HELP! She's dead in the driveway
 

Only by the grace of God was I able to make it home today.

My beloved 92 SVX 5sp with 145,000 miles decided to act up today. I suspect that I have a bad TPS, but would like some feedback from others as a confirmation. On my 40 mile commute home today, around 15 miles from home I was driving 75 with the AC on and cruise control. Suddenly the engine started to buck violently. No CEL, nothing. I turned off the AC and slowed. Any steady throttle application resulted in violent shaking. I downshifted into 4th and floored it and it seemed fine, but in 5th and part throttle, instant violent bucking. So I decided to drive the rest of the way in 4th at 65MPH. About 5 miles down the road, the car started to buck violently in 4th, even at the higher RPM. So, I downshift to 3rd, floor it and it seems to be OK in that gear. Just a few miles further and the same thing starts to happen in 3rd gear. I stepped on the clutch while moving at 55MPH to see if the engine would idle and it would not. I started it back up and barely made it to the next exit. When the car rolled to a stop, I tried to start it. It actually started, but would not rev; no amount of pumping the gas would make it rev and it died again. It sounded like a VW bug.

By this time, I caught the attendtion of a TN DOT service truck. He stopped to help, but I told him there wasn't much he could do. I popped the hood and disconnected and reconnected the TPS connector. I noticed that the pre-cats were smoking, but I assume that they were running hot from the raw unburned gas that was getting to them.

I got back in the car and it started, but I had to 'clear' it by revving it to 6K. When it idled, it did so roughly. I tried to make a mad dash home (4 more miles) and succeeded, but had the rev the heck out of it at every stop sign to keep it from dying.

I believe it's the TPS. My car has 145,000 miles. I put new platinum plugs in it at 120K. It has a new main cat that I installed at 100K. In addition, I now here a tinny rattle that wasn't there before (when coasting and not under load). I may have blown up the innards of the cats.

Feedback anyone? Does this sound familiar?
Has anyone had an issue with clogged pre-cats or ones that have blown out? My main cat only has 40K.

I will pull the TPS and take it to work tomorrow to test it and hope that that's all it is. If replacing it fixes it, I intend to remove the Y-pipe and inspect the innards of the main cat and listen for any funny rattles. Any additional advice from the SVX knowlegeable is greatly appreciated.

I smell MAF problems, not TPS ones.

hey gsodonis(i think i got it right ) I had almost the exact problem with my car. it was the MAF it had fried. try cleaning it following the directions in the "how to" docs and you might be able to save it best guess, sorry. try svxmotorsports.com if it is still dead they do have one at the moment .

Maf
 

More than likely. some say the component can be cleaned but not sure. When mine did that, I just replaced the MAF and it workes like a dream ever since. There is information about cleaning it on the network but I know nothing about how to do it or if it would even work for you.
Good luck!!!
kwren

Thanks for the tips.
I had cleaned it about a year ago following the how-to.
FYI. after the car cooled down for a couple of hours, it started up like normal. I hear some serious rattling (like a babies rattle) in the exhaust. I'm pretty sure all of the detonation in the cats has blown something apart inside. I want to cure the drivability problem first, then I'll find a n exhaust shop that can fab me a new Y-pipe with precats out of stainless.

I checked out the MAF cleaning procedure and it looked pretty good. I think that spraying some contact cleaner on the plugs might also help.

http://www.subaru-svx.net/photos/files/How-To/41607.pdf

Greg