I'm preparing to replace my existing injectors with a freshly cleaned set (junkyard ones I've sent off to Witchhunter) as part of a major tune-up. Figured the FPR would be a good thing to replace at the same time, so I ordered one from FCP.

Now, my car is a Regina, but going back through archives here shows numerous discussions about how it's fine to use the Bosch FPR on a Regina car. So I figured I'd save 50 bucks, and got the Bosch one (sold for both NA and Turbo cars). Now, this is where things get strange. I have a FPR from a junkyard 1989 745 Regina, and it's much smaller than what's on my car (literally half the diameter). THe FPR on the car is the same size as the new 3 bar one from FCP. Now, I was under the impression that the Turbos run 3 bar, the NA cars run 2.5 bar. Of course, the one on the car has no part number or rating visible, just a big Volvo sticker.

I'm tempted to just put the new one on and see how it does, but I'm concerned the higher pressure will make the car run richer, and as I'm having a new o2 sensor put on next week while the car is in for state inspection, I'd rather not ruin the new sensor by running too rich a mixture. Of course, if I've been driving around with a 3 bar FPR the whole time I've owned the car, perhaps this explains why my fuel economy is sub-par.

So, do I install the new 3 bar one from FCP, or do I return that one and buy the Regina-specific one, or do I return that one and buy the 2.5 bar one for 1980's Bosch NA cars?

Anybody have any experience with this problem? This is the first time I've ever done anything to the fuel system of a car, so I'm pretty nervous about screwing around with it.

thanks,
John