Dear beefstew,

Hope you're well. The '95 940, non-turbo, has a single in-tank pump (Volvo Part #9438001, replaced by #9445444).

Prior to 1992, the Bosch-supplied, two-pump fuel system was the norm: a small in-tank pre-pump and a main pump externally-mounted on the floor pan, under the driver's seat. As a result, in-tank pumps from pre-1992 models (240s and 740s) cannot be used in a '95 940. These in-tank pumps simply lack the power to move enough fuel.

Fuel pumps from model 850s might have enough power. However, the fuel pump arrangement is so different from that of the 940s, that the pump might not even fit on a 940 car's fuel tank send unit. The same applies to fuel pumps used in any post-2000 car.

For in-tank pumps, pump dimensions matter: there's not a lot of room to spare, when it comes to removing a 940's fuel send unit (with attached pump) from the tank. I do not recall reading a post over the past few years, in which anyone reported using in a 940 or 960, a fuel pump for a 850 or an S/V 40.

Thus, the range of donor cars is limited to 940s and 960s. Even within this narrow range, great care is needed. Few, who post on this Board, seem to have experimented. Rather, they have replaced the single, in-tank pump on a '95 940 with the exact same part.

Because in-tank fuel pumps are not easy to access, few seem to have wanted to experiment with even a factory-fresh pump, not specified for a '95 940. Even less so would one want to experiment with a pump from a donor car, unless the pump's appearance suggested it was nearly new. A nearly-new pump's plastic fittings will be bright white plastic. A "low miles" pump will be a light light ocher or a pale-to-medium brown. Generally, the darker the deposits on the pump, the older it is.

In 1992, the Rex-Regina fuel/ignition management system - with a single, in-tank pump - was introduced for non-turbo engines. Also, in 1993 and 1994, both non-turbo and turbo-equipped cars also were made with the two-pump Bosch fuel delivery/management system. Thus, in 1993 and 1994, Volvo made 940s for sale in North America, that had a single fuel pump (Rex-Regina; with light blue fuel injector caps) or two fuel pumps (Bosch, with bright yellow fuel injector caps).

A pump from a car with Rex-Regina fuel management system might work in a '95 940. I do not recall a post reporting such an experiment. The likely reason: accessing the in-tank pump is time-consuming. Few would want to have to do this twice, i.e., to install a Rex-Regina pump in a '95 Bosch-equipped car, only to find that it didn't work.

In 1995 - the last year the 940 was sold in North America - non-turbo cars had either the single pump Rex-Regina fuel management system, or the single-pump Bosch fuel management system. I infer from the fact that these pumps have different part numbers - (Bosch, non-turbo, #9438001 replaced by #9445444); (Rex-Regina #3507736) - that these pumps do not interchange. The turbo-equipped '95 940s used a fuel pump with #9438756.

Up to and including 1994, 960s used a two-pump set-up, with the main pump externally mounted, just as it is on a '94 or earlier Bosch-equipped 940. Because this externally-mounted pump supplied a six-cylinder engine, 960s require a more powerful main pump, than do 940s with a two-pump fuel delivery system. Until 1994, the 960's in-tank pump (#3507436) was the same as that used on non-turbo 940s.

In 1995, 960s were first equipped with a single, in-tank pump (#9438756). I do not know if this pump would work in a 95 '940. It likely is over-powered for a 940.

In short, the single in-tank pump used in '95 940s seems to be unique. Therefore, I'd only replace it with the identical part.

All this said, there will be an example or two of exceptions to everything above-stated. Because there 940s and 960s (and likely most other fuel-injected engines) have a fuel pressure regulator, the risk of using a non-specified pump is under-power, rather than over-power. If too little fuel is delivered, the engine won't run properly.

Fuel pushed by an over-powered pump won't be needed, and will be returned to the tank. However, excessive pump pressure could damage/destroy the fuel pressure regulator. This part is easy to access, being atop the engine. But it isn't a low-cost item.

Hope this helps.

Yours faithfully,

Spook