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By pintoplumber - 5 Years Ago
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I drove the truck up and down about 220 miles crossing the Alleghenies to get to the cabin. I doesn’t want to rev smoothly above 2500 rpm’s or so. Sometimes I hear a blub, blub, blub sound when I’m giving it gas above 2500. I could climb the mountains ok, just keep it below 2500 or so. Today I gave it new points, condenser, and rotor. The old rotor was bent on top, I thought that was going to be it. I pulled all the plugs, they’re all white. The pictures are of 3 and 4. #3 was only hand tight. Am I running too lean? Edelbrock 354 with progressive linkage. I think I have all 3 carbs with .53 jets or possibly .51 jets in the outside carbs. The plugs are at least 2 years old, Autolite 46. The engine is a 239 bored +.125 with a 312 crank. I rpm’s.     
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By charliemccraney - 5 Years Ago
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Does the advance seem to be working? You had an issue with that a couple races ago.
Are the plugs normally that white and has it been driven much since they were installed?
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By paul2748 - 5 Years Ago
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What is the elevation where you are?
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By Hoosier Hurricane - 5 Years Ago
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Dennis:
The plugs look lean to me. Is everything the same since you last raced it? I know it would rpm before. If you haven't messed with the jetting, I would check the fuel supply system from the tank to the carbs. /a big vacuum leak would lean the mixture, but it wouldn't idle worth a darn.
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By Ted - 5 Years Ago
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Hard to tell from the picture but it looks like a lot of ignition timing. I’m basing that on what looks like the color change on the ground strap being close to the base of the spark plug rather than in the curve. Are you sure all three carbs are getting fuel? A stopped up or stuck needle seat on one carb could also be an issue.
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By pintoplumber - 5 Years Ago
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It’s idleing around 450 - 500 right now. I don’t think I’ve got an intake leak. We’re around 2400’ elevation here. There’s a lot of miles on those plugs, I use the truck a lot. It does sit over winter because I don’t run any antifreeze in it. Maybe the outside carbs aren’t giving me fuel. I will recheck the timing, I’m using centrifugal only.
I got to post some pictures from last evening, they’re grainy as it was near dusk. Check out the front door.  
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By RB - 5 Years Ago
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Dennis is that your new Mechanic? LOL
You might drop down to a 45 plug they are a tad colder..Your's look plenty warm and lean Normally with unleaded the porcelain should be tan color rather than white. I agree not wanting to rev over 2500 could be a fuel supply problem
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By pintoplumber - 5 Years Ago
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I’m home again. In the mountains I replaced the points, condenser, and rotor. Initial timing is at 10 degrees. When I rev under no load, it goes up about halfway between the 30 and 40 degree marks. On level ground about 2300 rpm it would sometimes surge. Sometimes under light load, it would backfire out the exhaust. I’m thinking too it’s carburetor problems or maybe fuel pump. My timing marks on the pully are 0 10 20 30 and 40.
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By Hoosier Hurricane - 5 Years Ago
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Dennis:
When you are at 2500 under load, are you getting into your secondary carbs? The reason I ask, I have had experience with older stock Viton needles getting swelled and softened by our wonderful alcohol laced gas. Your secondary carbs probably don't get a lot of use in street driving, so the floats keep pushing the needles into the seats and they don't get a chance to drop out. So when the gas leaves the carbs, the needles don't let more in. Opening the throttle without fuel would amount to a huge infusion of air. This is conjecture on my part, but you have been running this tripower for a lot of years without this issue. Something has changed in your system.
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By RB - 5 Years Ago
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Surging at cruise or under light load is classic lean condition, with backfiring, a lot lean..... Usually you would up the main jets to cure this, but in your case since it has been running in this configuration, something in your fuel delivery has changed or there is a vacuum leak. Conjecture again, maybe one of the 2 main jets is plugged
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By pintoplumber - 5 Years Ago
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I’m thinking the outside carbs are coming in around 2500, judging from my foot pressure on the gas peddle. I took the tops of the 3 carbs off this evening. The front and center carbs had these silver colored valve assemblies. The rear carb has a brass needle valve. I have enough to change the front and center to the brass needle valve. I’m hoping that the front carb wasn’t getting fuel. The photo from above shows the front carb is cleaner. Maybe this has been going on for a while. I poked a straight pin in all 6 jets, they were open. I’ll see if I can get it back together tomorrow night.
  
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By charliemccraney - 5 Years Ago
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The silver ones must be a modern replacement.
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By Joe-JDC - 5 Years Ago
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Make sure you clean out your accelerator pump nozzles tubes in all three carbs. They actually stop up with fuel contaminants quicker than the jets, and they will not give you that shot when the throttle blades first start opening, and that will cause the lean mixture. Joe-JDC
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By pintoplumber - 5 Years Ago
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Well, I got her out tonight for the 1st test drive and it isn’t the float needle. I can shut off the fuel to the outside carbs and loosen the linkage and just run on the center carb and see what it revs like on just the center carb.
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By pintoplumber - 5 Years Ago
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It does the same thing running on just the center carb.
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By charliemccraney - 5 Years Ago
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Maybe a bad fuel pump.
Are the other carbs set up as secondaries? If not, you can swap one of those and see if it is the same.
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By pintoplumber - 5 Years Ago
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pintoplumber (5/26/2019)
It’s idleing around 450 - 500 right now. I don’t think I’ve got an intake leak. We’re around 2400’ elevation here. There’s a lot of miles on those plugs, I use the truck a lot. It does sit over winter because I don’t run any antifreeze in it. Maybe the outside carbs aren’t giving me fuel. I will recheck the timing, I’m using centrifugal only. I got to post some pictures from last evening, they’re grainy as it was near dusk. Check out the front door.
We're at the cabin this weekend. A couple of minutes ago, the 3 legged bear was here. The front door wasn't shut tight, and he pushed the screen in and the door opened, we all screamed. I believe we scared him as much as he scared us.
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By pegleg - 5 Years Ago
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The mighty white hunters!! Yeah I would have screamed too!
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By pintoplumber - 5 Years Ago
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Well, I’ve got an update. The last thing we decided out at Harry’s was to change the plug wires. I ordered some new ones from Mac’s. Got them on this weekend. When I looked at the old ones, one on the drivers side was missing the metal thingy that fits on the spark plug. I drove 130 miles yesterday to an AMC show and it ran great.
 
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By pegleg - 5 Years Ago
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So I managed to beat a 7 cylinder 239 in a truck with a 2 bbl? Uh...………….Ok!!
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By 57FordPU - 5 Years Ago
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Now, that's funny right there. (Larry the Cable Guy quote)
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By pintoplumber - 5 Years Ago
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Happy belated birthday Charlie
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By pintoplumber - 5 Years Ago
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Coming back from a car show,about a mile from home at a stop sign, it stayed in 3rd gear. Can’t move the shift lever. Guess I have to drop it today. 3 speed w/overdrive column shift.
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By pintoplumber - 5 Years Ago
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Turns out it was a problem with the side cover. Took it apart and stretched the spring, seems like it’s working again.   
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By pintoplumber - 5 Years Ago
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Turns out it was my input shaft bearing. Nearly all back together.     
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By pintoplumber - 5 Years Ago
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All back together again, ready to reinstall in the truck. 
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By KULTULZ - 5 Years Ago
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Has this condition been analyzed/corrected?
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By pintoplumber - 5 Years Ago
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Yes, that would have been caused by my not getting the distributor cap on correctly. My big problem was the spark plug wire not having the metal end in it.
As for the transmission locking up in 3rd, I was only a mile from home. The previous weekend I drove 617 miles up to the mountains and back. Glad it didn’t happen up there.
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