Unsure of how to move forward with 81 EFI Imperial

Jimmy Jippy

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I bought a 81 Imperial a few months back and it's made a mighty fine lawn ornament, but now that I get even a hint of sunshine, I want to work on it and get it all prettied up for summer, but here's my problem: I'm not sure if I should switch to Carb or not.

Currently, vehicle does not run unless gas is dribbled in from the top, elderly woman who previously owned it had the gas tank pierced by something and it sat in her garage for 30 odd years. It's all electronically fuel injected and fired right up no problem even after sitting for such a long time, also no ticking or odd noises, but just that issue with the fuel tank. I was told a fuel pump and fuel cell could be iffy due to the "specific" nature of early electronic fuel injection. So now I'm at the crossroads - would it be wise to switch to carb to circumvent problems? or could I actually have a fuel cell hooked up and it won't be an issue? any advice appreciated, apologies if I cannot answer questions and whatnot, this is the first vehicle I've owned that's over 20 years old.
 
You said it started no problem but now requires fuel to be dribbled in. How long did it run before this new problem developed? The hole in the tank, has that been taken care of? What is the condition of the tank (debris getting into EFI system)? What is the fuel pressure up top with key on?

While the quick answer would be "switch to carb!", maybe you can get it to run with the EFI.. I would give it a shot.
 
I've always wondered if the EFI on these cars would work if you swapped in some modern electronics. Switching to a carb I think involved replacing the fuel tank and fuel pump, and you lose functionality of the fuel mileage computer. Several very smart people on this forum, they won't steer you wrong.
 
ONE of the quirks of those EFI systems is that if the TOP of the air cleaner is removed, the mass air flow sensor loses it's signal. So with no signal of air flow through it, the computer thinks the engine has died, so no fuel delivery. MOST people who worked on or traded-for those cars knew of this situation.

Which is why the band clamp around the outer edge of the top of the air cleaner assy, to keep things sealed up so the mass air flow sensor, which is located IN THE SNORKEL of the air cleaner gets a solid air flow "into the engine" signal. Even a cock-eyed/crooked clamped top could result in enough "leakage" from the imperfect top seal to result in flaky running.

In looking at the system, it was hastily-designed by Chrysler Aerospace and configured to have minimal impact on assy line procedures and related costs. In that respect, the system can be installed just like a normal carburetor engine, in many respects, as the bulk of the EFI sensors and such are on the air cleaner base (termed "fuel plate" by Chrysler). It was more of a forced-marketing situation as Lincoln and Cadillac had their own EFI systems, so if Imperial was going to compete, they needed one too.

Going forward . . . it would seem that something like the Holley Sniper EFI family could provide a less-cumbersome system than any OEM EFI back then. Might be able to use the existing fuel supply system and adapt the Holley system to it? They now have 2bbl Snipers, which could be bolt-on situations rather than going to one of their 4bbl systems. This would keep the original "intent" of the car, too, just need a normal Chrysler 400 2bbl air cleaner, painted silver to complete the conversion.

On the cars which were converted to a (basically) Dodge Mirada/Chrysler Cordoba fuel system, some functions on the instrument cluster displays were rendered useless.

Those Imperials had some awfully-high-geared rear axle ratio (2.2?), so any thought of "high performance" is not applicable, but solid, smooth, and economical (but slow) performance can be. Especially when combined with their 5.2L V-8 and 4000lbs.

Just some thoughts,
CBODY67
 
convert it to carb.
dont waste your time & $$ messing about trying to get the original efi working, let alone reliable....... ( ive had 4 btw)
my last 1 had a 4v with dual exhaust and a 3.23 s/g axle from a mirada.
and sequential taillights

81 Imperial 1 (2).jpg
 
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convert it to carb.
dont waste your time & $$ messing about trying to get the original efi working, let alone reliable....... ( ive had 4 btw)
my last 1 had a 4v with dual exhaust and a 3.23 s/g axle from a mirada.
and sequential taillights

View attachment 642666

It is interesting that you have converted 4 of these cars to carbureted vehicles - did you have the conversion package that Chrysler provided to make the changeover or did you just used a Mirada or equivalent to make the changeover, and if the latter I can see how it would be relatively straightforward to just take the fuel system from a Mirada or equivalent to get the engine running easily enough, but did you lose anything in the dash panel function or require a swap of the body wiring harnesses from a Mirada or equivalent to get the instrument panel to be fully functional?

Lastly, I note that you do not list one of these Imperials as being in your current collection, so why did you let them all go apparently? The photo of the white Imperial above is really striking to my eyes and I would have a hard time letting it go if I am interpreting your post correctly. Thanks for any enlightenment.
 
If you do need to convert your car to carb, you may find old tech bulletins for the dealers that had to do the conversion.
 
It is interesting that you have converted 4 of these cars to carbureted vehicles - did you have the conversion package that Chrysler provided to make the changeover or did you just used a Mirada or equivalent to make the changeover, and if the latter I can see how it would be relatively straightforward to just take the fuel system from a Mirada or equivalent to get the engine running easily enough, but did you lose anything in the dash panel function or require a swap of the body wiring harnesses from a Mirada or equivalent to get the instrument panel to be fully functional?

we used mirada/cordoba fifth avenue donor cars.
no chrysler conversion parts, i was told that it was a huge process, with a truck load of parts inc new fuel tank etc arriving at the dealer for each conversion.
i should clarify that i successfully converted 2 - the best was the last, #4, the white 81 which got all the upgrades. it was a non running car that i didnt even attempt to try to get running with the fuel injection.
it came to me from the family who's uncle owned it from it being a couple of years old, supposedly he had bought from the original owner.
not sure why they didnt get it converted under warranty and he had passed away so there was no way of knowing.
they did say that the original owner was very bitter about the car and eventually so was their uncle. both loved the car but hated it as well.
which is probably why uncle never sold it as well as the fact he was not 1 to pass on trouble to another. and why it was in such nice shape, always being garaged.
the usual story of endless breakdowns and repairs.
eventually i was offered the car because they knew of me and the imperials / new yorkers i had owned.
by the time i was offered the car, i was so tired and frustrated with the years long learning & experimenting curve with fuel injected imps that i had already sold off the 3 that i started with.
the 1st 2 cars were rough low mileage (of course) fuel injected cars and the 3rd had had a non dealer 2v conversion. this was what gave us the tips on what to do.
apparently it had the drivetrain from a fifth avenue.
car # 2 got the intake, carb, fuel tank etc from a t-boned 318 cordoba and car # 2 ran pretty well, but it was shabby.
i dont remember how the wiring was dealt with but i dont recall it being a big issue.
i gave up on car #1 after getting car #3, there had been too much time, energy and $ put into it and 1 & 2 gave me insight into why 81-83 imp owners become bitter.
#1 was alot shabbier than # 2, it was light auburn ( beige with a heather cloth interior and always looked dirty.
#2 was mahogany brown with brown leather.
#3 was also light auburn with i think heather leather, could have been cashmere leather - kind of similar.
i sold # 3 to someone who asolutely had to have it, and i sold #1 & 2 as a package.
several years later, around 1996 i was offered the white 81 - nice red leather, moonroof & 2.24 suregrip.
i bought a low mileage shabby mirada donor car mainly for its gas tank and 3.23 suregrip axle, it also had the rear sway bar like the imperials. its 318 was missing, it was a fact 4v car.
the imperial's motor was pulled and gone through and it got the 4v intake from a diplomat rcmp cruiser, mechanical fuel pump and an edelbrock carb was installed. i was always told the fuel injected imperial 318 used 360 heads, i dont know for sure - im sure others would know.
again, i dont recall the wiring being a big deal.
it was a fun car, the dual exhaust gave it a healthy rumble and it was fun at shows when people would comment on the white liberace wedding cake of a car sounding healthier than the barracuda next to it......
i kept it until around 2007.
at that time i was focussed mainly on my 2 sunroof salons and boat tail rivieras.

the dash function that was lost was the distance to empty estimate, and i dont remember if the mpg avg was also lost.
i believe the dealer conversion cars kept those functions.

mark
 
Lastly, I note that you do not list one of these Imperials as being in your current collection, so why did you let them all go apparently? The photo of the white Imperial above is really striking to my eyes and I would have a hard time letting it go if I am interpreting your post correctly. Thanks for any enlightenment.

there were 2 issues for me that made it easy to let go - the driving position.
im 5'10" and at the time was around 230lbs.
the beautiful looking seats were comfortable but after a while i noticed that the seat bottom was too short - it ended closer to my butt than closer to the knee.
road tests of the day mentioned this.
i found this uncomfortable especially after driving 1 of my salons or even the 81 cordoba & mirada i had. the cordoba's seat was more comfortable and more supportive especially towards the knee. i even considered swapping in cordoba seats but that wouldnt have dealt with issue #2.
the imperial's seat just didnt extend far forward enough - heres a pic of the mirada seat.

1707332035619.jpeg


and issue # 2 was that the steering wheel is offset to the right.
the combination of the too short seat and steering wheel not being centred in front of the driver really began to irritate me, especially after driving the salon or rivieras. ( ive prob had 7 boat tails).

i nearly bought a sinatra imp last year but as soon as i sat in it the seating /driving position irritation came back........
 
No one has mentioned this or answered the question...

or could I actually have a fuel cell hooked up and it won't be an issue?
A fuel cell is not a good idea and whoever mentioned that to you is somebody that you should not take advice from.

You'll have issues matching the gas gauge, it will take up a lot of trunk space and be a PITA to put gas in. Plus it's an Imperial! Not a race car.

Typical fuel cell.

1707336973770.png
 
there were 2 issues for me that made it easy to let go - the driving position.
im 5'10" and at the time was around 230lbs.
the beautiful looking seats were comfortable but after a while i noticed that the seat bottom was too short - it ended closer to my butt than closer to the knee.
road tests of the day mentioned this.
i found this uncomfortable especially after driving 1 of my salons or even the 81 cordoba & mirada i had. the cordoba's seat was more comfortable and more supportive especially towards the knee. i even considered swapping in cordoba seats but that wouldnt have dealt with issue #2.
the imperial's seat just didnt extend far forward enough - heres a pic of the mirada seat.

View attachment 642786

and issue # 2 was that the steering wheel is offset to the right.
the combination of the too short seat and steering wheel not being centred in front of the driver really began to irritate me, especially after driving the salon or rivieras. ( ive prob had 7 boat tails).

i nearly bought a sinatra imp last year but as soon as i sat in it the seating /driving position irritation came back........
I find all that interesting. I never had one, never sat in one, always wanted one. Likely not now.
If you had trouble at 5'10" I'd certainly have trouble at 6'4".
I've had 4 Miradas and 1 Cordoba. I need another, gotta be an 82 T bar car.
But damn those Imps are cool as Hell.
 
there were 2 issues for me that made it easy to let go - the driving position.
im 5'10" and at the time was around 230lbs.
the beautiful looking seats were comfortable but after a while i noticed that the seat bottom was too short - it ended closer to my butt than closer to the knee.
road tests of the day mentioned this.
i found this uncomfortable especially after driving 1 of my salons or even the 81 cordoba & mirada i had. the cordoba's seat was more comfortable and more supportive especially towards the knee. i even considered swapping in cordoba seats but that wouldnt have dealt with issue #2.
the imperial's seat just didnt extend far forward enough - heres a pic of the mirada seat.

View attachment 642786

and issue # 2 was that the steering wheel is offset to the right.
the combination of the too short seat and steering wheel not being centred in front of the driver really began to irritate me, especially after driving the salon or rivieras. ( ive prob had 7 boat tails).

i nearly bought a sinatra imp last year but as soon as i sat in it the seating /driving position irritation came back........
there were 2 issues for me that made it easy to let go - the driving position.
im 5'10" and at the time was around 230lbs.
the beautiful looking seats were comfortable but after a while i noticed that the seat bottom was too short - it ended closer to my butt than closer to the knee.
road tests of the day mentioned this.
i found this uncomfortable especially after driving 1 of my salons or even the 81 cordoba & mirada i had. the cordoba's seat was more comfortable and more supportive especially towards the knee. i even considered swapping in cordoba seats but that wouldnt have dealt with issue #2.
the imperial's seat just didnt extend far forward enough - heres a pic of the mirada seat.

View attachment 642786

and issue # 2 was that the steering wheel is offset to the right.
the combination of the too short seat and steering wheel not being centred in front of the driver really began to irritate me, especially after driving the salon or rivieras. ( ive prob had 7 boat tails).
i nearly bought a sinatra imp last year but as soon as i sat in it the seating /driving position irritation came back........

Thanks very much Mark for the comprehensive review of your overall thoughts and the downsides of those cars as I am confident I would find the same irritations as you did if I had spent some time in the driver seat. Given the issues with converting the fuel injection as well, I can see why there are so many on the market. I think your comments will cause me to drop one of those off my "would to like to own someday" list. I also believe owning a Mirada or Cordoba instead would be a better overall choice if one can be found with low miles and garage kept all its existence.

Steve
 
I'm 5'9" and I thought the seats in my Mirada were very comfortable. Never had any issues with the seats or driving position or anything. One thing I've always worried about with the Imperial (assuming it's already converted to carb.) is that if the digital instruments went faulty, it'd be difficult and expensive to repair. But I only just now realized that you could probably just swap the whole instrument panel from a Mirada or Cordoba into an Imperial. I don't see any reason why you couldn't.

Now that I re-read that last post, am I seeing that the Mirada/Cordoba seats are different/better than the Imperial seats? I had no idea!
 
The Cordoba buckets fitted me like a pair of slippers.
I'm guessing they were all b body buckets under the fabric.
 
I just bought a '81 Imperial. It is rough, ready, and unmolested. I'm going to give the fuel injection the 15 minutes it deserves for sitting on there for 43 years. Then it is getting removed, period. My intention is to replace my wife's 200k+ mileage Jeep with this car for long distance trips. So everything that goes on the car will be reliable, readily available, and easy to diagnose /not covered in plastic shrouding.
That F.I. system is the poster child of unreliable and a parts mess.
On top of all that there is no on board diagnostics of any type. Not making a hot rod out of it just a fuel mileage cruiser, so the rear and trans are already in place for that.
 
I just bought a '81 Imperial. It is rough, ready, and unmolested. I'm going to give the fuel injection the 15 minutes it deserves for sitting on there for 43 years. Then it is getting removed, period. My intention is to replace my wife's 200k+ mileage Jeep with this car for long distance trips. So everything that goes on the car will be reliable, readily available, and easy to diagnose /not covered in plastic shrouding.
That F.I. system is the poster child of unreliable and a parts mess.
On top of all that there is no on board diagnostics of any type. Not making a hot rod out of it just a fuel mileage cruiser, so the rear and trans are already in place for that.
What are your plan's for the Rear and Trans ?
 
What are your plan's for the Rear and Trans ?
I'm leaving both. Refresh on the trans, because it's never been apart and seals are I'm sure very hard and not pliable. Rear end is 7.25 with im told 2.21 ratio. Works out to around 2200rpm at 70 mph with 215/70R15 tires or in that ballpark. That should be about perfect for 20+ mpg highway with A/C blowing ice cold.
Trans is a 999 so has the 2.77 first gear, and I believe lock up converter.
Doing math 2.77x2.21=6.122
2.45x2.94=7.203
So unless your running a 3.23 or better (more than that is terrible on highway) your pulling out gear from red light is hardly worse.
IMHO anything 3.23 and above needs overdrive to run 70+ mph all day long, that's a different argument.
 
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