Help! Engine stumbles under load

[pvtschultz]

Just started the other night. Whenever the car is under low RPM travel and I give it gas, just enough not to make it kick down, the engine stumbles. Quite noticably. I did a quick search and came up with the TPS, any other suggestions??? Plugs and wires have 26k, and I'm sure that the coils are stock...127xxx miles. She's getting old, I know, but was doing so well.

[Skinny]

If it's not the TPS, it could be one of those coil packs causing a misfire. But I doubt it would be a misfire if you're only stumbling under a light load. Are you setting the SES light? If you were that would make diagnosing the problem alot easier, but we'll see what we can do. I know checking the plugs in that 95 will be a pain in the a*s but it might be worth doing. If you don't have a Haynes or Chilton's manual, I'd suggest getting one. In there you can read how to check the various sensors. Check out that TPS sensor first, and if that's not the problem you can check the resistance on the wires and the coil packs. However, like I said, if you're only stumbling under light throttle I doubt it would be a misfire. Check out the TPS and then update us.

[blackfire99]

Hey, I have a 99 M5, I replaced the fuel filter, plugs, and pcv...solved the problem, It just needed a tune up I suppose. Mine was basically doing the same thing yours is, just a different tranny. Keep it simple...

jason

[Dojo2000]

http://www.camarov6.com/cgi-bin/ulti...&f=16&t=000690

[pvtschultz]

Whelp, small update. I drove it all the way to MN (600 miles total) trying to baby it to keep it from missing. Then I noticed today on my way home from school, it doesn't miss at all when the engine is cold. I put my foot into it good and didn't miss a beat. I am going to try the night time inspection and see if it is arching. The plugs and wires are only a year or so old as is the filter. So I'll see if the mechanic installed them sloppy. I did trip a code, and I know that I got at least one missfire reading so I guess it is off to autozone tomorrow, I'll let you know what they say.

[pvtschultz]

Hopefully someone will see this. But I took my car to the very generous people at Autozone to have my computer scanned (I really need to buy a scan tool). And the codes are very common ones: Misfire cylinder 3, and p1406 faulty EGR valve. I checked the contacts on the coils and they are all shiney. My question now is, how reliable is the codes. Is it going to be number three and how are they labled now. Is it 1,2,3 from front to back on the driver's side, or is it 1,3,5 or 2,4,6?

[Skinny]

Cyl 3 is the middle cylinder on the driver side. Check that wire and plug. If the code trips again, get it scanned again. If the misfire jumps to cyl 6, swap the coil pack with the one next to it (labeled 5/2). Then see if the miss changes to cyl 5 or 2. If it does, the coil pack is your problem. [img]graemlins/burnout.gif[/img]

[pvtschultz]

Thanxs, that is all for the time being

[cb1101]

hey man i just went through all that with the stumbling...exactly what you mentioned.

it ended up being that # 3 wire was fried causeing little misfires and giving me a headache.

car runs like new now [img]graemlins/fluffy.gif[/img]

[pvtschultz]

I am going to look at it tonight after school. The plugs should still be decent yet, but I'm sure that wire likes to rest on the manifold. I should just go and get one new wire, that would be odd.

Hopefully we will be able to get a nice archive of this one because it seems to be kind of common.