rpm fluctuation at highway speeds

[nw_hiker_man]

Was cruising along the highway at about 60 mph in my 95 Trans Sport when the RPM's starting to fluctuate. Looked like it was shifting in and out of 4th. No bucking. Just a 500 or so rpm shift. Finally sputtered and died as I pulled over to the side of the road. As it was dying, the check engine flashed (I'm guessing that was because the engine died.) ABS light came on and stayed on. Started right back up and I was able to get to the next exit without it dying again. (It did fluctuate a couple more times when I was at higher speeds.) Drove it home on surface streets with no problems. It shifted fine. ABS light is still on. Any ideas what the problem might be?

[dwalmop]

Are you sure it was a gear shift you were feeling? Or was it possibly just the torque converter? I can't think of anything right off the top of my head but if you cut fuel off the tc will "unlock," and "re-lock" when fuel is constant again. The engine sputtering and dying could obviously be from lack of fuel somehow.....just throwing ideas out there. Not sure about ABS light. ECM problems causing everything maybe? Bring it somewhere to get your stored codes read and let us know.

[LMP]

I agree with that opinion.
If the diagnostic plug near the parking brake release has contacts a,b, and m, this is OBD1 and you can "flash" the codes yourself by connecting A and B together and turning the key on.
see www.avigex.ca/xport/plug.jpg

IF THE PLUG DOES NOT SHOW EXACT CONNECTIONS as shown on photo, then you cannot flash the codes.

If similar then:
THe check engine light will show code 12 first (one flash then 2 flashes) a few times, then start flashing the codes , like 54 is 5 flashes then 4 . Once finished, it flashes 12 again and repeats the codes.
YOu can check the meaning of codes (if it is a 3800) at
www.avigex.ca/xport/3800codes

[nw_hiker_man]

Looks like it was a bad EGR valve. Pretty common problem I hear. ABS light went out. Thanks for the input.

[LMP]

mmm..a few questions for the benefit of the collectivity...
. How did you get the diagnostic?
. Did you have the EGR valve changed? At what price? 3.1 or 3.8?
. Did the ABS light go out by itself or was it cleared by the service with scan tool?

[nw_hiker_man]

It's the 3.8 Had my mechanic diagnose it. He couldn't get the engine to act up. (I had driven about 100 miles before it acted up.) The code was stored for an EGR fault. Replaced it. The part itself was something like $270. ABS light went off on its own. Might be my center mounted brake light that's out.

[nw_hiker_man]

Well... I was wrong. EGR didn't fix it. My guess it's something like a fuel pump just starting to go bad. I guess I'll have to wait until it does it consistantly enough to make a diagnosis. :-(

Any other thoughts.