commando1
Old Man with a Hat
Don't let this EFI disaster be confused with LeanBurn that came out years earlier.
'81 IMPERIAL EFI CONVERSION TO CARB - ANYONE TRY THIS?
- Thread starter Dobalovr
- Start date
Carmine
Old Man with a Hat
I've had three of these cars. The first one I converted to carb when I was 17. It's not hard. Remove EFI components. Install conventional distributor, carb and intake. Find ign. hot and start wires. Wire up the 4-wire connector to standard electronic box, one is start feed, one is coil. 50% of the wiring just goes to the distributor! Seriously this isn't hard. Just disconnect all the EFI wiring. You need not remove it.
That solves your spark. You can draw through the in-tank pump, but you should probably drop the tank and at least make sure the filters are clean. Just wire a low-pressure electric pump the same way you would any other carb/elect. pump car.
There is no black magic on the dash. The swap just gave you a different calibration to make the "mile per gallon/miles till empty" gadgets work. The digital gauge works as normal, just a regular sending unit. The speedo runs from a mechanical speed sensor. Nothing changes. Everything else is an idiot light.
All of this said, I only suggest this hackery to save the car. It's not impossible to make the system work. My second car kept the EFM. The pump plate is the only real tough part. The problem most people have with these cars is that there is no tolerance for vacuum leaks (or variances in air/fuel mix). It doesn't know how to deal with that, which is why it won't run without the air cleaner lid tight, and it's why they often run better with the o2 sensor disconnected. It defaults to "open loop" mode which is fuel-rich.
Here's my third example, which I sold a few years back. I might have kept it if the EFM was still on it... To me that's part of the character of the car.
That solves your spark. You can draw through the in-tank pump, but you should probably drop the tank and at least make sure the filters are clean. Just wire a low-pressure electric pump the same way you would any other carb/elect. pump car.
There is no black magic on the dash. The swap just gave you a different calibration to make the "mile per gallon/miles till empty" gadgets work. The digital gauge works as normal, just a regular sending unit. The speedo runs from a mechanical speed sensor. Nothing changes. Everything else is an idiot light.
All of this said, I only suggest this hackery to save the car. It's not impossible to make the system work. My second car kept the EFM. The pump plate is the only real tough part. The problem most people have with these cars is that there is no tolerance for vacuum leaks (or variances in air/fuel mix). It doesn't know how to deal with that, which is why it won't run without the air cleaner lid tight, and it's why they often run better with the o2 sensor disconnected. It defaults to "open loop" mode which is fuel-rich.
Here's my third example, which I sold a few years back. I might have kept it if the EFM was still on it... To me that's part of the character of the car.
Thank you! This is what I was thinking. Slightly more complicated than a lean burn conversion but very doable. Basic stuff fuel air spark in my mind. It was the wiring overlays that freaked me out. Low pressure fuel pump will work with the filter system is a concern but seeing as how i have all the parts sitting in a 79 Cordoba parts car maybe worth the effort.
78Brougham
"Chump"
What'd he say???
78Brougham
"Chump"
I agree, if you go on for fmj bodies only and other sites, these have been converted for years. Or repaired, I loved this version of imperial and hope to get one one day.
78Brougham
"Chump"
I've had three of these cars. The first one I converted to carb when I was 17. It's not hard. Remove EFI components. Install conventional distributor, carb and intake. Find ign. hot and start wires. Wire up the 4-wire connector to standard electronic box, one is start feed, one is coil. 50% of the wiring just goes to the distributor! Seriously this isn't hard. Just disconnect all the EFI wiring. You need not remove it.
That solves your spark. You can draw through the in-tank pump, but you should probably drop the tank and at least make sure the filters are clean. Just wire a low-pressure electric pump the same way you would any other carb/elect. pump car.
There is no black magic on the dash. The swap just gave you a different calibration to make the "mile per gallon/miles till empty" gadgets work. The digital gauge works as normal, just a regular sending unit. The speedo runs from a mechanical speed sensor. Nothing changes. Everything else is an idiot light.
All of this said, I only suggest this hackery to save the car. It's not impossible to make the system work. My second car kept the EFM. The pump plate is the only real tough part. The problem most people have with these cars is that there is no tolerance for vacuum leaks (or variances in air/fuel mix). It doesn't know how to deal with that, which is why it won't run without the air cleaner lid tight, and it's why they often run better with the o2 sensor disconnected. It defaults to "open loop" mode which is fuel-rich.
Here's my third example, which I sold a few years back. I might have kept it if the EFM was still on it... To me that's part of the character of the car.
I agree, if you go on for fmj bodies only there is lots of info on there. Personally I love these Imperials and hope to get one some day.
Critterese for I know a guy....
glennb49
Active Member
I also have done a swap of carb intake distributor from a 81 Cordoba doner car and it was very straight forward with just the MPG buttons not functioning, Yes there is a block off plate and a standard fuel pump was installed. I currently own a 81 Frank Sinatra with the sun roof , one year only available on Imp! Its like one of 50 Frank Sinatras with a sun roof!! Its still injected but has some runability hikups but goes down the road good. That EGR disconnect sounds promising! Does your parts man find any support plate components available? I need the square unit in the front that melts its goooy inureds and it runs down the intake, that did a lot of cars in! Mine is starting to melt! They actually built a few carbureted 83 Imps in end .
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If you have a part number I will search for it. Our Star Parts system does not go back far enough and microfiche was tossed out years ago
Carmine
Old Man with a Hat
You can even make the MPG calculator work with a carb, you just need the fuel flow meter and re-calibrated dash. I doubt most people would care.
I would take a stab at going through the EFI system. If the infonet had existed when these cars were newer, many more probably would have been saved. ImperialClub.com is another source for info on repair and conversions. If you do convert, I would remove all the EFI stuff carefully because you might find a kook like me who'd want rebuildable cores.
I also know a local guy who isn't on the web and has literally tons of parts for these Imps. PM if you want his contact info.
I would take a stab at going through the EFI system. If the infonet had existed when these cars were newer, many more probably would have been saved. ImperialClub.com is another source for info on repair and conversions. If you do convert, I would remove all the EFI stuff carefully because you might find a kook like me who'd want rebuildable cores.
I also know a local guy who isn't on the web and has literally tons of parts for these Imps. PM if you want his contact info.
glennb49
Active Member
glennb49
Active Member
Yes Carmine I would like this guys phone number to see if he can help me find a good non melting rectangle unit that sits in the front of the support plate. I don't think individual components were available new , you had to replace the entire support plate according to the shop manual. but hopefully he will part one out!
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