Miss when engine gets warm

[Kean_SHO]

I have an issue that is getting the best of me cause i can't find the issue.
when the engine gets warm it seems like it has a miss. almost like a cylinder is not firing, but i am not sure about that. I just know it has no power and sounds very strange.
I have a CF cowl hood that keeps the engine very cool. on the freeway at 70 MPH the car stays below the first line that marks the NORMAL range and above the blue line on the temp gauge. During this time there are no issues at all. the sho is peppy and sounds fine.
However if i hit traffic and the car starts to get into the middle normal range it will start the crappiness.
I ran the codes got only a VSS and PSP problem code, but already knew i had those issues.
the cylinder balance test came back 9- all fine.
I have not noticed any odd smoke out the exhaust or unexplainable fluid loss. gas milage is consistantly 25-26mpg. I don't see any puddles of fluids when its running or when i leave a parking spot.
I am about to change plug wires (have 5 month old taylor 8mm on now) and inspect the plugs.
anyone have any suggestions of possible issues or tests i can run?

 

[INDO SHO]

I had the same problem on warm up. After replacing plugs and wires it stopped. This could be a long shot but check and make shure the fuel rail chassie is properly torqed down. Is there any pinging or knocking when warmed up?

 

[Kean_SHO]

more details on the "mis-fire"

I had the same problem on warm up. After replacing plugs and wires it stopped. This could be a long shot but check and make shure the fuel rail chassie is properly torqed down. Is there any pinging or knocking when warmed up?

no there is no knock when it gets warm.

here is some more details to the problem
The night this started it was raining pretty heavily. I got the car home and replaced plugs and wires, MAF, the little sensor in the airbox (can't remember the name atm), and the airfilter (it was damp and dirty). The problem wasn't solved but the issue was less frequent. After a couple days i started the car and it ran perfect. I thought the problem was resolved until last night. It was raining again. The car ran fine for the first 40 min... then it felt like half the motor cut out. for the rest of the trip it was in and out until i got off the freeway. For the rest of the drive, about 3 miles of city driving, it ran perfect.
This morning the sho ran fine until i got on the freeway and it was completely out the whole trip. "out" referring to feeling like it was a v-3.

I am now looking at the problem as possibly electrical. Could there be a sensor that is getting wet and not functioning?
So my trivia question is this: Is there a sensor that could fail and- 1. cause a no fire condition to one or more cylinders and 2. not store a problem code?
Could I have a fuel injector that is going to lunch?
When the sho goes into this limp condition, it doesn't try to stall or show any signs of no fuel delivery or lack of air. I think the problem is isolated to 1, 2, or possibly 3 cylinders. Though i don't think the car would have enough power to move itself if it were 3 cyl's.
so, at this point, i open this up to the forum. I hope to document every test, trick and hopefully a resolution so that others can use this if they get into the same or similar situation. Feel free to send me links to other posts, though i have not found another thread with similar symptoms that had a resolution posted.
TIA for your attention and help.

 

[Kean_SHO]

OK, I have had all day at work to simmer on this issue... so here are my thoughts out loud...(for anyone who is thinking i am just repeating SHO 101, please read along and give me your input to put me on the right track).
After reading "PIP, CID and You: SHO Ignition System Basics" (http://www.shotimes.com/php-bin/mod...e=article&sid=251&mode=thread&order=0&thold=0)
I am curious to know if the answer to my problem lives in the information given here.
I have heard the Cam sensor (CID) is a common failure point AND that it can fail without throwing a code to the CEL.
My next place to trouble shoot i think is the CID.
"If you suspect a CID sensor going bad after the engine warms up, its best to start the engine with the sensor connected, verify that all is well, then disconnect the CID and don't turn off the motor. This keeps a flaky CID from mucking up the fuel synchronization until you can get to a garage or home to replace the faulty sensor. "
This was taken from Gary Morrell's post.
This is a fantastic artice for anyone who wants to know about what happens behind the roar of our SHO's.
Am I on the right track? Is there another tree i should be barking up?

 

[dmbturbo69]

I am having same or similar prob on Gen I after warm

 

[Kean_SHO]

Well it wasn't the CID.. the car runs the same. Tried unplugging the CID and starting the car and it ran really crappy with a miss. I am about to pull the coil off and have it tested. Does anyone have any advice or suggestions?

 

[Kean_SHO]

Coil tested fine at autozone... replaced the DIS and it was more peppy with a miss. I pulled each plug wire one at a time and started the car. Each time it ran noticably worse... so i assume i have spark and ignition is not the problem.
can anyone help? please?

 

[shopower90]

how about oil in the plug holes? i had a problem with my car missing too, it would do it when it was cold to but it would get ALOT worse when it was warmed. i talked to NAPA and they wanted over a $100.00 for a set of valve cover gaskets, i just used high temp permitex, hasnt leaked since and there is no more miss.

 

[dpsutphin]

Here's a cheap trick to try if you haven't already. I had the same symptoms in my 1990. After much ado, and several hundred dollars in replacement parts, I replaced the fuel filter, and the problem went away.

Seems there must have been a little trash in the fuel line, or tank. Had to replace it 3 times to get it to go away for good. But it's a $10 part and easy to replace, so it is worth a shot.

Also, check all the wires from your injectors, especially where they contact anything metal, and tape up any bare spots you can find.

Don't know for sure which one of these things fixed mine, but wish I had done them first instead of tune up, cam position sensor, tps sensor, coil pack, etc.