My 95 isn't running right (missing, hesitation, etc.)

[SHOhhhhMan!]

Well, I just bought this 95 MTX with 72k on the clock and it ran great for the first week I had it. Well then I decided to do the de-carbonization treatment with some combustion chamber cleaner. I did that and it ran crappy after I let it sit for 30 mins. It eventually smoothed out almost completely after a day or so. So the other day I took it to the car wash and stupidly (I didn't know!) washed under the hood. I noticed it was missing when I left the wash and checked it out when I got home... sure enough, there was some water boiling in two of the front plug wells. I let it sit overnight and then pulled the two plugs and wires out after I was positive there was no water that would leak into the motor. Strange thing was it that there was this horrible light brown sludge on the connector side of the plugs and inside the wires. It was just like goo and it smelled like carbon/carbon treatment. So I cleaned off the plugs completely and cleaned the gunk out of the wires... put them back in and it ran great for about 25 miles or so. Then last night it started running like crap again. So I came home, parked it, checked the plugs and they looked fine; no gunk, no oil in the wells, and the plug wires were good too. I pulled them all out today and did the same cleaning routine as before but on all 3 plugs on the front of the motor. Took it out and drove it... ran fine for about 2 minutes then started to miss at medium to full throttle like it has been. It feels like it's running on 4 or 5 cylinders and sorta chugs like it starts firing on all cylinders for a second.

So I brought it home, read a lot of stuff on the forums here and am still kinda stumped since I just went outside and pulled some codes too...

KOER:
-225 - Knock sensor not detected during dynamic response
-536 - Brake On/Off circuit failure not actuated during KOER test

And these codes also showed up as Memory DTCs...
-157 - Mass Air Flow Sensor below minimum voltage
-528 - Clutch Switch Circuit failure
-542 - Fuel Pump secondary circuit failure control module to ground

And KOEO came up with 111 - Pass

So what's next? I haven't been able to access the plugs on the rear of the motor to check them. Should I just assume the worst and go buy some new plugs and maybe wires and get an oil change? (I'd hate to replace the wires since they're brand new from the previous owner.) I'm going to have to buy new plugs anyway since the car has AC DELCO plugs in it for some reason.

 

[SHOhhhhMan!]

Well, I just pulled off the intake manifold. Is there anything I should be doing while it's off?

 

[projectSHO89]

Well, I just pulled off the intake manifold. Is there anything I should be doing while it's off?

Clean the BACK 3 plug wells. You have only done half the job.

Install new plugs. I'd suggest the Motorcraft ones unless you have a specific reason for using something else. Clean the wires thoroughly, maybe they will be fine. Check for oil in the plug wells.

Use dielectric grease on the plugs/wires.

Avoid power washing your engine unless you understand fully the risks and can deal with them.

The only code of any significance is the 157. I would suspect...water in the MAF connector first. Clean and dry it out, then use dielectric grease on the connector. If the 157 remains, try cleaning the MAF sensor element before considering its replacement. If the 157 continues, unplug the MAF and run the engine to see if driveability improves. If it does, then the MAF sensor is suspect.

Steve

 

[AutoSHO]

Haha... Yeah, don't wash the motor with a hose and not clean out the plug wells. Thats what is causing your chugging problem. Sounds like they had a little oil in them too if its now brown sludge. Get that cleaned out of there and it *should* take care of it.

 

[SHOhhhhMan!]

Well, it should be taken care of later today. I need to go buy some motorcraft plugs since the AC Delcos in there aren't gonna cut it. I pulled the rear plugs last night and yeah, they were UGLY; like 2x as bad as the front ones ever were. I think I figured out part of the problem though... the plugs don't feel like they're torqued down tight either. Two of the plugs on the back (the two that were really nasty) had like 1lb/ft of torque on them. I could pretty much remove them without the help of a ratchet if I wanted to. All the intake gaskets and rings are good, so my only explaination for the gunk in there is that the carbon cleaner and oil have been getting pushed up into the plug wells on compression thanks to the poorly torqued plugs. I'll clean stuff up and get some new plugs in there and see how it does over the next week or so. Hopefully this should solve my problem.

I'll keep you guys updated. I have some pics of my nasty plugs I took last night, so I'll post those up later today.

 

[AutoSHO]

Make sure you didn't let any of that stuff down into the cylinders

Next Thursday is the Colorado SHO Club meeting - are you free? Meeting starts at 7 pm at McCoy's Restaurant right off I-70 and Federal.

 

[twr]

You might end up replacing the wires too.

Edit: And what Chris said about the meeting

 

[SHOhhhhMan!]

Yep, I'll be at the next meeting. What's McCoy's like? I've never been there. Italian food I hope?

 

[twr]

Yep, I'll be at the next meeting. What's McCoy's like? I've never been there. Italian food I hope?

Hahaha, no. American and Mexican. Pretty good food.

 

[AutoSHO]

I go for the great car BS, but the food's good too, and we should have a great turnout.

 

[SHOhhhhMan!]

Well, it's running like it should again. I cleaned out my plug wires with q-tips until I wasn't able to get anything to come out on the tip. Then I went to O'Mera and bought 6 motorcrafts and put them in. Checked my intake manifold gaskets and they all look nice and new and aren't pushing oil through anywhere. I drove the car about 100mi so far today on a little trip up to Loveland and Greeley and it's still running like a champ. We'll see if it stays that way over the next week.

 

[AutoSHO]

If you came that far north you shoulda come up to Ft. Collins so I can see it!