94-940turbo fuel injector problem?

bumpbump57 · Post by **bumpbump57** » 02 Mar 2011, 08:30

94'940tubo
I had trouble with the car stalling when I would come to a faster than normal stop. It would start right back up and this stalling trouble was sporatic. Only recently, on a trip to NYC, the car stalled and it was very hard to start back up. The idle was bouncing from 500 to 1000 rpm's when it finally started. Also it would not exceed 2000 rpm's and it was sputtering. I was going 10mph over the triborough bridge when it suddenly started working normally. I almost got to my destination when it went back to nothing over 2000 and 10-20mph. My thoughts are it is the fuel injector relay.(reason being : a volvo mechanic in a troubleshooting effort on another issue I had, disconnected the fuel injector relay while the car was idling) Could this action have stressed the relay? Could it be the fuel pump? Any input would be appreciated....thanks.

Post by **jimmy57** » 02 Mar 2011, 10:42

your 94 has the in-tank feeder fuel pump and the under-car main fuel pump.
I have had several cars that had the hose that connects in-tank pump to its pipe fail or crack and the symptoms would be just like yours. Usually the problem is worse when fuel level gets below 1/2 tank. The main pump can suck the fuel without the in-tank pump as long as the fuel is above the broken connector hose.
Fuel pressure checks while running and driving will usually reveal erratic pressure and the main pump will be whining and growling when air passes are other symptoms.
The fuel sloshing forward and uncovering the broken hose would explain the fast stop issue.
Fuel relay can be easily checked by using a voltmeter probed between green wire (use a pin to stick down in back of connector) of one of the injectors and the battery positive post with engine running. Voltage should be no more than 0.4 V.
The fuel pump relay can be checked by probing between batt positive and fuel pump fuse (I think #11 on that car) using a long wire from battery positive (be careful) to inside car for the connection for Vmeter to batt. Again no more than 0.4 V
The hose in tank and maybe a new pump while the cover/sender/pump unit is out is a good idea. If the car has in excess of 150 K miles then the in-tank pump could be getting near its life end. The in-tank itself could be the cause.

bumpbump57 · Post by **bumpbump57** » 02 Mar 2011, 11:24

Thanks for the advice...I am going to try for the quickest and easiest way first. I am not home and don't have all my tools at hand. Going to replace relay. Thanks again.