1981 straight six manual 4x4 project

[Ford F834]

So if you have a clogged pickup screen... you are supposed to blow all that crap back into the tank along with a dislodged ‘sock’? after my experience with the plastic bag fragment I think I would take the time to drop the tank and remove the screen manually, or replace it with a new clean screen... but it must work out if that was a standard practice.

David, if you are willing to part with your old distributor I may be interested in it if you will let me pay a fair used price for it. I don’t know how much you have invested in it with the recurve etc., but we can talk about it via email. The one question I have is it DSII or does it have its own module? I will probably have to do something in the interim (maybe change the pick up as Gary suggested) since I must haul water.

Update... after messing with the distributor I drove ~150 local miles with zero stalling problems. As I said before, I didn’t actually change anything, so the problem would no doubt return at some point. Since the distributor was the last thing to be messed with, I am confident that this is where the problem is.

David mailed me his performance distributor on Monday and it arrived today (Wednesday)

When it started to cool off this evening I installed it and set it at 17* BTDC per David’s suggestion since that is where it performed best on his truck. I could tell right away that the truck sounded the best by ear with lots of advance.

I took it for a spin (water haul run) and found that the advance was too much. It would ping pretty bad when I put my foot down even unloaded on flat ground. So after I filled the water tank, I pulled to the side and backed off the timing to 16* maybe 15.5* (eyeballing where there are no marks). The ping disappeared. Even on a slight incline with 2,200 lb load I could mash my foot to the floor and no pinging at all.

Other observations... the engine has always run pretty well, but this is by far the best it has ever been. It has a nice smooth idle, the nagging hesitation when you stab the throttle is gone. If you punch it while driving it will actually lurch the driveline which it never did before. The responsiveness is very noticeable. I can’t really tell how it pulls compared to before, since my water route is fairly flat, but it seems strong through the rpm band and at least ~sounds better in the higher revs.

This is always a funky comparison, to talk about a performance part compared to a bad/failing stock counterpart. All I know is there is a very noticeable improvement with the new distributor beyond just ~not stalling. I am very happy, and would like to send a very special thanks to David/1986F150six for sending the part to me. I have been nervous to drive the truck very far, and I need to bring a load of tools, wood etc., to our new place (which I can now do). I will keep track of the mpg to see if it changes with the different timing curve.

 

[Gary Lewis]

Update... after messing with the distributor I drove ~150 local miles with zero stalling problems. As I said before, I didn’t actually change anything, so the problem would no doubt return at some point. Since the distributor was the last thing to be messed with, I am confident that this is where the problem is.

David mailed me his performance distributor on Monday and it arrived today (Wednesday)

When it started to cool off this evening I installed it and set it at 17* BTDC per David’s suggestion since that is where it performed best on his truck. I could tell right away that the truck sounded the best by ear with lots of advance.

I took it for a spin (water haul run) and found that the advance was too much. It would ping pretty bad when I put my foot down even unloaded on flat ground. So after I filled the water tank, I pulled to the side and backed off the timing to 16* maybe 15.5* (eyeballing where there are no marks). The ping disappeared. Even on a slight incline with 2,200 lb load I could mash my foot to the floor and no pinging at all.

Other observations... the engine has always run pretty well, but this is by far the best it has ever been. It has a nice smooth idle, the nagging hesitation when you stab the throttle is gone. If you punch it while driving it will actually lurch the driveline which it never did before. The responsiveness is very noticeable. I can’t really tell how it pulls compared to before, since my water route is fairly flat, but it seems strong through the rpm band and at least ~sounds better in the higher revs.

This is always a funky comparison, to talk about a performance part compared to a bad/failing stock counterpart. All I know is there is a very noticeable improvement with the new distributor beyond just ~not stalling. I am very happy, and would like to send a very special thanks to David/1986F150six for sending the part to me. I have been nervous to drive the truck very far, and I need to bring a load of tools, wood etc., to our new place (which I can now do). I will keep track of the mpg to see if it changes with the different timing curve.

Congrat's!!! Not only is the problem probably gone, but the smoothness, performance, and surely the MPG have been increased. In one fell swoop. And, now you'll feel more comfortable not just hauling water or lumber and tools, but driving long distances.

As for David, that's just the kind of guy he is.

[1986F150Six]

Congrat's!!! Not only is the problem probably gone, but the smoothness, performance, and surely the MPG have been increased. In one fell swoop. And, now you'll feel more comfortable not just hauling water or lumber and tools, but driving long distances.

As for David, that's just the kind of guy he is.

Thanks to both of you.

Jonathan, I just remembered that the vacuum canister has been maxed out in that it was adjusted to where I could just have a hint of pre-ignition with moderate load at partial throttle. Gary can better explain, but after it was adjusted while at the Garagemahal, I continued to make further adjustments with each fill-up. You might be able to back off what I had done and then further advance the static.

I am very happy regarding the performance enhancement for your truck! Thanks for the feedback.

[Ford F834]

Thanks to both of you.

Jonathan, I just remembered that the vacuum canister has been maxed out in that it was adjusted to where I could just have a hint of pre-ignition with moderate load at partial throttle. Gary can better explain, but after it was adjusted while at the Garagemahal, I continued to make further adjustments with each fill-up. You might be able to back off what I had done and then further advance the static.

I am very happy regarding the performance enhancement for your truck! Thanks for the feedback.

Thanks for the info David, I have a bit to learn about the tuning. So far I have just been happy to have it running.

You are also running manifold vacuum correct? I left my line on the Venturi port, but perhaps it will now tolerate more at idle?

Forgive me, I know you told me before, but how did you extend the timing marks to set it beyond what is cast into the timing cover? I was just eyeballing it, but that is a fairly difficult spot to read, especially since the AC compressor sits where you need to have the timing gun. I am starting to see why people remove it if they are not using it.... but this has been a harsh summer and mine goes nowhere 😬

(Photo of the dash in my wife’s car as we drove around Bullhead City... finishing the AC in the ‘81 is on the short list!)

[1986F150Six]

Thanks for the info David, I have a bit to learn about the tuning. So far I have just been happy to have it running.

You are also running manifold vacuum correct? I left my line on the Venturi port, but perhaps it will now tolerate more at idle?

Forgive me, I know you told me before, but how did you extend the timing marks to set it beyond what is cast into the timing cover? I was just eyeballing it, but that is a fairly difficult spot to read, especially since the AC compressor sits where you need to have the timing gun. I am starting to see why people remove it if they are not using it.... but this has been a harsh summer and mine goes nowhere 😬

(Photo of the dash in my wife’s car as we drove around Bullhead City... finishing the AC in the ‘81 is on the short list!)

Yes, mine is connected to manifold vacuum.

The timing marks on mine are not difficult to see. They are on the passenger side.

 

[Ford F834]

Yes, mine is connected to manifold vacuum.

The timing marks on mine are not difficult to see. They are on the passenger side.

Thank you David, perhaps mine is missing a scale then. My damper has two notches in it, but I have been using the marks on the gear cover...

[1986F150Six]

Thank you David, perhaps mine is missing a scale then. My damper has two notches in it, but I have been using the marks on the gear cover...

Jonathan,

I went back over notes and I was mistaken [sorry] when I said 17* BTDC. It should have been 14*. At one time, I did have it @ 17*, but had the vacuum advance blocked off.

David

[Gary Lewis]

Thanks for the info David, I have a bit to learn about the tuning. So far I have just been happy to have it running.

You are also running manifold vacuum correct? I left my line on the Venturi port, but perhaps it will now tolerate more at idle?

Forgive me, I know you told me before, but how did you extend the timing marks to set it beyond what is cast into the timing cover? I was just eyeballing it, but that is a fairly difficult spot to read, especially since the AC compressor sits where you need to have the timing gun. I am starting to see why people remove it if they are not using it.... but this has been a harsh summer and mine goes nowhere 😬

(Photo of the dash in my wife’s car as we drove around Bullhead City... finishing the AC in the ‘81 is on the short list!)

Jonathan - The port on the carb only goes to something like 11" of vacuum, assuming your carb is like David's. And 11" isn't enough to pull the vacuum advance on fully, at least the way I think that one is set up.

So, I'd go to manifold vacuum ASAP. But, then you'll have more advance when cruising, so listen for pinging under part throttle. And if you have pinging then back off the vacuum advance by turning an allen wrench counter-clockwise (I think) a turn at a time until the pinging stops.

But I wouldn't play with the initial advance to quell the pinging if the engine is starting well with that timing. Too much initial causes the engine to kick back during starting, but if yours is happy where you have it then I'd leave it and work on the vacuum advance.

A simplistic, but not completely accurate, way of looking at the order of tuning is:

1: Initial advance. Dial in enough to get the engine to idle well but not enough to kick back in starting.

2: Centrifugal: In your case that's a given as David had that dizzy set up for his truck and that's a fairly close match to yours. But, what about EGR? There's a huge difference in the advance curve for with and without EGR, so what do you have? And, David, was the dizzy set up for EGR?

3: Vacuum: Dial in all the vacuum you can use w/o pinging at part throttle. Typically the most critical spot is your top gear at low RPM, but check it out to ensure you aren't pinging anywhere.

[1986F150Six]

Jonathan - The port on the carb only goes to something like 11" of vacuum, assuming your carb is like David's. And 11" isn't enough to pull the vacuum advance on fully, at least the way I think that one is set up.

So, I'd go to manifold vacuum ASAP. But, then you'll have more advance when cruising, so listen for pinging under part throttle. And if you have pinging then back off the vacuum advance by turning an allen wrench counter-clockwise (I think) a turn at a time until the pinging stops.

But I wouldn't play with the initial advance to quell the pinging if the engine is starting well with that timing. Too much initial causes the engine to kick back during starting, but if yours is happy where you have it then I'd leave it and work on the vacuum advance.

A simplistic, but not completely accurate, way of looking at the order of tuning is:

1: Initial advance. Dial in enough to get the engine to idle well but not enough to kick back in starting.

2: Centrifugal: In your case that's a given as David had that dizzy set up for his truck and that's a fairly close match to yours. But, what about EGR? There's a huge difference in the advance curve for with and without EGR, so what do you have? And, David, was the dizzy set up for EGR?

3: Vacuum: Dial in all the vacuum you can use w/o pinging at part throttle. Typically the most critical spot is your top gear at low RPM, but check it out to ensure you aren't pinging anywhere.

The distributor was set for no EGR.

[Gary Lewis]

The distributor was set for no EGR.

Perfect! Exhaust gas in the air/fuel mix makes the flame front slow to spread, so the timing has to be advanced a long ways. But, since they only introduce exhaust gas during high-vacuum situations, like cruising, then they can't dial the extra lead into the centrifugal curve. So it goes into the vacuum advance curve.

However, if you run a dizzy set up for EGR w/o EGR on the engine, like Big Blue's probably is, you'll have pinging galore under light throttle. Which explains why I have to pull the vacuum line off the dizzy when towing - until I really give it heavy throttle there's too much vacuum advance and it'll do worse than ping.