Hello, im a new member and having issues with fuel, i have replaced pump in tank due to not operating at all, this solved my problem but for only a month or so then problem reoccured. I figured bad pump again so had pump warrantied part changed out and once again engine ran properly, now after only a few miles i have low power. Engine running rough,sometimes engine will die at idle. I can still hear pump at key on position, but only have 9 psi at rail. I have been told their are two pumps on system, but i have looked and not located the 2nd pump. Where would it be located? I have traced lines but not found anything that resembles a pump. Any ideas out there?
Thanks

 

the other pump is on the underside of the car, approximately under the rear seat, its paired with the fuel filter, and protected by a metal basket/shield. that 'other' pump is in fact the MAIN fuel pump, which develops the 42-44 PSI your fuel injection system requires. the pump thats in the tank is a low pressure pump, its purpose is to help the main pump get gas, and prevent vapor lock, especially when the gas tank is low.

 

I did not find a second fuel pump outside the tank, only filter where the basket was located.

 

Someone has some 'splainin to do.

 

does this car have Regina injection ? they only used a single main pump, which has to be a special Regina pump NOT a regular Bosch one.

 

RGuy here. I have found the fuel regulator to go bad more often than the fuel pumps.The car will run with one pump.The main fuel pump is under the drivers sear outside of the car. The one in the trunk is the slave pump. It will run with just the main pump working but will shorten it's life. The fuel regulator on the other hand is at the front of the fuel rail. Cheap part and worth putting a new one on just for giggles!

 

we need to ascertain if this car is REGINA or BOSCH injection before we give any more advice. a Regina car does not have an MAF, instead it has a manifold air pressure sensor (MAP), and instead of a conventional 'beer can' coil with a seperate ignition power module, it has a square coil that looks like a transformer, which has an integrated power module

Regina cars have the main pump in the gas tank, not under the car. if you installed a bosch in-tank pump on a regina car, you would have very low fuel pressure.

 

Sorry for taking so long to reply. The best I can tell this car has regina system[square coil]. I have pulled vac. line frome fuel regulator and no fuel present also reg. will hold a vac. I deadheaded fuel line before rail with pressure guage and once again only had 9 psi I think it should read max fuel pressure this way. Like I said yesterday I have changed pump twice now and car ran fine for a little while. Is it possible parts store is selling me like you said Bosh pump and this is my problem?

 

yeah, 9PSI sounds about like what a bosch intank pump might develop as its purpose is strictly to deliver fuel to the bosch main pump under the car.

for regina systems, Ive heard you can use the bosch in-tank pumps from LATER Volvos, like 850's, S/V70's, etc. these also are single-pump systems and run with the same 42-44 PSI regulated pressure, so the pump will likely develop at least 50PSI static pressure (which the pressure regulator relieves to maintain the 42-44PSI).

 

Have you changed the fuel filter?

 

Yes the first thing I did was change the filter. Im just curious to why after changing pump the first two times the car ran fine for a little while then started running badly again . Seems like if wrong pump was installed and only developed 9 psi it would have never ran properly.

 

Ok ordering parts frome volvo today. I think like you guys that my local part store has caused me problims. I will try to get pump changed this weekend and will let you know how it goes. Thanks so mutch for info. You have really been a great help.