Weighing induction/ignition options...

[APF1984BII]

I'm just about to set the intake manifold on top of the 2.8 in my '84, so I'm at crunch time to figure out - am I going to go back with the stock TFI distributor and electronic Motorcraft 2150 carb, or do the Duraspark/Holley carb thing, or do the fuel injection thing? Cost, simplicity and reliability are all factors that will influence the decision, but others will come into play, such as: will any of the options allow me to delete the ThermActor system, which needs quite a few spendy parts to restore it? And, does one give more bang per buck than the others? Any insight based on experience with any or all of these options would be most welcome. Thanks in advance - Chris

 

[tw205]

I'm just about to set the intake manifold on top of the 2.8 in my '84, so I'm at crunch time to figure out - am I going to go back with the stock TFI distributor and electronic Motorcraft 2150 carb, or do the Duraspark/Holley carb thing, or do the fuel injection thing? Cost, simplicity and reliability are all factors that will influence the decision, but others will come into play, such as: will any of the options allow me to delete the ThermActor system, which needs quite a few spendy parts to restore it? And, does one give more bang per buck than the others? Any insight based on experience with any or all of these options would be most welcome. Thanks in advance - Chris

I have two BIIs with those 2.8 engines so I quest I have some experience. The first one I worked on was still in original configuration. It needed repairs to the thermactor system and I believe I disconnected all of it. Pinched the ports off at the back of the head and deleted the air pump with no reaction from the CEL. With pump deleted the alternator v-belt will be the same size as the power steering.
Eventually both my 2.8s have duraspark ignition and regular motor craft 2150 carb. Relatively easy job but it seems in recent years the distributor has become a white whale. However it seems the point type distributor has been successfully used and still available.

 

[APF1984BII]

Thanks, tw205. Exactly the kind of feedback I'm hoping for. If I'm remembering things right, there's not an O2 sensor of any sort in the exhaust system, so nothing to report rich/lean exhaust to the ECM. Also, correct me if I'm mistaken, but the factory-issue Motorcraft carb only has a throttle position sensor (right side), an idle air control (rear) and an idle speed solenoid (front left). I think there's an Aisin carburetor (maybe used on the 4 cylinder?) that is far more invasive with the monitoring and actuating... They may both call themselves "feedback carburetors", though.

 

[tw205]

Thanks, tw205. Exactly the kind of feedback I'm hoping for. If I'm remembering things right, there's not an O2 sensor of any sort in the exhaust system, so nothing to report rich/lean exhaust to the ECM. Also, correct me if I'm mistaken, but the factory-issue Motorcraft carb only has a throttle position sensor (right side), an idle air control (rear) and an idle speed solenoid (front left). I think there's an Aisin carburetor (maybe used on the 4 cylinder?) that is far more invasive with the monitoring and actuating... They may both call themselves "feedback carburetors", though.

Yes, your carb description is correct. I have been able to get mine to run with feedback carb but not as well as the standard carb. I haven’t tried the Holley equivalent but wanting to try it.
The points type distributor sounds like an even simpler solution than the duraspark. I wish I had thought it thru and tried it on the last swap. Not that the duraspark isn’t good. Just for simplicity.
Are you running a manual transmission? A4LDs need some changes to make them work without the ECM. I have one of each and use a simply toggle switch to activate my OD.

Edit: I believe there is a sensor on the driver side exhaust manifold.

 

[APF1984BII]

Ooh, I think you're right about the driver's side O2 sensor, tw205. Looking back, I remember NOW twisting one out of the left manifold. My transmission is the factory 3-speed automatic. Really would like to slip in an A4LD, but after doing the reliability rebuild featured on this forum. Think I'd like to put it in behind a pushrod 4.0, too...

 

[APF1984BII]

Whoops - my mistake! The A4LD rebuild appears on explorerforum.com, by Glacier991 (another Chris). I haven't read all the way through it, but it seems like Chris researched all the weak points of the transmission and substituted more-heavy-duty components where possible. A Google search for "A4LD transmission rebuild" will pop up his thread.