1984 Bronco build thread

[Ford F834]

Thanks Gary! Your site, the awesome members on it, and the collection of technical resources that it offers are the only reason that the Bronco is running right now. So thank you!

Now on to the rest.

I realize the party is over and everyone has gone home, but I am attaching a couple photos that might help someone else. These are the plugs on my ‘81 straight six that is DSII from the factory, with tach option. I am also including the images I saved and used to convert the breaker points ignition on my old 240 straight six to duraspark. Nothing new or different than what has already been discussed here, just more images that might click with someone...

[1986F150Six]

I realize the party is over and everyone has gone home, but I am attaching a couple photos that might help someone else. These are the plugs on my ‘81 straight six that is DSII from the factory, with tach option. I am also including the images I saved and used to convert the breaker points ignition on my old 240 straight six to duraspark. Nothing new or different than what has already been discussed here, just more images that might click with someone...

That is good, Jonathan!

[StraightSix]

That is good, Jonathan!

FordF843 and Jim,

Thanks for contributing pictures of your vehicles to the thread. Hopefully all of this will help someone else do their Duraspark 2 upgrade. Its alarming how many posts on the duraspark upgrade have been written but don’t seem to have their pictures intact. Here is a picture of mine after completing the upgrade –

The bottom plug (that Im holding in the picture) has 4 conductors coming from the cab. In my original TFI harness, the 4rth conductor went to a blank plug and thus didn't do anything. The other 3 wires are bat + to the coil, the water temp sender, and the oil pressure sender. This is one of the ones that gave me fits, because my donor harness didn't have this plug, it had that bizarre gray square plug. I cut the “engine side” of that connector out of my TFI harness and butt spliced it in to the duraspark harness.

 

The center plug that my middle finger is touching is the plug for the tachometer. There are 2 wires coming from the cab an one from the harness side. My understanding is that a V8 engine would have had 2 wires coming into this plug from the harness side, but since mine is an I6 I only have one wire. In my case, my donor harness didn’t have a tach wire/plug. I still don’t know why. I cut the “engine side” plug out of my TFI harness, plugged it back in, the I spliced the green wire coming out of it into the green wire right next to it coming out of the 4 wire plug at bottom right. Tach works.

 

The top left connector is the “two wire plug” into my module. It plugged right up. For some reason, there are 3 wires coming into it from the cab. The duraspark only uses 2 of them, and my TFI harness only used the same two wires. I don’t understand what that 3rd conductor is for. If anyone knows, Im curious for sure.

 

Finally, the top right connector is the 4 wire connector to the module. This one just plugged up with no funny business, other than needing to splice in the tach wire as mentioned above.

 

All of the other wires for your duraspark harness should go to your engine. Unless youre doing a points -> DS2 upgrade, then it might be different. Maybe someone with more experience can chime in on that one.

[StraightSix]

FordF843 and Jim,

Thanks for contributing pictures of your vehicles to the thread. Hopefully all of this will help someone else do their Duraspark 2 upgrade. Its alarming how many posts on the duraspark upgrade have been written but don’t seem to have their pictures intact. Here is a picture of mine after completing the upgrade –

The bottom plug (that Im holding in the picture) has 4 conductors coming from the cab. In my original TFI harness, the 4rth conductor went to a blank plug and thus didn't do anything. The other 3 wires are bat + to the coil, the water temp sender, and the oil pressure sender. This is one of the ones that gave me fits, because my donor harness didn't have this plug, it had that bizarre gray square plug. I cut the “engine side” of that connector out of my TFI harness and butt spliced it in to the duraspark harness.

 

The center plug that my middle finger is touching is the plug for the tachometer. There are 2 wires coming from the cab an one from the harness side. My understanding is that a V8 engine would have had 2 wires coming into this plug from the harness side, but since mine is an I6 I only have one wire. In my case, my donor harness didn’t have a tach wire/plug. I still don’t know why. I cut the “engine side” plug out of my TFI harness, plugged it back in, the I spliced the green wire coming out of it into the green wire right next to it coming out of the 4 wire plug at bottom right. Tach works.

 

The top left connector is the “two wire plug” into my module. It plugged right up. For some reason, there are 3 wires coming into it from the cab. The duraspark only uses 2 of them, and my TFI harness only used the same two wires. I don’t understand what that 3rd conductor is for. If anyone knows, Im curious for sure.

 

Finally, the top right connector is the 4 wire connector to the module. This one just plugged up with no funny business, other than needing to splice in the tach wire as mentioned above.

 

All of the other wires for your duraspark harness should go to your engine. Unless youre doing a points -> DS2 upgrade, then it might be different. Maybe someone with more experience can chime in on that one.

Udpates! The factory intake, exhaust, carburetor, and the EEC-IV harness have been removed along with other associated equipment like the EGR.

At this point Im waiting on my new manifold studs to arrive (3/8-16 grade b7 2” studs from mcmaster carr), and I need to plug the holes in my efi manifolds. I have ordered M18-1.5 plugs for the O2 sensor holes because that’s what the internet seems to think I need. They should arrive today. There was much more uncertainty about the right plug for the EGR port. My manifold still has that bushing/adapter in it that looks like it takes an 1”+ plug. Ive read that if you get that out a ¾” pipe plug will plug it. Can anyone confirm or deny this? Anyways, plug the exhaust manifold holes, weld up the new exhaust ( part numbers for the collector pipe, muffler and tail pipe coming soon), fill in the hole in my water heat spacer, figure out my carburetor, figure out the throttle cable and cruise control throttle, and I think Ill be close to a running truck again!

As a matter of interest, I sprayed all of the manifold bolts down with Kroil a few minutes before attempting to remove them. When we got the manifolds off #1 intake port on the head had Kroil in it that must have gone through that crack in the runner.

Ok.. I sorta hate to do it, but here is my “monster sized list of carburetor questions”. For now, Im not too concerned about jets or anything like that. They are 47F jets if anybody is interested, and it’s a 1.08 venturi carb. That seems close enough to correct that Im going to roll with it, atleast initially.

I have a few questions. First off, can anyone definitively Identify the carb? I assume that it’s a 2150 because its got motorcraft cast into it and not autolite, but its missing a lot of the features that the 2150s picked up over the years. perhaps an early model?

There is also the issue of the choke. I now understand that I have a combo electric + hot air choke. I don’t think there is any reasonable way for me to supply the choke mechanism with hot air. Will the “electric component” of the choke be enough to operate it in a desirable way, or does it really need the hot air to work right? If it needs the hot air, Im probably going to have convert the choke to a full electric choke or to a manual choke. Between the two, I don’t have a super strong preference. Could I just plug the hot air holes in the choke body and put the E-choke off of my carter carburetor on the 2150? That seems like a really convenient option and it preserves the function of an electric choke. Alternately, In not really opposed to installing a mechanical choke. It doesn’t seem that difficult, and Ive already got a big hole in the firewall where I pulled out all of the wires from the EEC-IV.

Finally, I have some vacuum hose questions. Ill have 4 hoses. Brake booster, timing advance, cruise control, and PCV. I know the brake booster needs to go to manifold vacuum. Should I find a pipe plug with a hose barb on it and thread it directly into the Offenhauser intake manifold? There are two pipe thread holes on the side of the manifold that seem like they would be good for this but I dont know that I can recall seeing anyone use them. Im pretty sure that the timing advance hose needs to go to the vacuum barb that is under and slightly forward of the choke mechanism (right next to the passenger side forward mounting bolt hole). I blew air into that hole and operated the throttle plates, the sound seemed to change. Thoughts? I have no idea where to land the cruise control hose. On my carter carb it landed in a really bizarre place near the choke. Im at a loss on this one, any advice will be greatly appreciated. Finally, the PCV. My plan is to get a combo breather/oil cap and let the engine “breathe in” through there. Where does the line coming out of the PCV need to land? On the air cleaner?

As always, thanks for reading, and thanks for all of the advice!

[ArdWrknTrk]

Udpates! The factory intake, exhaust, carburetor, and the EEC-IV harness have been removed along with other associated equipment like the EGR.

At this point Im waiting on my new manifold studs to arrive (3/8-16 grade b7 2” studs from mcmaster carr), and I need to plug the holes in my efi manifolds. I have ordered M18-1.5 plugs for the O2 sensor holes because that’s what the internet seems to think I need. They should arrive today. There was much more uncertainty about the right plug for the EGR port. My manifold still has that bushing/adapter in it that looks like it takes an 1”+ plug. Ive read that if you get that out a ¾” pipe plug will plug it. Can anyone confirm or deny this? Anyways, plug the exhaust manifold holes, weld up the new exhaust ( part numbers for the collector pipe, muffler and tail pipe coming soon), fill in the hole in my water heat spacer, figure out my carburetor, figure out the throttle cable and cruise control throttle, and I think Ill be close to a running truck again!

As a matter of interest, I sprayed all of the manifold bolts down with Kroil a few minutes before attempting to remove them. When we got the manifolds off #1 intake port on the head had Kroil in it that must have gone through that crack in the runner.

Ok.. I sorta hate to do it, but here is my “monster sized list of carburetor questions”. For now, Im not too concerned about jets or anything like that. They are 47F jets if anybody is interested, and it’s a 1.08 venturi carb. That seems close enough to correct that Im going to roll with it, atleast initially.

I have a few questions. First off, can anyone definitively Identify the carb? I assume that it’s a 2150 because its got motorcraft cast into it and not autolite, but its missing a lot of the features that the 2150s picked up over the years. perhaps an early model?

There is also the issue of the choke. I now understand that I have a combo electric + hot air choke. I don’t think there is any reasonable way for me to supply the choke mechanism with hot air. Will the “electric component” of the choke be enough to operate it in a desirable way, or does it really need the hot air to work right? If it needs the hot air, Im probably going to have convert the choke to a full electric choke or to a manual choke. Between the two, I don’t have a super strong preference. Could I just plug the hot air holes in the choke body and put the E-choke off of my carter carburetor on the 2150? That seems like a really convenient option and it preserves the function of an electric choke. Alternately, In not really opposed to installing a mechanical choke. It doesn’t seem that difficult, and Ive already got a big hole in the firewall where I pulled out all of the wires from the EEC-IV.

Finally, I have some vacuum hose questions. Ill have 4 hoses. Brake booster, timing advance, cruise control, and PCV. I know the brake booster needs to go to manifold vacuum. Should I find a pipe plug with a hose barb on it and thread it directly into the Offenhauser intake manifold? There are two pipe thread holes on the side of the manifold that seem like they would be good for this but I dont know that I can recall seeing anyone use them. Im pretty sure that the timing advance hose needs to go to the vacuum barb that is under and slightly forward of the choke mechanism (right next to the passenger side forward mounting bolt hole). I blew air into that hole and operated the throttle plates, the sound seemed to change. Thoughts? I have no idea where to land the cruise control hose. On my carter carb it landed in a really bizarre place near the choke. Im at a loss on this one, any advice will be greatly appreciated. Finally, the PCV. My plan is to get a combo breather/oil cap and let the engine “breathe in” through there. Where does the line coming out of the PCV need to land? On the air cleaner?

As always, thanks for reading, and thanks for all of the advice!

Positive crankcase ventilation has to go to full manifold vacuum.

If your 2150 doesn't have a big port in the base flange perhaps you ought to look for a carb spacer with that port sticking out of it.

Motorcraft and Holley carbs have interchangeable choke coils.

I believe the YF's are wound the opposite way.

So a Motorcraft choke will have a single bullet connector for (black/white) 7V stator power.

A Holley electric choke element will have 12V+ and ground spade terminals.

 

[StraightSix]

Positive crankcase ventilation has to go to full manifold vacuum.

If your 2150 doesn't have a big port in the base flange perhaps you ought to look for a carb spacer with that port sticking out of it.

Motorcraft and Holley carbs have interchangeable choke coils.

I believe the YF's are wound the opposite way.

So a Motorcraft choke will have a single bullet connector for (black/white) 7V stator power.

A Holley electric choke element will have 12V+ and ground spade terminals.

Thanks Jim!

Ill put the pvc valve to full manifold vacuum then. There is a pretty good size thread port on the back face of the base flange on the carb (2nd carb picture). I have a brass fitting with a hose barb to match that hole, so it seems like that would be a good spot for the PCV.

Id rather use a 7v electric choke so that I can just plug it in to the existing 7v line from the alternator stator. So I should be looking for a motorcraft electric choke for a 2100/2150? I take it that the one thats already on there is presumed insufficient? And Ill need to plug the hole for the hot air line on the choke, but where is the "other end" or that port? I guess it probably doesnt have to be plugged..

Thanks for the help!

[1986F150Six]

Motorcraft and Holley carbs have interchangeable choke coils.

I believe the YF's are wound the opposite way.

So a Motorcraft choke will have a single bullet connector for (black/white) 7V stator power.

A Holley electric choke element will have 12V+ and ground spade terminals.

Jim, would this be what is needed?

https://www.ebay.com/itm/1983-1984-Ford-Motorcraft-2Bbl-2150-Carburetor-Electric-Choke-Thermostat/254024586984?hash=item3b250b96e8:g:4ToAAOSw~5ZcWIbr

 

[ArdWrknTrk]

Motorcraft and Holley carbs have interchangeable choke coils.

I believe the YF's are wound the opposite way.

So a Motorcraft choke will have a single bullet connector for (black/white) 7V stator power.

A Holley electric choke element will have 12V+ and ground spade terminals.

Jim, would this be what is needed?

https://www.ebay.com/itm/1983-1984-Ford-Motorcraft-2Bbl-2150-Carburetor-Electric-Choke-Thermostat/254024586984?hash=item3b250b96e8:g:4ToAAOSw~5ZcWIbr

I believe so!

I don't think there's really any difference with the one found on 4V's like the 4180, but that listing seems priced right.

[StraightSix]

I believe so!

I don't think there's really any difference with the one found on 4V's like the 4180, but that listing seems priced right.

Thanks guys! So it really is just as simple as putting a "real electric choke" in place of the electric choke from my electric+hot air choke? And probably plugging that hot air intake hole? Thanks a bunch, I just assumed there would be more to it than that

[ArdWrknTrk]

Thanks guys! So it really is just as simple as putting a "real electric choke" in place of the electric choke from my electric+hot air choke? And probably plugging that hot air intake hole? Thanks a bunch, I just assumed there would be more to it than that

There is a tiny amount of vacuum present to draw air through the choke stove.

The carb will be tuned to run with this 'leak' just like it's tuned to run with the PCV.

But you don't want cold air drawn into the choke coil, so you should cap/plug it.