santa06

Maybe vacuum, but usually they run like crap but still start with vac problems.

Give the intake a squirt of gas or even starter fluid and it should run for one or two seconds.

Fuel , spark and timing are the essentials.

Frank_Ford

See if you miss sounds like it might be the EGR valve as follows

Too much EGR flow tends to weaken combustion , causing the engine to run rough or stop. When EGR flow is excessive, the engine can stop after a cold start or at idle after deceleration, the vehicle can surge at cruising speeds or the idle may be rough. If the EGR valve remains constantly open, the engine may not idle at all.

I understand that you have determined that the EGR diaphragm is moving when you attach a vacuum line to it. The remaining possibility is to clean the valve with a wire brush or scraper. To do this, you will have to remove it. Also, make sure that EGR pipe that goes from the manifold to the EGR valve is also not plugged up.

Additionally, I would be a little concerned about that number 6 and 8 cylinder misfire you had in your initial post. If it were me, I would do a compression check on the number 6 cylinder because this is easy to get at. If compression is low, put in a little oil in cylinder and test again. If pressure goes up, the loss is in the rings and not a valve or head gasket problem.

I wish I could give you some better information and I hope I am not leading you in the wrong direction. I have found from experience that some of these problems are hard to detect. When I have finally had enough, I have a really great mechanic in Joe Malcolm who is also an old guy like me and I am sure he can fix it properly at a fair price. Perhaps you have someone in your area like him.

udderbrudder

Try applying vacuum to the EGR with engine idling. It should stumble/stall. If it doesn't have much/any affect- it may already be stuck open with carbon. I've seen this more than once.
If the engine has a misfire it won't always set a code. I've had this issue with mine. But you can try unplugging COPs one-at-a-time, looking for the one that has little/no affect on RPM.

ldefoggi

X2!

I've done that before as a "diagnostic" before... not sure why I din't think of it earlier... nice idea! I also like the idea of pulling vacuum on the egr while its running.

77AZ

Well I finally got around to driving for about 20 minutes today. Got home and checked underneath, glowing cats on the drivers side. Anyone know of the cheapest fix besides buying a whole new Y pipe??

udderbrudder

The cats are not the problem! Cylinder misfires will cause the cats to glow like that. When the unburned fuel and oxygen from the miss gets to the cat it ignites-causing extreme temp. However, since only the left side cat got red, you've just determined that the misfire is on bank 2 (cylinders 5,6,7 or 8). Your're half-way there, LOL.
BTW if your cats are damaged, it's because of the misfiring. If you replace the cats before fixing the misfire, you may damage the new one(s) and have to replace them again (not cheap!). Just sayin.

77AZ

Yeah you're right. It's back to square one. Why won't it throw a code?!?

Azure_

Have you checked your voltage on the TPS? Might be bad, but usually those will throw a code, but seeing as you have pretty much checked everything else try that.

http://www.buzzle.com/articles/sympt...on-sensor.html

77AZ

Took it down to the dealership yesterday around noon for a $100 diagnosis. Hadn't heard back by 5pm so I called down and the guy said his mechanic had it for a few hours but will need more time and would continue to look at this morning. UGH! Any bets on what it is? lol

77AZ

Welp. Always buy Motorcraft coils. Turned out 2 of the 8 coils I bought off Amazon were bad out of the box. Dealer read 7 & 8 misfire (used their fancy equipment since there was no CEL on) so the tech swapped 7 & 8 coils to 5 & 6 and then 5 & 6 tested bad. My service adviser was really cool and said he would keep them there so they would be easy for me to replace, he knew I was a DIY guy. They wanted $587 to replace the 2 bad coils. Paid the $100 diagnosis fee and came home grabbed 2 of my old originals hoping they weren't bad and she is running like a champ so far. I will keep you guys posted. Is there a way to bench test a coil to see if its any good? I have a feeling I am going to need some of them in the future.