429]

couldn't have said it better myself. good post.
- don't worry about the filter not having gas. if it fills with or without an air bubble while running, it is good. it will seek the same level as the tank so if the clear filter is higher than the tank, it will usually drain depending on the fuel pump stroke.

 

[Driveway]

How old is the coil? When they go bad they may run OK at idle, but crap out under load.

You don't specifically say in the text this is and AT, if yes then you may have an air leak in the modulator line or a bad modulator allowing ATF into the engine. Supporting the vacuum leak idea.

 

[rex1965]

Okay here is my 2 cts. I would run a fuel pump capacity test, this tests the amount of fuel the system can deliver in 20 seconds, thereby testing the sock filter in the fuel tank, the lines, the fuel pump, and your inline filters, the only thing is does not test is the carb. To do the test, disconnect the coil HV wire and ground it so there is no spark and the engine wont' start. Then disconnect the fuel line somewhere near the carb and put a piece of flexible fuel line on the fuel line and put the other end into a metal container at least a quart in size. Place the trans in neutral if manual, and park if auto, then crank the engine for 20 seconds, you should have a least a pint of gas in the can, if it is just under a pint that is probably okay, but if you don't have much in the can, then what I said above needs to be checked. In addition, anytime the fuel system is disturbed, changing a fuel pump, adding or changing a filter, particles get released into the system, which can get into the reed valves in the fuel pump and can affect its efficiency even if it new or the needle and seat in the carb, doing the test will sometimes force enough gas through to clean the reed valves. To have a vacuum leak of the size suggested would most likely be the pcv hose or if power brakes the one way valve on the booster, sometimes when an engine backfires it blows out the plastic plug on the back of the one way valve, we always stuffed a nickle in its place. Post your results. Good Luck.