1996 Volvo 850 non turbo

[zupta82]

Hello everyone, it’s kind of been a while since I posted anything. I was recently repairing a rusty section of my catalytic converter along with a new o2 sensor after the cat. I went to go start the vehicle and it will not start it cranks over but not even the slightest bit of running. Here is what I did so far hope it’s not too long of a list

1) checked for spark out of the coil during cranking and there is arcing. I tested the cam and crank sensor. I checked the sensors following the chiton manual, however I did notice that primarily with the cam sensor there was proper 12v and 5v during cranking but when checking for ground to the the neg terminal of the battery I got about 6 meg ohms when it should be close to zero ohms. I tried another used cam sensor that I believed was good and still the same. I looked under the distributor cap and the brass terminals are like new. Then I checked for resistance of the primary and secondary of the ignition coil and it was within specs. I didn’t check the transistor power stage, I did swap it out with another one.

2) Now I checked for fuel pressure at the rail and I’m getting about 40psi with the ignition in the on position. I pulled out the fuel pump control relay and (the small red one), I found some dry solder joints and re soldered them on the circuit board, still no success. I looked at the fuel injection relay(grey one by the radiator and found a corroded small wire almost severed off the connector. I repaired this connection by re soldering and looked inside the relay which had perfect solder joints, I also checked for resistance at the coil and checked the operation of the switch inside the relay by moving it and checking the resistance.

3) Early on I did notice that the battery died rather quickly, I recharged it on a slow charge for 10 hours. It died again within two days. I’m thinking there has got to a bad ground that is probably draining the battery as well. I would greatly appreciate some help.

[scot850]

If the battery is draining then the only real way to do this is to disconnect the -ve battery terminal and connect a circuit tester between the battery and the -ve lead. Make sure the doors are closed and don't open any doors or you will likely fry your tester.

Then see what drain is on the battery. For an 850 I would expect 10-20 mA as normal. Higher than this then something is draining the battery. Then it is a laborious case of pulling each fuse in the fuse box by the hood hinge in front of the drivers seat. Check to see if puling any of the fuses makes the drain drop. If there is an issue then hopefully it will identify the circuit where the problem lays. Then it is a case of checking each electrical component on the circuit by disconnecting in turn.

Issues from my experience and reading on here over the years are:

1) Glove box light not turning off even when the lid is closed. To check, put a cell phone in there running on video setting and close the cover and then check and see if the video shows it turning off.
2) Tailgate/trunk light staying on. Broken wires in the LHR hinge areas on both sedan and wagon are common and can cause shorts.

Note: The standard radios have a slight draw on the battery, hence the normal draw of 10-20mA as it is used to maintain the radio channels and memory.

If you are getting fuel and spark then the car should run.

Poor starting can be caused by a few things like:

1) Tired starter drawing too much current, or poor connections on the wiring to the starter or corroded terminals
2) ECT (coolant temp sensor) failing or connections at the back of the power steering pump with corrosion or rusted connector contacts or even broken wires.
3) High resistance on the battery wires from internal wire corrosion
4) As you mentioned, ground issues. Again checking the ground cable for the battery. Then the others like the back of the block to the bulkhead, there is one to the LHF strut tower, I think there is another at the RHR corner of the engine to the frame, and again one from the engine to the near the RHF inner fender near the hood latch.
5) Have the battery checked for a dead cell. It may read 12V+ but when asked to supply high starting current it can't do it.

There is another issue we call 'lawnmower syndrome'. If an engine has sat for a while and if there has been multiple attempts to start the car fuel washes the bores and loses compression so the engine won't start. Check compressions or add a small amount of oil to each bore to help increase compression and once the engine starts it should be good.

Good Luck!

Neil.

[Galaxion]

Did you resolve the problem with your vehicle? I too feel there may be a problem with the fuel injection relay. I had changed the fuel injection relay and rewired (this is my son's first car) and while the vehicle runs somewhat rich, I'm wondering if I didn't cross the two red wires by accident. Any thoughts on this? TIA, and I hope you resolved your troubles.