[Natasha Cramer]

I'm potentially doing some work on a crank-no-start 2.2L Reliant that isn't getting fuel to the carb. I'm told it also had starting problems on hot summer days, which my research tells me is related to the mechanical fuel pump. So I figured I'd kill two birds simultaneously by replacing the inline filter(s) and converting the pump to electric. However, I've scoured the internet trying to find instructions or parts related to the common procedure (so I'm told) of converting the mechanical fuel pump to electric,but I've found nothing. One friend said he had in the past attached a low pressure pump in a housing to the frame and then wired it up. It seems like there should be more to it, and what are my options if I want to use an in-tank pump: do I have to replace the tank?

 

[Bob Lincoln]

Much easier to replace the mechanical pump with another rather than convert. You would need a relay, fuse, wiring, new tank, return line. And it doesn't seem you've proven that it's at fault. There could be a clog, a bad filter. Also, hot start trouble has many causes that may have nothing to do with the fuel system. I'd do more diagnostics first and then look at replacing the OEM pump with another one if called for.

 

[valiant67]

Chrysler did have a vapor lock kit for cars with the mechanical fuel pump. In those cases the cars were fine cold but stalled when the fuel got hot, vaporized and could not be pumped by the mechanical pump. It involved adding a low pressure electronic pump near the tank. However, when I had cars that didn't pump gas as expected with a mechanical pump it was either the faulty pump or a pinhole in the lines between the pump and the tank that caused the problem.

 

[Natasha Cramer]

I thought I'd get an e-mail when someone replied, sorry I didn't follow up sooner. Bob, I'll make sure to test the pump before doing the work, I just wanted to feel out the most thorough scenario so it's not stuck in my garage while I search for information. One more question, valiant67, how much time does that pump conversion take?

 

[valiant67]

I don't know for certain as I don't have a copy of the TSB but I was told it is a 1.7 hour repair time because I'd assume the modification must include some sort of shut-down provision so the pump doesn't keep pumping fuel when the car isn't running. This was an external in-line low pressure fuel pump mounted near the tank.

 

[BlackSheep01]

On an 89 Ramcharger, we had the best of both worlds, IMO. The fuel pump was electric, mounted on the frame rail forward of the tank on the passenger side.
You could hear the electric pump when the key came on, and when it needed service, you didn't have to drop the fuel tank. It was easier to fix that than the
oil pressure gauge sending unit, for sure ...

 

[ImperialCrown]

Early production 1985 Dodge and Plymouth K-cars still had the carbureted 2.2L engine and changed to EFI later on in the 1985 production run. The Chryslers had all changed to EFI in 1984.
There was an external electric fuel pump conversion TSB for carbureted cars that had vapor lock problems and I did a bunch during the warm summer months for cars that sagged or stalled. The underhood heat made the fuel boil out at low pressures and the higher pressure of the electric fuel pumps helped out considerably.
It was more of a 1980's fuel quality problem than a Chrysler problem, but it became a Chrysler problem. We couldn't have angry customers.
The parts for this conversion are probably long gone by now. I may have a copy of the actual TSB somewhere.
You might want to add an external electric pump in series before the mechanical pump to assist in keeping the fuel line pressurized. Or install a cover plate over where the mechanical pump went and just run the electric fuel pump.
An experienced mechanic should be able to add an ASD/fuel pump relay, wiring, pump, fuel pressure regulator and the fuel lines necessary for a successful conversion, but that sounds expensive. I don't recall how they did an ASD relay on a carbureted car.
It may be a lot more expensive than just replacing the old mechanical fuel pump with a new mechanical fuel pump and with today's gasoline it may start OK for you when warm.
Is the car worth sinking a few hundred dollars into? Are the fuel lines and tank badly rusted at all?

 

[John Wood]

Some of the later 80's carburetted 2.2's had a mechanical pump and a vapor seperator. We had one on an 87 2.2 L body. I've also seen them on Caravans and Voyagers equipped with 2.2's in 1987.

I had an old V8 with an electric fuel pump mod on a carbed setup. It was regulated at about 5-6 PSI and was wired to the coil + terminal. The regulator was simply a pressure switch. The moment the needle valve opened in the carb, the pump kicked on unti it reached 6 PSI. Then it shut off until the regulator saw about 4 PSI. Then it kicked back on. It was a very simple operation, but could only be used with a carb setup.