I have a 95 960 that stalls when it gets hot or normal operating temp. It feels like its out of gas but tank is full. i sometimes smell gas. It wont start again until its cool, then stall out when at temp. I ran the codes and one was a coolant temp sensor, so i replaced it and same problem. I erased the codes and the coolant temp sensor came right back on. could this have anything to do with it? also the code for fuel trim came up, wasnt even sure where to start with that one. Any help would be appreciated

 

What are the codes, how many miles? How warm is it where you are at?

I think the fuel trim code will be the most important, they are just clues afterall, you may not have needed the temp sensor.

Most likely it is resistance at a connector, very common thing with volvos weather resistant electrical connectors.

DanR '94 964 385,000 miles (151,000 on the new engine)

 

I erased the codes so not exactly sure what they were, one was fuel trim and the other was ect. I did check resistance at the connector for the temp sensor and is goes from 0- 17 when its wiggled, so im thinking its a bad connection.

 

Try reading for codes again, there are some that will not trip the check engine light.

DanR

 

I replaced the coolant temp sensor and connector, thermostat, plugs, and MAF, still stalling when hot....I am at a loss now and feel defeated with this thing

 

Do you have any codes? How does it stall? Does it idle, if so how is that idle? You could have an air leak, a bad idle valve, a bad throttle position sensor. YOu are just replacing parts, without knowing why it is idling badly. You need to describe the symptoms in more detail, retrieve codes, or wait until they reappear. Codes are just clues, but usually for my vehicle, connector oxidation is the number one culprit for runability issues.

DanR

 

The second the radiator fan goes on it will idle differently, almost like a misfire. the only code that came back on is the coolant temp sensor. also if i start it when the maf sensor is disconnected then it wont stall, it will also restart, but it restarts hard. i did replace the maf too so now im just going nuts...any other ideas? thank you

 

One thing to check, though I still believe you are getting unmeasured air into the intake side.

There is a foil hose that goes from the air filter box to the exhaust side of the engine. Remove the air filter and check the door flap at the bottom of the housing, the temperature sensitive valve can seize up and keep the door to continually pulling hot air from the exhaust side. That valve is only for the first few minutes of a cold start and then it switches over to pulling cooler air from behind the grille. If the valve gets stuck then it only draws hot air into the intake manifold.

The engine codes are nice to have but because you get a temp sensor code, does not necessarily mean that it is the temp sensor. It is just a clue to the final answer. I one could get a hold of the Volvo scan tool or the breaker box attachment, one could see in real time all of the engine functions, but the code reader on the fender is all most have access to, which makes it just a clue.

It also sounds like maybe you have some grounding issues or a coolant fan that is pulling heavy amperage. Look at you electrical connections, especially the grounding, the batter terminals, also the battery cable themselves. Sometime they can oxidize internally and you might have to peel back the insulation on the negative cable.

Check the connector at the fan relay, right in front of the battery, check for oxidation.

DanR

 

Have an ohm resistor handy and when it stalls, check the resistance of your crankshaft (rpm) sensor. It should be above 200ohms... if it is below, Id put my money on it being the problem.
The connection is at the back of the motor (at the top) on a bracket where a few wires connect up. Its the one that has a wire going down to the connection between the motor and transmission. Very visible if you stand next to the passenger wheel and look in between. Follow the wire up to the bracket... Disconnect the wire and have your two test leads touch the two pins. Make sure you are testing the lead that goes to the sensor...