Trying to start the project car

[scoobydrvr]

I purchased this car for a little more than a song; previous owner couldn't get it to run, ran out of time/interest. I've finally been able to replace the poorly repaired wiring harness and the fuel lines he bent up trying to get the intake manifold off. Tried to start the car and it's a no go. It cranks, sometimes coughs, but does little more. My dad has been helping me out and his past as a Subaru Master Mechanic has been really helpful but he's having trouble remembering details about this car ("They just didn't come in that often so I hardly worked on them"). He did offer up one clue as to what may be going on: when the ignition is in the run mode, the fans fire up. He says this is an indication the car thinks it is really hot and as such it won't provide enough fuel to start it. First thing I need to check is the temp sensor with two wires.
This is where I'm hoping I can get some help: I don't know what the proper resistance of this sensor is or what kind of voltages I can expect on the harness side of the plug. The resistance of the sensor is 2.057 kOhm and I'm getting 4.9V on one pin of the plug and 9.7 on the other pin (I suspect there might be an issue with this plug as it and the sensor for the gauge have had the wiring replaced with something akin to speaker wire ). Can anyone offer me some insight as to what I should be reading on these?

[Wikedjuggalo]

Originally Posted by scoobydrvr

I purchased this car for a little more than a song; previous owner couldn't get it to run, ran out of time/interest. I've finally been able to replace the poorly repaired wiring harness and the fuel lines he bent up trying to get the intake manifold off. Tried to start the car and it's a no go. It cranks, sometimes coughs, but does little more. My dad has been helping me out and his past as a Subaru Master Mechanic has been really helpful but he's having trouble remembering details about this car ("They just didn't come in that often so I hardly worked on them"). He did offer up one clue as to what may be going on: when the ignition is in the run mode, the fans fire up. He says this is an indication the car thinks it is really hot and as such it won't provide enough fuel to start it. First thing I need to check is the temp sensor with two wires.
This is where I'm hoping I can get some help: I don't know what the proper resistance of this sensor is or what kind of voltages I can expect on the harness side of the plug. The resistance of the sensor is 2.057 kOhm and I'm getting 4.9V on one pin of the plug and 9.7 on the other pin (I suspect there might be an issue with this plug as it and the sensor for the gauge have had the wiring replaced with something akin to speaker wire ). Can anyone offer me some insight as to what I should be reading on these?

Silly question... have you checked for engine codes?

[1986nate]

The sensor is $25 from Subaru, just get a new one. This sounds like typical symptoms of it failing.

Try holding the throttle open as you crank. It sometimes will help get it going when it's failed/failing and has worked to get me by for a bit when they've failed.

[scoobydrvr]

Originally Posted by Wikedjuggalo

Silly question... have you checked for engine codes?

No, didn't check ECU codes; I didn't have my scan tool handy and it was getting late when we were trying. I'll hook up to it tonight and see what the car thinks the engine temp is.

Thanks for the quick replies all. I'll call the dealer in town and see if they have one of these sensors handy.

Can someone verify the voltages I should be seeing on the two pins for this plug? As I said before, someone has hacked together the wiring harness for this sensor and the temp gauge sending unit and I would like to know for sure if the harness is in good shape or not.

EDIT: Voltages with the plug disconnected and the ignition in the run position.

[scoobydrvr]

Found the problem: seems the car has had some rodent damage in the past. The "upper" engine harness had been hacked together by someone which I replaced from our donor car. I noticed while I had the intake manifold off that there were a couple sensors that had been rewired on the "lower" harness but hoped that it was in operating condition. Turns out that there were some shoddy connections made with butt joints that caused the car to think it was -40 degrees (Fahrenheit or Celsius, take your pick). I replaced that harness from our donor car and all seems to be well now. Going to put it back together tonight and see if it will start. Fingers crossed!

[Wikedjuggalo]

Since you have the intake off already go ahead and replace all the vacuum hoses. After 20 years they tend to get brittle. Might as well replace the PCV as well. The valve is less than 10 dollars IIRC. Worth doing to avoid breaking a brittle hose then breaking a solenoid then curing your svx for a month.

[scoobydrvr]

Originally Posted by Wikedjuggalo

Since you have the intake off already go ahead and replace all the vacuum hoses. After 20 years they tend to get brittle. Might as well replace the PCV as well. The valve is less than 10 dollars IIRC. Worth doing to avoid breaking a brittle hose then breaking a solenoid then curing your svx for a month.

I'll be doing that when we pull the motor in the near future. The plan is to just get it running and see if it needs anything mechanical then pull the motor and do a complete reseal on it. I had planned on replacing all of the rubber hoses. A few of them have already split when I was working on it.

Forgive my ignorance, but is the PCV the square-ish thing with hose connections on either side?

[davew833]

Nope... PCV valve screws into the center of the underside of the intake manifold.