Problems with my car...

[martattack]

Ok, so it all started when I was going up to Seattle this last weekend for a car show. I stopped into a McDonalds, and when i came back out, my car was running like crap.. seemed to be in Limp-Home mode. the CEL was on, but it was from a previous trip (bowden cable on transmission), so there may have been another trip, but I'm not sure.

I instantly think it's the MAS because the car had been starting funny when first started for the morning, and also when leaving from getting off work, for the last couple of months. I had this same problem in my older Volvo and it turned out to be the MAS.

So I go to the dealership and buy a new one, plug it in and it runs a little better, but still not very well. So, I figured that perhaps the plugs got fouled when the old MAS went dead. I tried getting onto the freeway, when it seemed like it all cleared up. The car was pulling harder than it had ever before. That didn't last long.. About 10 minutes later, the car started running poorly again.

I disconnected the battery for 10 minutes to clear the CEL to hopefully see it come up again.. So far it hasn't.

I bought new plug wires and coil ends, and it is still running poorly. Not really sure what is going on.

On a side note, I have noticed that the electronic vacuum pump in the back turns on about every 15 seconds. I'm not sure what that would have to do with it running poorly, but maybe someone has had a similar experience. I really don't want to go replacing more parts and spending more money. I'm going to try swaping around the ignition coils to see if the problem may be a bad coil pack. I will chime in with that tomorrow.

Any help is appreciated!

Thanks

Martin

by the way, it is a 1994 C280

[Denlasoul]

Have you been able to pull any codes? Maybe we could get together this weekend and troubleshoot.

[JAY4]

What Den said. If it were me I wouldn't keep throwing money and parts at the car and hopeing for the best. Get it scanned, with luck it will pin point the problem. Hope you get your car straight soon--best of luck.

[martattack]

I'm going to limp it to Autozone... Only about 5 minutes away, and see if I can get any codes pulled.

The CEL isn't on right now, so does taht mean there won't be any codes? Or can codes still be active without the CEL?

If I don't get it figured out before this weekend, I would definitely be down for that Dennis. (If you don't mind the drive to Olympia).

I will get back to you guys tomorrow when I figure out more info.



What Den said. If it were me I wouldn't keep throwing money and parts at the car and hopeing for the best

Well the plug wires were for sure something I was going to replace before this whole ordeal went down, so I'm not too worried about that, and the MAS, I knew was on it's way out.. not exactly what I wanted to spend $350 on, but some justification I suppose.


Martin

[jnenad16]

Oxygen sensor. when my O2 went out, the car had no power at all.

nenad

[benzaddict]

Sounds like you have a vacuum leak. Your PSE locking pump running a lot is a dead giveaway. These early W202's have "manifold vacuum assist" from the locking pump which keeps the vacuum reservoir in the r/f fender full of vacuum in case the engine can't, for things like climate control and upshift delay. It sounds like you already know that your upshift delay pod on the bowden cable is leaking, but that shouldn't be a problem unless your relay solenoid is stuck open.

Check for vacuum leaks around the intake. If you've done an oil change recently check the line in the rear, it gets popped off often while changing the filter. Also check the line going over to the right fender and vacuum block at the fender to make sure nothing is loose. Check the line that goes across the front to the EGR and air injection solenoid relays to make sure it hasn't broken. Check the large line going to the purge valve on the driver's fender by the washer tank to make sure it's connected and the purge valve is cycling/pulsing. You should hear/feel it pulse rapidly intermitt at idle, if it's idled for more than 5 minutes and still hasn't pulsed, it's most likely stuck open creating a huge vacuum leak.

Note that a vacuum leak will give you many of the same symptoms as a bad air mass sensor because the engine is recieving unmetered air. If you can't find any vacuum leaks, then try and get codes pulled. There still may be codes stored even if the CEL is not on, it depends on the severity of the fault. If you have any other questions, shoot me an email, it's in my profile. Good luck.....

[martattack]

Ok, I'm still in the process of checking for vacuum leaks. I did find one leak.. The one behind the Oil filter became disconnected from the intake manifold (what is that one for anyway?). I plugged it back into the nipple on the manifold and it was still running rough and the vacuum pump was still running every 7 seconds or so. I heard a "breathing" sound coming from the passenger footwell area. Could a leak on one of those vacuum hoses cause the engine to run rough like that?


Update 2: When I was about to check to see if the purge valve was operating, I tried starting, and now it won't even really idle. It kinda flutters and when I get it gas, it sounds like it's running extremely rough.

Going to keep fiddling with it. Any more ideas would be greatly appreciated. It seems to be a couple problems combined.

EDIT: Another Update:

Appears that my coil pack wiring harness may be degrading.. I tried unplugging the coil pack wires (not plug wires) so that it would run the same as it was, and when i got to the back coil pack, there was absolutely no change with it plugged in.. Upon further inspection, the coil pack wire is broken. going to try to repair it and see if that fixes the problem.
This seems to be a problem of wiring and vacuum. Grrrr

Anyone have hook-ups on a wiring harness ??


Martin

[davis449]

I was thinking coil pack cause this was sounding very similar to what happened to me when I was driving the 99 down here from Chicago. The tech told me to unplug the cylinders one at a time and if the RPM's don't drop when you do, you've pin pointed it to that particular cylinder and it's gonna be the plug, wire, or coil pack. My coil pack was degraded and that was causing a misfire, hence no power, CEL, and really crappy idle. It happened all of the sudden too, just like yours did. I was happy and doing 115 on I-55 coming into St. Louis (me and a VW Golf) and everything was fine, I stopped to visit my grandparents for 2 hours, got in the car, filled up, drove about 20 miles, and all of sudden, no power and CEL came on with the car shaking like hell.

[martattack]

It does have to do with the coil pack, but it is definitely the wiring harness. Completely erroded away the insulation on the wires. Check out these pictures.

http://202tech.mkosonen.com/misc/wires1.jpg

http://202tech.mkosonen.com/misc/wires2.jpg


Any hook-ups on wiring harnesses? How much do they normally cost? I've got no problems installing it myself, just need the parts.

I'm going to temporarily re-wire the coilpacks with my own wire until I can justify spending lots of money on a whole new wiring harness.

[benzaddict]

If you want I can check and see how much I can get one for at work, do you have a way to get to seattle to pick it up?

[martattack]

Originally posted by benzaddict
If you want I can check and see how much I can get one for at work, do you have a way to get to seattle to pick it up?

I appreciate you checkin that out for me. I would be able to get up there if I had to. I'm actually heading east of the mountains next week, so I may be up that way anyway. I have to drop off my old MAF as a core at Phil Smart. Is that where you work?

Nothing set in stone, but a price check would be great if you could!

Thanks again

Martin

[benzaddict]

Yeah, I'm at Phil Smart, I'll check tomorrow and let you know.

[martattack]

Just as an update. I did a temporary fix on the wiring harness so I can drive to work while I wait for a new wiring harness that I ordered. Next week will be installing a new wiring harness.

Here is a picture of the re-wired coil packs.

http://202tech.mkosonen.com/misc/tempfix.jpg

[Beau M]

Did your re-wire job get it running right again?

[martattack]

Originally posted by Beau M
Did your re-wire job get it running right again?

It's running great right now. I just wonder what's going to be next for the wiring harness to let go. Going to just replace it and not worry.