Hey guys,

I have a 96 850 non-turbo, manual transmission, 164,000 miles. The problem is that it won't start. It will crank but will not run. After doing much searching on this site I have done the following:

Checked fuel pressure, its good.
It has spark.

So it has air, fuel, and spark. Here is the weird thing, if Iremove the fuel pump fuse the engine will crank for a few second and then start running (only runs for another few seconds till the fuel runs out). Put the fuse back in and it cranks but will not fire. Looks like its flooding as the plugs are soaking wet when I pull them out.

After looking on this site a few posibilities for non starting are: cam sensor or the coolant sensor. I don't think its the cam sensor because it will run once the fuel pump fuse is pulled. I'll test the coolant sensor tomorrow. Also, I checked the ignition coil and the primaryreads 7.6 ohms (should be between .5 - 1.5 ohms). Could the coilbe the cause ( remember Ido have spark)?

Any suggestions are welcome.

 

I would check the coolant sensor as you said, and also clean and dry the plugs, or replace them entirely. One trick that sometimes works is to floor the gas pedal and crank the car. You may have to crank it for almost a minute (so make sure you have a good battery) but others have tried this and gotten the car to start and then run normally.

Good luck

 

Check the fuel pressure regulator. When they fail they often dump raw fuel into the intake manifold.

...Lee

 

Had to replace the coolant sensor (ohm reading was all over the place). Put the new sensor in and went to start it, this time I can hear it trying to catch but it just won't fire up.

I then took off the cam sensor and messed around with it, cleaned the inside. After I put the cam sensor back in I went to crank it (had to keep the pedal floored). Well, the car started. Had to keep the rpms above 3k but it ran, for about 30 seconds. Try it again and the thing runs for about 30 seconds then starts dying and backfires.

I think I'll try to find another cam sensor seeing as the car started right after I messed around with it.

Any other suggestions? Maybe the timing is messed up?

 

Damn it, did a compression test and got 90, 150, 0, 165, 70. Will a bad headgasket cause 0 compression? I don't think so, probably bent valves. Which means timing is screwed up. So, I guess I will tear the SOB apart, get a used head, new gasket, timing belt, and water pump.

 

I would pull it and inspect it the valve might be burn't instead of bent.

 

Ouch.....Let us know what you find

 

Is burnt valves a thing with 850's tech? I had one on the #1 cylinder a few weeks ago.

 

It is more with the 960's which are N/A 6 cylinder versions of the same motor. But I have seen quite a few 850's with them burnt as well.

 

caused by running lean I assume.......

 

Well some will say that. What we have realized is that since the gas prices went up alot of people were not using Preminum gas and only using Regular gas and thats when we started to see all the burnt valves. So it is either from using Regular gas or something they put in the gas.

 

gotcha! a little pre-ignition or detonation maybe. as long as fuel prices are down,I'll berunning premium, especially with higher boost.......

 

I hear you I try to run it all the time as well. If I have a tank of the lower after I try to run fuel injection cleaner after.

 

Well, it has been a long time since I lasted posted and I like to finish up my threads. So I finally got down to tearing apart the volvo.

Here is what I found. Talk about bad luck.



So, bent valves in #3. Now, can someone tell me what is going on in #1? It looks like something was bouncing around in the cylinder and chewed up the piston and the head. All the cylinders have these marks, though not as severe as #1. Anyway, it looks like I'll be looking at another engine.