If it's not one thing..

phat46 · July 12, 2010, 04:11:17 PM

I thought I had my '46 truck sorted out but no such luck. I had problems before with it stalling. I could make it run o.k. if i turned the idle way up. After checking everything I could think of and the things I learned on this forum I took the carb apart and cleaned it. That seemed to make all the difference. Last weekend we had the annual "Classic Car Weekend" here in town. I took the truck on the parade cruise and it was fine for the first five or so miles then it started stalling and running rough, like it had a couple fouled plugs. I limped it home and the next day i took the plugs out. None we reall bad but a couple were pretty black. Cleaned the plugs and started it up; it seemed to run good but after only two blocks it was right back to the way it was. Pulled the plugs and they looked good. I'm thinking the carb is gummed up again. A friend told me a story about revving the engine up high and quickly covering the carb with a large rag. Supposedly this will pull crap through the carb and clean it out. Don't know if I want to try that... What are peoples thoughts on Edelbrock carbs? Maybe I should see if I can borrow a different carb and see what happens. Any ideas?

edit, it's on a 1970 429 Ford engine.

GPster · July 12, 2010, 04:31:04 PM

This is an "Off the Wall" suggestion. Did you clean the gas tank and use sealer in it when you built it? I did that one time and it evidently never set up properly. It made it through the tank strainer, through the fuel pump. through the filter and then started to congeal in the float bowl of the carb. It looked like silicone. What did you clean out of the carb GPster

phat46 · July 12, 2010, 04:36:17 PM

Quote from: "GPster"This is an "Off the Wall" suggestion. Did you clean the gas tank and use sealer in it when you built it? I did that one time and it evidently never set up properly. It made it through the tank strainer, through the fuel pump. through the filter and then started to congeal in the float bowl of the carb. It looked like silicone. What did you clean out of the carb GPster

Yes Joe I made the tank and sealed it. That was about five years ago. When I cleaned the carb it had very little stuff in it, just sediment, no sealer. I'll have to take the carb a part a have a look. I had the same thought as you about the sealer.

32coupe · July 12, 2010, 06:55:07 PM

Do you have an inline gas filter?

If so get a new one

enjenjo · July 12, 2010, 07:25:00 PM

Yake the fuel cap off and see if it's a venting problem.

phat46 · July 12, 2010, 08:15:49 PM

Quote from: "32coupe"Do you have an inline gas filter?

If so get a new one

Yup, got that scheduled too, although the present filter has only a few hours on it.

phat46 · July 12, 2010, 08:20:59 PM

Quote from: "enjenjo"Yake the fuel cap off and see if it's a venting problem.

I don't think it's a venting problem...it's at idle and just off idle where it's the worse. At w.ot. it's not a problem..I was p*$$ed at it and punched it from a dead stop so now there 150' black stripe the next block over. :oops: It seems like it's in the idle curcuit.

chimp koose · July 13, 2010, 04:19:10 AM

dirt in the air bleeds on the idle circuit?

UGLY OLDS · July 13, 2010, 09:46:05 AM

What he said ^^^^^^^^^^^^ ... Try removing the mixture adjusting screws & shoot some carb cleaner in the holes ..Also ..Shoot some in the air bleeds under the choke plate ....

The "RPM & Rag" thing is best left for "Old Cars with Old Carbs" ....It usually does more harm than good .....

Bob.....

HotRodLadyCrusr · July 13, 2010, 08:12:54 PM

Two things, perhaps you need different metering rods (sp?) for the carb. I remember many years ago when I first got Big Olds my brand new Elderbrock card didn't seem to be preforming properly. Those little tiny rods were changed out and that solved the problem.

And/or when I first got Big Olds and was cruzn around the fairgrounds low and slow, after awhile the fuel got hot and Big Odls would stumble and die sometimes. I put one of those 1 inch plastic spacers under the carb and it took care of the vapor lock/dying issue.

1970 Olds 455

53stvblt · July 14, 2010, 08:58:18 AM

I don't think it's a venting problem...it's at idle and just off idle where it's the worse. At w.ot. it's not a problem.

It's easy to determine if the 2 air/fuel idle adjusting circuit is faulty by simply adusting the screws by a coupla turns or so either in or out while listening for the engine RPM to drop.
If theres no drop in RPM that circuit is clogged. Remove the idle screw & use an air gun (I set mine at 40psi) & give it a quick blast of air. Reinstall the adj screw & run it into where it just seats then back out about 1-1/2 to 2 turns. Start the engine & then fine tune to your liking, either centered between the RPM drop points or a bit rich (out) or a bit lean (in).
I like my Edelbrock just fine.
Just FYI, Bud

phat46 · July 14, 2010, 12:35:44 PM

Quote from: "HotRodLadyCrusr"Two things, perhaps you need different metering rods (sp?) for the carb. I remember many years ago when I first got Big Olds my brand new Elderbrock card didn't seem to be preforming properly. Those little tiny rods were changed out and that solved the problem.

And/or when I first got Big Olds and was cruzn around the fairgrounds low and slow, after awhile the fuel got hot and Big Odls would stumble and die sometimes. I put one of those 1 inch plastic spacers under the carb and it took care of the vapor lock/dying issue.

1970 Olds 455

Denise, before this started it ran great, it was a sudden thing. Now it does it right after I get it started, way before it could get hot enough to make a spacer neccessary.

phat46 · July 14, 2010, 12:39:44 PM

Quote from: "53stvblt"I don't think it's a venting problem...it's at idle and just off idle where it's the worse. At w.ot. it's not a problem.

It's easy to determine if the 2 air/fuel idle adjusting circuit is faulty by simply adusting the screws by a coupla turns or so either in or out while listening for the engine RPM to drop.
If theres no drop in RPM that circuit is clogged. Remove the idle screw & use an air gun (I set mine at 40psi) & give it a quick blast of air. Reinstall the adj screw & run it into where it just seats then back out about 1-1/2 to 2 turns. Start the engine & then fine tune to your liking, either centered between the RPM drop points or a bit rich (out) or a bit lean (in).
I like my Edelbrock just fine.
Just FYI, Bud

Yeah I think pretty much it's an idle curcuit problem. I know before I took the carb apart and cleaned it the idle screws mad no difference where I put them, even taking them out! I'll try the airline idea, that's what they guy that told me about revving it and stuffing a rag in the carb was thinking, it would pull the crap out of the curcuits.

Mikej · July 14, 2010, 01:21:40 PM

If your throttle plates are open to far the idle screws won't make any difference either.

phat46 · August 07, 2010, 11:53:04 AM

I finally got time to look at my truck. I was going to fix it today no matter what it took. I started with the simplist thing, a rag over the carb while revving the engine. That did the trick! I did it three times to be sure, but after the first time it smoothed out and is idling nicely. I'll have to remember this in the future.