Cool, I didn't realize they were constant flow injectors. Sounds like a better version of the EFI system chrysler came out with in 50's. I know there's at least 1 still running with the original efi system.

Ok so I looked closely at my tophat/computer/maf. It says remanufactured. I think all 3 years of this tbi system used the same components, so hopefully this one works on my system. The previous owner may have had problems with the original at some point and got this as a replacement.

Because I've never owned one of these, Im wondering if anyone here knows if this unit is plug and play or if it was some update that chrysler put out to fix tbi issues and if it possibly requires other updated parts. Im going to slap it all together on saturday after I disassemble and clean out all components that have old fuel in them, and see if it will fire up with fresh gas and battery.

Im also going to check my local hardware store for some flat stock foam/rubber gasket material that I can cut to size and replace any old gaskets that may cause a leak. the tophat still has the thick rubber seal on top in good shape, so I think Im ok there. My goal is to eliminate any possible vacuum leaks in the system and clean out any crud/varnish from old gas. That way if I have problems I can eliminate bad gas and vacuum leaks right off the bat

Im still amazed that as smart as chrysler engineers were, why on earth did they put the MAF in the air cleaner??? 1st of all, at that time, most FI cars were still using MAP sensors, but chrysler used some pretty advanced/efficient components for a fi engine in 1981, so with all that engineering going into it, why would they place the majority of these parts in compromising areas, like hard to seal air cleaner assemblies that sat right on top of the engine? Not to mention the ignition control computer sitting in the air cleaner as well getting shook around constantly while the engine was running. And then relying on a screw to ground the power cut of module to the fender.

I guess I really cant talk smack about it, not like Im an engineer nor have I ever designed an FI system, but some things just seem like a no brainer. maybe they were stuck with budget constraints and were forced to modify existing parts instead of building new parts like throttle bodies that would house the MAF, and feul/spark control computers relocated to engine bay or cabin

They may not have known any better. Think about it, just a few years earlier they came out with the lean burn system with the ecu on the air cleaner and by the time this system was being designed those lean burn cars were still running fine.

Got everything cleaned up and assembled. put about 4 gallons of premium fuel and a bottle of seafoam in the tank, The engine turns over nice and strong, and Im getting spark, but not a drop of fuel. I unplugged the asdm and jumped the contact of the large blue wire to the contact of large green wire. I dont know exatly what this does but I read about it on theimperialclub.com. When I turned the key to on I could hear a fuel pump running, couldnt tell which though, still no start. But it was late and I'd had a few beers and was done working on the car for the night.

I think the pump I heard was the control pump in the hsa assembly. I will have to have someone turn the key while I look down the throttle body to see if its even priming. I havent checked out enough of the possible problems yet to make an educated guess, but I think either the pump in the tank isnt working, the duel filters are clogged, or the control pump or entire hsa assembly isnt working right.

When I go back out Ill check everything in that order. Does anyone know if the fuel computer also controls the in tank pump or just control pump?

Ok the in tank pump is working fine. The previous owner had spliced another 3/8 hose with a valve on it to the fuel feed line that feeds the control pump in the hsa assembly. So with the asdm bypassed and the key turned to on position, I opened valve and fuel sprayed out. I tested the voltage to the control pump and it was 6 volts. I know it's a constant flow system and the speed of the control pump is controlled by alternating voltage, but not sure if 6 volts is to low.

What I cannot figure out is if the pump is dead or not getting enough voltage because not one drop of fuel is coming out of the 4 little rails that spray fuel into the throttle bores. I know the rails are fine because I cleaned them out with carb cleaner and they flowed fine.

Well I unhooked the little metal fuel line that goes from the control pump to the fuel injection assembly. Turned the key and after about 2 seconds it starts steadily pouring a small volume of fuel. It's not a dribble but definitely not high pressure. Should be enough pressure to have fuel come out of the rails. After that I hooked everything back up put the lid on the top hat and with the asdm bypassed I turn the key and the car started right up and sounded perfect. It was running off the fuel that had poured out of the feed line to the fuel injection rails when I had it off so it only ran for a little while and then it turned off when it ran out of fuel. So my next step is to take off the fuel injection unit and see why the fuel is getting caught up inside and not coming out the rails. Maybe it has its own pressure requirements before it lets the fuel come out.

But with the amount of fuel that I described that poured out of the feed line to the fuel injection unit, does that sound like the right amount of fuel that should be flowing? Is the control pump possibly dead and that small amount of fuel that came out just just the remainder of the fuel being fed from the tank pump after it pushes its way through the Dead control pump?

Took apart the fuel injection unit again. There are 2 needle and seat valves like in a carburetor fuel bowl. I took them out and opened them manually with my finger, so they aren't frozen up. Looks like there just isn't enough fuel pressure to overcome their spring pressure removed them and reinstalled the fi unit. Car fired up and although it idled high and didn't feel right, it ran and drove.

So it's probably a fuel pressure issue, My next step is to finally buy a fuel pressure tester and see exactly what pressure I'm getting out of the tank pump and the control pump and see where I'm at.

At least I know the engine runs. Can't wait to figure this out and start driving it, the car is incredibly comfortable and was well taken care of

Sorry I can't be much help but I always find it interesting when people get old unusual induction setups running. Keep us updated, it sounds like you are close.

Success, sort of. Taking both needle and seats out floods the car almost immediately. Putting them both in , I get no fuel at all. I took out the needle and seat for the rail with the small sprayers, and left in the needle and seat for the large sprayers.

Car fires right up and runs and drives. It's not as smooth obviously as it could be because the fuel is basically just pouring out of the fuel rail instead of a nice spray pattern. But it works and now it runs and drives. That is until it finally gets flooded then it stops and I have to wait for it to dry or plug the asdm back in and fire up the car and burn up all the fuel that's in the intake then unplug the asdm and bypass it again and then the car fires right back up and drives.. until it floods lol.

This is a decent mickey mouse fix until I can find the cause of my low fuel pressure. Or gather the intake and carb I need for the conversion.

I'm going to get the conversion parts anyways actually, just in case I cant find the parts I need for repairs to the efi.

I'll probably run a switch that connects the green and blue asdm wires and run the switch to the cabin so I can turn it turn off the bypass when I flood, then burn it off, then flip the switch and bypass it again and start it up and drive! It's a temporary mickey mouse fix but it is better than nothing

MY GOD, These cars are insane.

So, I settled with the fact that I would be driving it for a little while in the condition I described above. At peace with that fact, I start doing other things like putting the door panel back on, replacing the fuse for the horn, playing with the gauge cluster fuse (the gauge is fully digital, but looks all scrambled and weird, just another issue to deal with I guess). There is this hissing noise whenever you open the door and the gauge cluster lights up, and continues after the car starts. Well, take out the 4 amp gauge cluster fuse and the hissing goes away. Not sure what the hell that is, but I did notice at least 3 vacuum pods under the dash. So I also replaced the front passenger caliper which was rusted and locked up, bled the brake line, and finally put some under dash wire harness connectors back on their mounts (they were just hanging). I finally installed the under dash cover and now Im tired and I want to enjoy my labor and go for a cruise.. well, a cruise that involves the engine flooding every ten minutes, but whatever I know I just undo my jumper on the asdm and then crank the car and burn up the flooded gas, then re-jumper the asdm. Its worth it after a day of labor.


SO, I get in the car. Apparently an exhaust leak has begun somewhere, cause I can really hear it now. I take the car out from my coltesac, and give it some gas, it hesitates and BAM backfires through intake, so I just take it slow and easy. The driving characteristics begin to change. hard to explain, but it ends up with the car dying.

So I get out and take the jumper off the asdm and plug the asdm back in its connector as usual. I get in the car, turn the key and after a couple seconds it turns on and I sit and wait for it to die. But.... it doesnt die... it keeps running! I was mystified and scared at the same time. Could it really have solved itself??? I shut the hood, and go driving. peppy acceleration, doesnt run smooth but it runs. I drove it all over. It doesnt like hills, but does great on the flat roads.

So apparently the EFI decided its going to work again. I get home and get out to investigate exhaust leak. I opened the hood and within seconds my eyes are burning and crying, I backed up.. then looked under the car.. for a few seconds until my eyes begin to burn and cry again. It was running fatty fat pig rich. Must be because I took the needle and seat out, which was necessary at the time, but now is causing it to run super rich. I also had the o2 unplugged for same reason, to help it run better back when the asdm was shutting everything down, so I plug it back in. I turned the car off and called it a night.

Looks like I now have a running driving imperial with a fuel control computer that has decided it likes all the attention Ive been giving her and will now operate correctly when I turn her on.

So tomorrow, I re-install the needle/seat in the FI unit, and take a look at the exhaust. hopefully its just leaking at the connection points so I can solve the problem with some remflex gaskets and be done with it.

Awesome! Keep going! I will probably have to do 3/4 of this stuff when I try to start my '82. FWIW, mine hisses too, I think it is normal, at least to some extent.

Great read! I've heard about this early EFI system but have never seen one and have no experience with them, but I find this very interesting.

I just discovered this thread this morning. We have an 81 Imperial with EFI and runs well. We enjoy it. It can be temperamental at time, and like with any 40 year old car that is driven regularly, requires a lot of periodic fixes. Otherwise we have had good luck and have owned it for 8 years. 139K and likes to be driven a lot. We have crossed the country three times in this car.

Ok, back to square 1.

Looks like I need parts, and more troubleshooting. No thanks. Converting to carb and points vacuum advance distributor. Why points? Because I have one on the shelf.

Heres all the options I can think of for dealing with fuel delivery. I will be left with the stock fuel tank and in tank pump. The pump puts out max about 29psi. It was the control pump on the throttle body that changed the "low" pressure to high pressure, and the control pump is going bye bye.

So, stock tank and in tank pump with lines already in place leading right to top of intake. I need to do this as cheap as possible, Low on funds and this is going to be a daily driver so gotta get it done soon.

Option 1: rewire pump, Use a bypass regulator and regulate psi to eddy carb, sending the rest back through the existing return line.

question: Whats the cheapest regulaor I can accomplish this with? I saw a quick fuel 30-899qft but I dont know if it can handle 29psi. I also saw a tanks inc. regulator rated for 30-70psi input, does that mean it cant handle less than 30 psi? both of those are $75


Option #2 Unplug pump. Install a mechanical fuel pump (cheap!) and pull fuel through the unplugged in tank pump

Question: Some in tank pumps will allow this, in fact chevy guys with tbi camaros have done this when swapping to carb. does anyone know if mine will?

Option #3 install mechanical pump, drop tank, remove pump, extend hose to bottom of tank. I can rig up a sock at the end of hose for extra protection, although my car already has 2 fuel filters between tank and engine.

Option #4 Install exterior low pressure fuel pump and cheaper regulator and pull through tank pump

Option #5 same as #4, just extra step of removing in tank pump and extend hose to bottom of tank

Option #6 Rockauto dodge mirada gas tank $85, sending unit $55, then mechnical fuel pump $20



What do you guys think is best option 1 through 5? Or any I havent thought of? Remember, low dollar

What are you going to do with the old EFI parts ?

SELL THEM

Ok so I waited and got better parts for my conversion:

Proform 66991 kit: vacuum advance 2 wire distributor, 2 prong ballast resistor and 4 pin orange box.

Summit racing 750 vacuum secondary carb with throttle stud adapter and tranny kickdown extension

Edelbrock Performer 2176 Intake with MR Gasket Ultra Seal intake gasket .060

NGK GR4 plugs

delphi mechanical fuel pump.


Got most of the wiring sorted out, and I have a question about the ballast resistor and starter relay. My current Ballast Resistor is 5 prong with 3 different resistances, and the starter relay is 6 prong.

I'd like to simplify and clean up my wiring more, I dont mind the work. I have the 1981 FSM for my imperial and have followed the wiring diagram. I've already removed everything EFI, but I'd like to ditch the 5 prong ballast resistor and 6 prong Starter relay and go with a simpler setup from say a 72 Chrysler or dodge.

Im already getting a new 2 prong ballast resistor with my proform kit, can I get a starter relay from a 72 318 dodge and follow the 72 wiring diagram to alter my ignition?

Here's a picture of my stock S.R. and B.R.

Bump

run the ign1 (run) blue wire to the upstream end of the ballast and T'd to the blue/yellow ECU pentastar connector terminal (might be solid blue). run the ign2 (crank) brown wire to the downstream end of the ballast. connect that downstream end of the ballast to the coil positive primary terminal. connect the coil negative primary terminal to the black/yellow ECU pentastar connector wire. With the blue/yellow ECU terminal held at 9 0'clock, run the 11 0'clock ECU terminal (might be tan with a black tracer) to the male metal terminal on the ECU half of the zigzag pull apart zigzag connector. the female counterpart on the pickup zigzag will be black, the other should be orange/orange. On the SR, duplicating the early stuff: I would run the ST terminal on the ign sw to the "ign" terminal & the "sol" large brown wire down to the starter solenoid & run the "grn" terminal to the NSS switch or permanently ground it as desired. EDIT we might (highly likely) be able to keep the current SR & just delete the one or two wires that wont be used when retrofitting to the earlier setup, we'd just need to find out what goes to where on the FI for a start.