96 850 NA misfires, hard start, stalls

[sleddriver]

Look more carefully, compare where the shiny part is on each contact. It's fine, they are all the same! None are ackwards.

I did. Doesn't make sense it should be rotated 180° like that. There's a reason the large flat area faces towards the middle terminal.

[abscate]

I think it is just an illusion in the picture.

[erikv11]

Sorry, my post was obviously not clear: what abscate said. The pic is fooling you, nothing is rotated. The "large flat area" is the shiny part, it points to the middle on that contact, as on all of them.

[eriscentro]

New cap and rotor installed. The car started and ran normally before changing the parts, and it continued to do so with the new parts as well. I drove it around for a few miles, and all seems well. Fingers crossed that was the issue. Attached are some pics of the the old cap and rotor. Clearly they were due for replacement.

[Jaguar xjs]

Gnarly looking cap and rotor. I'm surprised it ran at all. Dont remember reading but did you replace wires and plugs also?

Gordon

[eriscentro]

I didn't replace the wires, since I believe they're from 2011-12 (and should have less than 60K on them). I'm hesitant to replace the plugs because as I noted earlier, the car is my only means of transportation at the moment, and I'm short on tools. If I overtighten, crossthread, or otherwise break something, it'll be a big problem. The cap and rotor are pretty much screw-up proof

Edit: Also, the issues I was facing were random misfires on all cylinders, so all the plugs would've had to go at the same time, and that doesn't appear to be the case.

[erikv11]

I would expect those wires to be totally fine, yep. Nice fix, thanks for posting up the solution.

[rspi]

Plugs should be replaced every 30,000 miles. If you are having misfire issues, that's the first thing that should be checked.

Good that you have Volvo wires, they looked grey in the pic on my temp phone. The date pattern is week/year so your wires are more than 10 years old. They are probably still good but you really should check the plugs. I see original wires about 1/2 the time. My limit is 10 years, 100,000 miles.

I always use Volvo plugs as well. For NA cars, they cost about $25. Usually cheaper than what I see other people pay at local parts stores for different style plugs.

[sleddriver]

If I overtighten, crossthread, or otherwise break something, it'll be a big problem. The cap and rotor are pretty much screw-up proof.

Plugs are easy. Check your manual. I use Bosch copper core plugs. NGK also makes a great plug. Verify the gap. Pull the plug wires off. Blow out the cavities with air. Remove plugs using an extension. Get some anti-sieze compound and apply just a bit, no more, to each plug. Reinstall plugs on extension using your hands without the wrench to ensure they are threading properly. Then torque to spec or just tighten snug by hand, but no more. No worries.....

[erikv11]

... The date pattern is week/year so your wires are more than 10 years old. They are probably still good but you really should check the plugs. I see original wires about 1/2 the time. My limit is 10 years, 100,000 miles. ...

Thanks Robert for pointing this out, my mistake about the date code these wires are a lot older than I thought. But like rspi says, still they should be ok.