Zero10

So, when I get one problem fixed, another pops up.... I stopped the squealing PS belt by removing it, then the car starts to run terribly.

It has happened twice in the past, for maybe 5 minutes or so, it will stumble BAD. It will act like I have 1 dead cylinder until it warms up, or until I drive it hard. Usually I wait for it to warm up, and make one hard run to 5500RPM, and when I shift I get a big bang from behind me, and everything is great. Now, I can't get it to go away. It's haunted me for the past 50 miles. I know I don't practice the best way to clear a mis-fire, but it always kind of seemed like a fouled plug in the past, which driving it hard seems to clear in very short order.

I can't identify for certain what cylinder the problem is on, perhaps I have several problems ganging up on me? Here is what I know.

Bad stumble developed yesterday night. Started the car to go to the dentist, and right from the get-go it was stumbling bad. When I got back home, I pulled plugs #1 and #4 (the usual suspects with this motor) expecting #4 to be horribly fouled, and planning to swap it with #1 to clean it up again (been doing this for a while). I pull #4, and find it only lightly oily, with no real build-up. So, I pull #1, and find it covered in large white deposits.

At this point I start thinking it's head gasket. Coolant level hasn't dropped a hair in those 50 miles it's run terribly, so I don't know?...

Next thought, spark. I pull each plug wire one at a time, take a spare spark plug, and wedge it under my strut tower bar, so I get a good ground, and hook the wire on to it. I get what appears to be a good spark on all 4 cylinders, although #3 seemed a little intermittant. So, I move on to fuel. I lift the fuel rail out, flip it over, and have my dad crank the car a few times. Fuel spray couldn't be better, nice and even between all 4 injectors, no leaks, no abnormal spray patterns, etc. Back goes the fuel rail. Upon re-installation, I find one of my spark plug wires seems a little bit flat in one area. Nothing too severe, but (perhaps by co-incidence?) it was the #3 plug wire. I pull it up, round it out as best as I can, put everything back together, and changed the #1 plug to a new one. I took it out for a spin, and the miss is noticeably better, but it's still there. It seriously takes about 25 seconds to go from 2000RPM to 5500RPM in first gear. This is not good! Before it was like having a rev limiter at around 4500-5000RPM, with a really slow cut-off, it would take maybe 60 seconds to hit 5000RPM.
Also, I can't top 1.4-1.5 bar of boost (too dark to see my aftermarket gauge, it would maybe read 7-8psi? I found the factory gauge is somewhat accurate between 1.2 and 1.8 bar). Even then, it takes until around 4500RPM to get what is now full boost.

My exhaust is noticeably louder. Perhaps due to the misfire I am getting many small backfires?

I don't have my compression tester with me or I would have checked that as well.

Any suggestions? I don't even know what to check next.
The #3 plug was a nice tan color, nothing seemed too strange there. Not even certain the problem is the #3 cylinder, maybe it's #1 with the white plug?...

I hate it when I get these hard-to-solve problems like this.

Peckster

[QUOTE=Zero10] I stopped the squealing PS belt by removing it, then the car starts to run terribly.
QUOTE]

Did you try adjusting the belt first?

Hard to tell what your problem is without more info, I['d stop drivign it befotre you do soem swerious dmage, and boprrow a comptression tester. What do tyou mean by a "flat" plug lead?

Try replacing your plugs, rotor and distributor cap, or at least check them out.

Did the car start to run badly immediately after you removed the belt? If so, you probably did soemthign else to it while you were in there, go back and recheck where you were working.

cantresjr

try cheking the connector for both the reference sensor and speed sensor. mine were gone and the terminals woul touch every now and then and cuase a missfire. they shuold be located near the firewall behind the intake manifold.

racerx7

Putting a plug wire to ground is not a good way to test a modern
ignition system. You need to get a cheap spark tester. It will require your ignition system to have at least 25k to jump the plug gap.

something like this. ( go to the bottom of the page)
http://www.matcotools.com/Catalog/to...&page=3&#30796

toddk911

Let the engine idle in the dark (real dark) and look for archs and blue flashes.

Zero10

No arcing from the plug wires. What I mean by flat, is one of the plug wires was squished such that it was about 1/2" wide and 1/8" thick, looked pretty bad, but it's now pretty much returned to a round shape, and I found the problem, finally!!

It was a bad plug. The ceramic had cracked way down from the insulator, and it was arcing inside the plug itself. I changed the one plug and the problem went away completely. Here's the new problem. It happened again.

So, time for the run-down on this story.
I rebuilt the engine, and from the get-go it burned oil like crazy on #4. It used to foul plugs weekly, so I would swap plugs #1 and #4 every week to keep it from fouling too badly. Worked well for a while. One day, the metal shell seperated from the ceramic part of one spark plug, causing a severe loss of compression on one cylinder, which blew the spark plug boot off, and you can guess how well it ran. So, I changed the one plug. 500-800 miles later, another plug fails in a similar fashion, I could spin the center part of the plug while holding the metal ring. I go back to NAPA, get told that the box of plugs must have been dropped. So, I pull out an old beru ultra plug I had (only ~1000 miles on it) and dropped it in, since I was out of Bosch Copper plugs. Now that plug has failed, and I changed it again. I bought a single champion plug, since I was really in a pinch when it failed. And guess what, this one has broken too. I am very gentle on my spark plugs, and I find it strange that all of these plugs have failed while in cylinder #4. Is this possibly from my oil burning problem? Maybe I get too much oil in the cylinder, and it causes the cylinder pressure to get too high, and the spark plug is the weakest link?... I have no idea.

This is now 3 different brands of plugs that have failed on this cylinder, all in a similar fashion. Some the ceramic cracks, and you can see carbon and oil coming through the crack, and it shorts through it as well, while others, the entire ceramic part breaks free..

This hurts my brain...