1981 straight six manual 4x4 project

[Ford F834]

Running a quart of transmission fluid mixed with your oil will clean the lifters. I woulds drive it about 50 miles, then drain.

I actually thought about doing that before I drained it this time, but he I'm a little chicken to do it right before a long trip after what happened to David. I didn't want to break a bunch of crap loose and clog the screen. If it keeps it up I might do it when I get back and can drive it around close to home.

[Gary Lewis]

Running a quart of transmission fluid mixed with your oil will clean the lifters. I woulds drive it about 50 miles, then drain.

I actually thought about doing that before I drained it this time, but he I'm a little chicken to do it right before a long trip after what happened to David. I didn't want to break a bunch of crap loose and clog the screen. If it keeps it up I might do it when I get back and can drive it around close to home.

On the heater, pull the blower motor and look in there. That's where lots of stuff goes, and the mice can get to it if the blend door is open/broken. Plus, it is easy to get to in order to clean out.

As for the oil, I agree about not doing the clean-out on a long trip. But 45 psi at idle is a lot. So, it looks like the engine is in good shape, although you don't know about how dirty things are. Best to play it safe.

And I like the wheels and tires. Big Blue's are wide enough that they can't really sit in like yours w/o rubbing on many turns, but yours fit nicely. And those E's should be good for where you are going.

[1986F150Six]

"I checked the speedometer ~before the bigger wheels and I was only 2-3 mph slow, and 1 mile on the odometer was 1.1 actual miles. This will obviously be worse with the bigger wheels, but still useable for the time being".

Based on your posted numbers, the odometer is off [low] by 10%. The gas mileage will be low by 10% as well.

"The truck still runs rich and stinky. I have not filled the tank yet, but it's looking like my mpg may be really terrible. I'm actually thinking of stealing the carburetor off of the 1968 to see if it changes. I tried leaning out the carb that is on it and it didn't like that very much".

My initial 2 tanks returned 11 and 9 mpg. Perhaps your sending unit is whacko and drops in a very nonlinear fashion. What vacuum does the engine pull @ idle? Have you tried advancing the timing? Have you felt the hubs after driving to make sure the brakes are not dragging?

 

[Ford F834]

"I checked the speedometer ~before the bigger wheels and I was only 2-3 mph slow, and 1 mile on the odometer was 1.1 actual miles. This will obviously be worse with the bigger wheels, but still useable for the time being".

Based on your posted numbers, the odometer is off [low] by 10%. The gas mileage will be low by 10% as well.

"The truck still runs rich and stinky. I have not filled the tank yet, but it's looking like my mpg may be really terrible. I'm actually thinking of stealing the carburetor off of the 1968 to see if it changes. I tried leaning out the carb that is on it and it didn't like that very much".

My initial 2 tanks returned 11 and 9 mpg. Perhaps your sending unit is whacko and drops in a very nonlinear fashion. What vacuum does the engine pull @ idle? Have you tried advancing the timing? Have you felt the hubs after driving to make sure the brakes are not dragging?

David,

I will report an approximate mpg when I fill the tank. Right now there are a lot of unknowns. The sending unit is new, but it does float around a bit and seemed to be reading low when I initially filled the tank.

I don't happen to have a vacuum gauge, so I don't know what it is pulling at idle. I'm drawing the distributor advance from a port on the passenger side of the carburetor base.

I need to time it again with the timing light. After I deleted the vacuum booster it ran like crap. I reset the timing by ear, but it would bog and almost die when I would goose the throttle, so I backed off on it until I got decent response throughout. That's where it still sits, but I don't know where that is in degrees...

I really feel like this carburetor may have problems. Sometimes it runs extremely smooth, other times it stutters and stumbles quite a bit, and it is way harder to start than it should be (unless hot, then it fires at the touch of the key). I know the carb on my 1968 isn't perfect (just a junkyard take-off) but that truck has run pretty well for me so I may swap it on and see if anything changes.

 

[Gary Lewis]

David,

I will report an approximate mpg when I fill the tank. Right now there are a lot of unknowns. The sending unit is new, but it does float around a bit and seemed to be reading low when I initially filled the tank.

I don't happen to have a vacuum gauge, so I don't know what it is pulling at idle. I'm drawing the distributor advance from a port on the passenger side of the carburetor base.

I need to time it again with the timing light. After I deleted the vacuum booster it ran like crap. I reset the timing by ear, but it would bog and almost die when I would goose the throttle, so I backed off on it until I got decent response throughout. That's where it still sits, but I don't know where that is in degrees...

I really feel like this carburetor may have problems. Sometimes it runs extremely smooth, other times it stutters and stumbles quite a bit, and it is way harder to start than it should be (unless hot, then it fires at the touch of the key). I know the carb on my 1968 isn't perfect (just a junkyard take-off) but that truck has run pretty well for me so I may swap it on and see if anything changes.

I think I'd swap the carbs if you know the other one is good. Can't hurt.

[Ford F834]

David,

I will report an approximate mpg when I fill the tank. Right now there are a lot of unknowns. The sending unit is new, but it does float around a bit and seemed to be reading low when I initially filled the tank.

I don't happen to have a vacuum gauge, so I don't know what it is pulling at idle. I'm drawing the distributor advance from a port on the passenger side of the carburetor base.

I need to time it again with the timing light. After I deleted the vacuum booster it ran like crap. I reset the timing by ear, but it would bog and almost die when I would goose the throttle, so I backed off on it until I got decent response throughout. That's where it still sits, but I don't know where that is in degrees...

I really feel like this carburetor may have problems. Sometimes it runs extremely smooth, other times it stutters and stumbles quite a bit, and it is way harder to start than it should be (unless hot, then it fires at the touch of the key). I know the carb on my 1968 isn't perfect (just a junkyard take-off) but that truck has run pretty well for me so I may swap it on and see if anything changes.

I filled the tank today and using the odometer correction factor that I got from the GPS it looks like I ran 12.5 mpg. That's not as horrible as I feared but nowhere near where I want it either. Granted most of that was short trips, start stop driving and a lot of warm up idling, so I'm not discouraged. We will see what it does with the other carb and timing with the light.

I've been driving it around while preparing for our road trip and the more I drive it the more I like the gearing. The start out gear is just fine, I just have to slip the clutch a bit more than I'm used to on my other trucks. The closer ratios of the diesel T-19 are just what the doctor ordered for the straight six. I thought the taller tires would make it worse, but if anything they handle better. I just love this whole set up.

While cleaning and moving furniture in our camper I managed to break the large front window... doh! Even with six glass shops right in town no one could cut a piece of SS on short notice... really? I had to beg one guy to do it for me this morning (Saturday) so that I can get this show on the road! Luckily I have some flexibility in my vacation schedule so we still have plenty of time.

[Gary Lewis]

I filled the tank today and using the odometer correction factor that I got from the GPS it looks like I ran 12.5 mpg. That's not as horrible as I feared but nowhere near where I want it either. Granted most of that was short trips, start stop driving and a lot of warm up idling, so I'm not discouraged. We will see what it does with the other carb and timing with the light.

I've been driving it around while preparing for our road trip and the more I drive it the more I like the gearing. The start out gear is just fine, I just have to slip the clutch a bit more than I'm used to on my other trucks. The closer ratios of the diesel T-19 are just what the doctor ordered for the straight six. I thought the taller tires would make it worse, but if anything they handle better. I just love this whole set up.

While cleaning and moving furniture in our camper I managed to break the large front window... doh! Even with six glass shops right in town no one could cut a piece of SS on short notice... really? I had to beg one guy to do it for me this morning (Saturday) so that I can get this show on the road! Luckily I have some flexibility in my vacation schedule so we still have plenty of time.

Glad you got the window fixed. Bummer!

But, 12.5 MPG on gas that may have been sitting around and in start/stop driving isn't terrible. And the other carb may help it.

As for the gearing, glad it is working. However, do you think you'll need to change the diff's? Or will starting in 4lo with the trailer do it for you?

[Ford F834]

As for the gearing, glad it is working. However, do you think you'll need to change the diff's? Or will starting in 4lo with the trailer do it for you?

I think 4Lo starts for towing will work for me... but I will report back after I actually tow with it that way. I can either get it rolling in 1st Lo and jump to 1st Hi, or I can shift 1-4 Lo then jump to 2 Hi for a nice close 7-speed gear set. I'll be shifting like a semi driver but I won't have to rev much past the torque peak... ever.

I don't really want to change diffs if possible, as that will hurt the overdrive end of things and I'm liking where the shift points fall as-is. I'd have to go down to at least 4.10's to make 1st a stout towing gear.

If this set up does not do it for me then I might consider a ZF-5 and give up the close ratios... but the long term plan is to tow with the diesel, not the straight six. As long as it's manageable I will probably leave it alone, or *maybe add an overdrive if I feel it crying for one. I can't say this enough... i ~really like the way the truck drives and handles just the way it is. It has exceeded my expectations and the 4Lo starts are just for towing heavy. 1st gear final ratio is 12.06:1 so I just need the TC Lo range to save the clutch and avoid lugging. I'm used to 12.63:1 2nd gear starts in my 4.10 trucks with T-18's, and only rarely needed 1st/Lo. This truck drives around town beautifully and the tach reads 1,000-1,200 most of the time 🙂

[PetesPonies]

As for the gearing, glad it is working. However, do you think you'll need to change the diff's? Or will starting in 4lo with the trailer do it for you?

I think 4Lo starts for towing will work for me... but I will report back after I actually tow with it that way. I can either get it rolling in 1st Lo and jump to 1st Hi, or I can shift 1-4 Lo then jump to 2 Hi for a nice close 7-speed gear set. I'll be shifting like a semi driver but I won't have to rev much past the torque peak... ever.

I don't really want to change diffs if possible, as that will hurt the overdrive end of things and I'm liking where the shift points fall as-is. I'd have to go down to at least 4.10's to make 1st a stout towing gear.

If this set up does not do it for me then I might consider a ZF-5 and give up the close ratios... but the long term plan is to tow with the diesel, not the straight six. As long as it's manageable I will probably leave it alone, or *maybe add an overdrive if I feel it crying for one. I can't say this enough... i ~really like the way the truck drives and handles just the way it is. It has exceeded my expectations and the 4Lo starts are just for towing heavy. 1st gear final ratio is 12.06:1 so I just need the TC Lo range to save the clutch and avoid lugging. I'm used to 12.63:1 2nd gear starts in my 4.10 trucks with T-18's, and only rarely needed 1st/Lo. This truck drives around town beautifully and the tach reads 1,000-1,200 most of the time 🙂

The YF, if that is what you have . . has a design element I don't like. The accelerator pump is such that if the diaphragm rips( and they all do eventually) not only does the acceleration circuit not work, but now the carb will be overly rich. This is because fuel will actually drip into the venturi area from a rip in the diaphragm. If you ever have a rich problem, it's something to check for sure.

[Gary Lewis]

The YF, if that is what you have . . has a design element I don't like. The accelerator pump is such that if the diaphragm rips( and they all do eventually) not only does the acceleration circuit not work, but now the carb will be overly rich. This is because fuel will actually drip into the venturi area from a rip in the diaphragm. If you ever have a rich problem, it's something to check for sure.

Jonathan - You have a plan and I'll bet it'll work. When you get the diesel going you won't need to start in low range, so don't gear for towing.

Pete - The old leather skirts on the accelerator pump pistons do tend to crack. Even the synthetic one on Big Blue's Eddy was bad when I got it. So, that is a good place to look.