Hey Guys,

OK, been chasing this off and on for a couple of months, had a posting or 2 out there. I've checked/replaced the following:

fuel pressure regulator, MAP sensor, crank sensor, set TB and checked TPS (seems good via continuity check), plugs are good, not fouled or super lean. Runs well once past stumble, but sometimes I feel a stumble.

Back to fuel pressure, its seemed OK a month or 2 back, but today:

Jumping the fuses in the fuse box, pressure reads ~28 psi (no good, right, need 33 psi).

Running engine at idle, I get 32 - 34 psi, but it fluctates a bit, not steady, never higher than 34 psi. Quickly opening throttle drops pressure to below 30 psi, maybe as low as 25 psi. Removing vac line from FPR does not cause pressure to increase (looking for 45 psi). I'm thinking its fuel pump time, you guys agree?

I have a spare pump/sender assembly, so I can get a new pump and solder on, but changing is a PIA. I think it's documented on BB somewhere.

Thanks for reading this long post.

Mike

I would remove the hose before the FPR and put in an adapter to find out what the fuel pressure is before the regulator. If the pressure is less than 45 psi, then I would assume a bad fuel pump, filter or obstruction in the line. If it is greater than 45 psi, the regulator is bad

You don't say how many miles you have on the car, but if you are on the original pump, it's probably due to fail by now. It seems that most Regina owners report failed fuel pumps between 150,000 and 175,000 miles. That what I experienced with our 90 740.

Hat's off for actually doing some diagnostics before throwing a bunch of new parts at it - ie. jabbing the throttle, and the resultant drop in manifold vacuum, should increase the fuel pressure, not decrease.

Art Bernstein did a wonderful write-up on fuel pump replacement, complete with a ton of photos. I believe it's been added to the 700/900 FAQ's.

Chris,

It's the 2nd pump, 1st replaced at about the 10 year point. There is only about 70 kmiles on it, but it's been 10 years. Thinking I'll change the fuel filter, cheap/easy insurance, then if no change, I'll start studying Art's write up. I changed the darn thing 10 years back with a buddy, it took a while to figure it out. Thanks.

Mike

it could be sub par filter but there are usually pretty forgiving.
i presume you have verified you do not have any tiny fuel leaks to the engine.

i think its time to have a look at the fuel pump assembly. it is possible there is a tiny leak in the tank hose exiting the pump thereby effecting pressure.

Yeah, I've looked for leaks and have not found any. Fuel filter, though a few years old, has exactly 30,000 miles on it. Never had a problem with these, though I guess I could change it out to be sure. Thanks for the input. Mike