My 1994 Volvo 940 Wagon has an issue that I can't seem to resolve.

It began with an intermittent issue where the check engine light would come on and the vehicle would suddenly start missing and losing power. If I pulled over and turned it off then back on I would be back on the road for a while with no more problems. I changed the fuel filter which seemed to stop the problem for several days then it returned.

Later the problem became more frequent and finally I had no power at all and the car ran rough. The car would only run for 2-5 seconds then stop. I cleaned the idle control valve, throttle body, some vacuum lines, etc... After doing the self test procedure on mode 3 of the Module #2 fuel system diagnostics I was under the impression that fuel injector #1 was not vibrating/ operating correctly. I tried putting wire number 1 on injector 2 and I could feel it operating I believed sop I decided to try replacing injector #1. The results were no significant difference. Now it appears to run for 10-20 seconds then dies but won't keep running. My friend says if it was an injector it would have run much rougher... I'm not so sure but he suspects the fuel pump. I was considering removing it hoping it was the cheaper one, but after following the fuel lines I am pretty sure their is only 1 fuel pump - the one in the tank. I unscrewed the lid and detached fuel line and put a dry rag under it and could see that it had pumped out some fuel to pressure line. I can feel fuel pump relay click when I turn on the ignition and turn off shortly afterwards. I'm not really sure where to go from here as I don't want to replace an expensive pump and not solve the problem.

Update: I just spoke to the previous owner who informed me he replaced the fuel pump 2 years ago. The car has run out of gas a handful of times since then so possibly could have sucked up sediment and be clogged perhaps?

Suggestions anyone?

 

The pump's fine.
What was the OBD code exactly?
If it was injector, you can't just swap the wires, and yes, one injector can make the car run quite poorly as the computer compensates and enriches the system.

 

regina systems use only a single in-tank pump, which is a different in-tank pump than that used with the 2-pump Bosch systems (and yes, there are 1 pump Bosch systems too, just to really confuse the issue).

 

oh. the proper test for a fuel pump is to hook up a fuel pressure gauge to the fuel line into the injector rail, and run the engine. I believe 42-44PSI is the correct number for Regina (I know its the right number for Bosch LH systems). if there's a vacuum line connected to the pressure regulator, you plug this into a T that also goes to the pressure gauge, as those systems, its 42-44 PSI relative to manifold vacuum (bosch does this, I dunno regina).

 

At this point the only code I'm getting is a 2-2-1. The original codes I got (when I discovered the code generator) were both Lambda codes suggestion I check vacuum to intake manifold I believe. As for the injectors I switched wires to see if the wire may have been bad but it seemed to make injector 2 vibrate... The injectors are Siemens I believe - for all I know the original ones

 

I don't have a fuel pressure gage at the moment unfortunately... But this afternoon I replaced the check valve coming out of the master cylander or whatever its called and had the bottom hose disconnected to the idle control valve (as I intended to replace it as well). The car started and i was able to keep it going for a while around 3000 rpms although i could feel it wanting to wane. I then remembered the hose was disconnected and turned off car. The hose was almost flushly covering opening... When i hooked it back up it would not run. Disconnected again would not run... Baffled again

 

Code 221 is Oxygen sensor not operating, caused by Oxygen sensor or intake air leak.

 

Thanks Lev, I'm double-checking all my vacuum lines but probably am going to have to replace that sensor... $140 part locally... will a Universal Oxygen sensor work? they seem to range from $25-$80 online...

 

a Bosch generic 3-wire narrowband sensor will work, but you'll need to splice it onto the wiring harness that is on your existing Volvo OxS... the correct Volvo ones plug in (2 connectors, a single pin for the heater and a double pin for the differential signal)

 

Regina cars have different O2 sensors than Bosch.

 

Which color wire is for the signal and which two wires colors would go to the heater circuit of the bosch universal 3-wire replacement. Original wires are red, black, and white

 

I need to retract that statement I made about generic bosch O sensors, as I neglected to notice this thread was about a Regina system. as someone else said, regina EFI requires regina ox sensors. There's probably some generic mopar replacement part, but I dunno what it is.

 

Fuel pressure was well below that... maybe just 10 lbs I believe... fuel pump was pulled and seems to be running a little rough without much pressure.

Also I've had along term fuel guage malfunction that I seem to recall possibly having to do with ground to fuel pump? Any suggestions while I have it apart?

 

The one I bought was a Bosch unit (13193 I think), 3-wires... I figured it out. Black was sensor... 2 white wires were heater circuit which corresponded to the white and red wires indifferent to polarity I was told. Result: No significant difference...

 

if you end up getting another fuel sender unit, CHECK ITS WIRING BEFORE INSTALLING. been a lot of reports of NEW fuel senders with incorrect wiring.

with the fuel sender out of the tank, you should be able to hook it up to the wiring, and turn the key on, and manually move the fuel float, and watch the needle move correspondingly (albeit slowly).