Volvo '97 850R Cranks but won't start - well maintained 170K

Ky Maverick51 · Post by **Ky Maverick51** » 30 Jan 2010, 08:28

1997 Volvo 850R - 170K mi. Won't start. Bought used with 56K, driven weekly to work, maintained per Volvo recommendations. Parked in my gargage, 2 days later, attempted to start, turned over about 2 times, heard a muffled misfire sound and died, still cranks fine, but will not start. Timing belt replaced at 149K, verified timing marks (OK), have spark from the coil wire at the distributor, replaced spark plugs (had 20k mi on them) and rotor, distributor cap in excellent condition, have gas at the fuel line - rail connection. Checked fuses, all ok. Replaced the camshaft position sensor, and the fuel filter. Cranks fine, but will not fire. Just purchased a Crank positon sensor, but not installed it yet. When I turn on the key, I hear the fuel pump prime, so I assume the pump and relay are ok. I'm stumped on this one.

Post by **Pauloil** » 30 Jan 2010, 08:59

I was trying to find what can go wrong on sensor replacement, and Ozark lee stated:
Make sure the key on the position sensor is set into the slot on the end of the camshaft before you torque it back down.

it is also impt to get the plate over the seal in proper orientation
sorry, but I couldn't find the post, but there is a lot posted on getting the sensor positioned properly on replacement.

Post by **jblackburn** » 30 Jan 2010, 09:46

If the cam position sensor isn't working the way you have it installed, flip it around 180 degrees.

You can also test the leads on the crankshaft sensor for continuity. If you're getting between 0-100 ohms, it's dead.

It sounds like you've taken care of everything else and that the problem is just getting spark to the plugs, which either of the sensors would cause.

Ricky_devon · Post by **Ricky_devon** » 30 Jan 2010, 10:13

Hi,

I had a 940 B200F which pulled exactly the same stunt! Your symptoms are identical as mine was. Since you've already purchased the crank shaft sensor - then fit it. That was the cause of the problem on my 940, a simple job on the inline B200, haven't done one on the 850 so I can't help with that I'm afraid. Without the crank shaft sensor working correctly (or not at all), it sends the ecu into chaos, then randomly fires ignition pulses & fuel, or doesn't activate the fuel injectors at all. Also note, that on the 940, it never triggered the management/lambda light either.

Ricky.

Ky Maverick51 · Post by **Ky Maverick51** » 30 Jan 2010, 11:12

Ok, Guys, thanks for the feedback. I will retrace my steps on the Camshaft sensor, and install the crankshaft position sensor while I'm at it. I'll log back on in a couple of hours. It's about 22 degrees here and my garage isn't heated, ..just a small electric heater. thanks again.

Ky Maverick51 · Post by **Ky Maverick51** » 30 Jan 2010, 14:17

Well, no joy. Checked the Camshaft Sensor and it is correct, installed the crank sensor, and I still can't get spark to the engine. Although I checked for spark at the coil a couple of days ago, and it was there, I do not have it now, started with the #1 plug, then distributor coil wire and then at the coil. No spark. I verified all connections are good, but the coil won't energize. Is there a Relay somewhere that does this?

Thanks

Post by **Ozark Lee** » 30 Jan 2010, 22:51

The tell here is that it started briefly and hasn't started since.

Fully charge the battery, get the car out of the garage, dump a teaspoon of oil into each cylinder through the spark plug holes and then replace the spark plugs.

Floor the throttle and lay on the key until it well and truly fires up and runs - it may try to start and then die again - keep on the starter until it can sustain itself.

The smoke cloud will be amazing for the first few minutes but after that it will likely be just fine.

EDIT: I missed the part where you pulled a plug and have no spark. Was the spark plug wet? Deal with the ignition issues first.

...Lee

Post by **jblackburn** » 30 Jan 2010, 23:59

Although I checked for spark at the coil a couple of days ago, and it was there, I do not have it now, started with the #1 plug, then distributor coil wire and then at the coil. No spark. I verified all connections are good, but the coil won't energize.

Nope, no relay. If the plugs still aren't sparking...those 2 sensors, the ECU, and the ignition coil together control that. Maybe you have a bad brand-new camshaft sensor? It's happened before...again, the continuity test between leads would confirm or deny this.

polska · Post by **polska** » 02 Feb 2010, 22:25

If your battery is good, did you check the coil for resistance?
I couldn't find the specs in the Haynes manual - anybody have those?

I would think a bad crank sensor would set a code.

Post by **boosted5cyl** » 03 Feb 2010, 06:34

Take this for what its worth, but other motors ive worked with will fire without a cam sensor. It will throw a code of course, but it should run. If the crank position sensor isnt working however, you'll get zilch. Does the tachometer move when you crank it?

Am I right in saying you are not getting juice INTO the HT coil? Basically you need to trace the whole ignition system back from the plugs.

No spark but you have a HT voltage from the coil? Its probably the the distributor or the HT lead connecting it to the HT coil.
Distributor and HT leads OK? Check for presence of HT voltage at coil. (Careful now!!)
No HT voltage? Check coil resistance.
Coil resistance OK? Make sure the coil getting juice on the input (low voltage) side.
No getting juice to the coil? Check fuse and make sure there is juice at the fuse socket too.

HTH, maybe someone else can fill in my blanks with regard the ECU and soforth.