850 Starting Problems

95bolvo · Post by **95bolvo** » 16 Feb 2012, 06:09

Following up from yesterday's post....still having problems starting....it did start yesterday evening, still using the starter a little more than usual. Drove it for an hour on the way home, ran fine, parked it in driveway, turned it off and then tried to start, turned over as usual but would not fire. I tried jumping the fuel relay like you suggested but my relay is different than what you described. It has 5 posts 1-15, 1-31a, 1-31b, 1-87a, 1-87b. I jumped the clip between 15 and 87a, 15 and 87b, 15 and 31a, 15 and 31b, nothing worked. Somewhere in all that jumping I blew the fuel pump 15 amp fuse. I repalced the fuse and tried jumping again but only to post 15 to post 87a and 15 to 87b,but she wouldn't hit. Didn't blow the fuse that time, i don't think it liked jumping to the other posts. I then disconnected the wire that leads to the igniton coil mounted on the fender well, just behind the air intake box, set it up there close enough for the spark to jump from one to the other, killed all the lights and turned the starter over but no fire whatsoever. Could it be a failed ignition coil ? Do they go bad or is that a rare problem. The car does have 217K on it and it looks like it could be the original one. I hate to buy one and it not be the problem, I think electrical items are non returnable. How else would you check the spark ? Thanks !

Post by **jblackburn** » 16 Feb 2012, 06:56

If the car runs, the ignition coil is fine.

In this case, you have either a bad cam or crank position sensor. Either can become flaky when the engine gets nice and hot, and intermittent problems are by far the hardest to track down.

I would suggest checking to see if there are any codes stored in the computer first (as in the next time you drive it). Cars may sometimes store codes even if they don't illuminate the check engine light - if they notice something wrong, they'll remember it for a short while, but it takes multiple occurrences of a code to set the light.

Post by **rspi** » 16 Feb 2012, 07:30

The purpose in jumping the fuel relay socket is to see if the fuel pump comes on. Did it? Install jump wire, turn key on, listen for fuel pump.

95bolvo · Post by **95bolvo** » 16 Feb 2012, 10:00

to rspi, I didn't listen specifically for the sound of the fuel pump coming on but i was thinking if it was that relay and the fuel pump did come on it would have started, right ? But it didn't......

to jblackburn, ok, i'll check the codes. are there separate codes for the cam position sensor and the crank position sensor or would they be grouped as one ?

thanks for all the good info !