Engine missing only when warm

[mfuld]

On my way home from getting groceries today, my sho started acting up. I was going along and it seems like the spark would cut out for a second or then come back, like it was missing or something. I coasted most of the way home, and it died a few times while in neutral. When I got it home I tried to pull the codes but the engine wouldn't idle for me to run the test. I tried reving it to keep it alive but it kept dying. I did the 60k not more than 3000 miles ago and replaced my crankshaft sensor, and gapped it, but not the camshaft sensor. I was reading through the forums and alot of people are suggesting the cam sensor as the culprit. I still haven't had a chance to tighten my accessory belts, and even though its probably unrelated, hoping that they're too lose and slipping and somehow not charging my battery, seeing as that would be the easiest fix. That's probably not right, but still worth mentioning.

I haven't had this type of problem with my sho before, and it is my daily driver so I was wondering if someone had any time in the evenings this week or coming weekend to take a look and help me out? And to make it all the more fun, I don't really have any tools with me, they're all back at my parents house in CA. I'd appreciate any advice or places to check first. Thanks.

 

[Kean_SHO]

You sure the grounding strap is nice and secure?

 

[mfuld]

I can go double check but it was on there good when i replaced it after my 60k and its been doing fine since. I also unplugged the maf as well and that didn't seem to make much of a difference. It seemed to run smoother but it still had that miss. I also tried unplugging my CPS. When I got it to start, it ran like crap and I had to keep giving it gas to keep it running.


Also I read something about the crank bolt coming loose, and causing problems. Could this be a problem here? I torqued it to 120 ft lbs when i put it back on. I saw 180 ft lbs in one of the posts. Is that what it was supposed to be? 180??

 

[VADERSHO]

Any way i can help let me know! and here is a bump for you

 

[mfuld]

I'm pretty sure it was my DIS. It would seem with the heat and abundance of potholes out here, one of the wires had worked itself out a little bit. I'll be sure tomorrow when i take it out for a drive, but I appreciate the help.

Curtis, I'm still gonna need to borrow some tools later this week, so expect a phone call. Thanks man.

 

[VADERSHO]

No prob man

 

[mfuld]

Well, It's back, so i think its heat related, its only happening when the car is warmed up to normal temps. It was running fine and then out of nowhere again, it started missing again. Only a little noticiable at first, it got progressively worse until it started stalling again. Could a bad DIS be affected by operating temperature?

 

[SHOmethewayhome]

Well, It's back, so i think its heat related, its only happening when the car is warmed up to normal temps. It was running fine and then out of nowhere again, it started missing again. Only a little noticiable at first, it got progressively worse until it started stalling again. Could a bad DIS be affected by operating temperature?

maybe grounding it with the dielectric grease(term?) that goes between the intake cross tube and the DIS could be as the engine gets up to operating temperature it's causing problems.

 

[mfuld]

I tried taking it off and replacing it with the arctic silver 5 i have left over from my building my computer and that made no difference. But it runs perfectly smooth when its cold. It does fine until it warms up and the needle is in by the 'm' in normal. It'll start as a barely noticeable miss, and then a few more, and then it'll get more pronounced and then it'll stumble. Revving it makes no difference, as if certain cylinders aren't firing. The tach needle will bounce up like its only at 2/3 the actual rpm?

I'm inclined to think its my cam sensor, but hoping its my DIS due to ease of replacement. Any thoughts?

I think i'll pick up a cam sensor from autozone and see if I can get it in there this weekend. Any one up for helpin' out?

 

[mfuld]

So I replaced the DIS and its still happening. :cry: so i think I'm gonna try and replace the cam sensor and seal this weekend if any one wants to lend me a hand.

Any advice on replacing the cam sensor? It looks like I just take off the intake manifold to get some room, take the sensor off, pop the seal out and slap the new one on, right? Any tips? Its just my luck that this is the one thing I didn't change when I did my 120k a month ago.

Thanks guys!