I'm finally starting to drive the truck to more than just the water station a 1/4 mile down the road... And I'm discovering that it's often annoying to drive.

If the truck hasn't heated up to where the thermostat has opened, it bogs BAD and will often backfire into the carb. I also have noticed that when I shut it off that air bubbles will form in the fuel filter. More than once the filter has been drained totally. Even with reset timing, the truck detonates once on start just about every time.

Today was more interesting than most because I woke up late for work and had to gtfo in a hurry. So the truck only had enough time to be running for about 3 mins. Once I get to the road, I go to take off and bogs almost dieing. Wasn't on the throttle much at all but enough to normally take off with some vigor. Backfires into the carb several times and then goes once I get back out of it and finally goes somewhat. And all the way to the guy that I ride to work with's house, it's backfiring and all kinds of bogging. Even when I needed just a little more power because the *** end let go in a corner, I tried pedaling it through but it just lost power and then backfired into the carb and the truck caught throwing me and everything everywhere.

On the way home today, I let it warm up for about 10 mins and still same crap only this time it was dropping cylinders like when I've had cars lose crank sensors and only fire every other cylinder. Did this until it got some heat in the engine. Seemed to run a little better after I turned it off after chasing some cows on the road but still would bog. I'm really getting annoyed with it.

Information on the truck: 1979 F-250, 351M, 4 speed, headers, edelbrock intake and new(still have the box) 1406 carb, questionable rebuild on engine, timing at 12 degrees, 180 t-stat, 33x12.50x16.5 tires, 3.54 gears, no bed, new looking dizzy, new fuel lines and new fuel tank with new looking fuel pump.

I have another blue box that I can plug in to see if that will work and I think I have another dizzy around that is supposed to be good without getting the one out of the extra engine. Worst comes to worst, I also have a 6AL box I can install. I haven't driven a carbed vehicle in a long time so my tuning skills are rusty and I need help here.

 

id check plugs, and plug wires along with making sure there in the right order! If not that maybe carb us way out of whack!

 

I think it's a combination of both ignition and fuel. Hang on now before ya go throwing a bunch of parts at it. Go back to the basics like plug wires and firing order, vacuum hoses, electrical connections, etc.

It could be as easy as the dizzy hooked up to the wrong vacuum port.. IIRC, the 1406 has like two on the front and one on the passenger side....

 

I've played the parts throwing game on other cars. Not doing that again. Plug wires are in good shape visually and are in the right order. It's been a long time since I did anything V8 related but the diagrams I saw for ford seemed right where #1-4 are on the pass side and #5-8 are on the drivers side. It is in the correct 1-3-7-2-6-5-4-8 pattern. I'll have to check the book and look at the vac advance port on the carb tomorrow. And I will make sure that the dizzy is advancing if it's not raining. As for vacuum hoses, there aren't many on the engine at ALL. I really need to find my book so that I can get those straight. Though the truck has manual heater controls, there seems to be a vac leak in the cab somewhere.

Also, would not having the factory temp gauge hooked up cause the electric choke to become engaged after more than half throttle? I can do this and it will get stuck on and I have to take it off high idle again.

 

Sounds like a fuel delivery and/or timing issue.

 

Finally got some time with the truck today. Took the cap off to check the vac advance. It moves smoothly though it seems like it has a hell of a spring. It also looks to be a reman dist. Noticed that I could twist the distributor enough that it would likely fire the next plug ahead of it. It's kind of springy. But would this be possibly a dist gear or cam going bad? Been driving the truck to work and though it's hot in the afternoons it runs good. But will still backfire into the carb just randomly going down the road.

 

You say "I could twist the distributor enough that it would likely fire the next plug ahead of it. It's kind of springy." I assume you mean you could turn the shaft that much, by just turning the rotor? You couldn't turn the body of the dizzy as it is held fiorm to the block with the hold-down clamp... Right? There's almost always a tiny bit of play in the shaft, from a bit of clearance on the drive gear, but the kind of play you describe doesn't seem right. The engine can't fire properly with that . Have you lifted that shaft out to check it?

 

Pulled the dist. and at a glance it looks like the cam is eating the dist gear. But when I re-timed it, I checked to see how smooth it was up until full advance. Advance is smooth in operation and the timing doesn't jump around. Maybe with setting it again to what the hood says of 4* BTDC will make it run better. Though it seems that it ran better straight up at 0*. Didn't take it for a drive at either setting because it's crazy low on fuel. Have some pics that I will edit in when I get them off the card.

 

It sounds to me like there is something up with that dizzy gear, and if so the timing marks won't tell you much.

 

Here's the pics.

Dist at rest
http://i86.photobucket.com/albums/k1...t/DSCF9083.jpg

Dist at max play
http://i86.photobucket.com/albums/k1...t/DSCF9084.jpg

Dist gear
http://i86.photobucket.com/albums/k1...t/DSCF9085.jpg

Cam Gear. Really hard to get a pic of.
http://i86.photobucket.com/albums/k1...t/DSCF9087.jpg

Dist cavity.
http://i86.photobucket.com/albums/k1...t/DSCF9088.jpg

 

Looks like a lot of play. Here's a thought: you said earlier this engibne had a "questionable rebuild". I wonder if your problem is related to a misalignment of the timing chain/gears, perhaps associated with that. If your cam and crank gears are not positioned corrected with respect to each other when the chain is installed, the timing will always be off regardless what the timing light says (and in fact will certainly be off when the light says its correct). This might also be contributing to your dizzy gear and the drive gear meshing wrong and chewing up. Have you tried ignoring the timing light and just going by ear and smoothness?

 

It ran night and day different this morning and afternoon. Going to try setting it to 0 because that is where it sounded and felt best but we shall see with the detonation. When a "straight up" timing set is installed, are you still supposed to time it at 4* BTDC or at 0* since the cam is now lacking it's inherent 4* retard?

 

Sorry friend, I can't help with that question. But I'm sure someone on here could. If I could make a suggestion, perhaps you should re-post your question with a new, more specific subject.