Questions and Answers

Geo Tracker Hesitates, Lost Power Q. Hey, I have a really irritating problem with my 1993 Geo Tracker, standard transmission, 4WD, TBI, and it would be great if you could point me in a direction here because I've pretty much exhausted every other resource. Took it to a local mechanic, he had no idea. Then I took it to the Suzuki dealer in town.

They made it 10 times worse, changed the TPS setting, but when I cranked the TPS all the way clockwise the car would at least have enough power to move again. Anyway, my problem started a few months ago around mid fall when I first noticed brief hesitation under hard acceleration. It only happened once in a while though. There was also slight ping under hard acceleration every so often. This was all annoying, but tolerable.

Over the last couple months the slight hesitation then progressed into moderate hesitation, then intermittent complete loss of power, usually around sharp left turns, then it would idle rough, that progressed into not idling at all. About a two weeks ago it was at the point where it would start, but I had to put my foot half way to the floor, any further and it would stall, and feather the clutch just to be able to move at all. Second gear wasn't even an option because it didn't have enough power to move.

Funny thing is though, it runs PERFECTLY when in open loop mode when you first start the engine. You can mat it and it'll pick up just like when I bought the thing. You can feel the second it warms up and goes into closed loop. Just like somebody simultaneously pulled off two of the spark plug boots. Then you can shut it off, then start it again and it'll go briefly then crap out.

If you start the car and let it idle from a cold engine, it will idle forever. If you drive 100 feet then stop it will idle for about 20 seconds, then start to sputter, at which point maximum engine output has been decreased to about 5 horses, then stall 30 seconds later. There's big time surging as well if you try to give it any gas to keep it from stalling if you've left it idle. I checked the spark plugs after it has stalled and they look beautiful. Anyway, it's to the point where it's not drivable now and is sitting at the mechanic's place but he has no idea so I figured I'd ask the online guru for advice.

I know you're supposed to treat any work previously done as suspect, but here's a list of what has been done or checked. As to the thing you've probably got singled out in your mind as the problem right now, the TPS is fine. The mechanic tested it and so did I. Everything is dead center according to the tolerances given in my Haynes manual. The resistance increases smoothly and linearly with no hiccups at all, and that's with pretty extensive testing. I work on electronics for a living.

The EGR has been tested, then doubted and completely disconnected. Fuel pressure is good. Valve timing is dead on. Spark appears to be strong. I pulled the computer and tested as many components as I could, they're all good. But that's not to say one of the ICs isn't bad because I can't test those. Coolant sensor is good. The distributor has been twisted in every direction with no difference. New plugs, wires, distributor. IAC gasket was blown then replaced, no difference. MAP sensor was replaced.

The exhaust was removed by the dealer and it's not blocked. ECU is giving the all's well. I tried grounding just about everything under the hood to the battery with a set of jumper cables, nothing. I think it's the ECU but my mechanic and some guy I know that eats sleeps and breathes these Trackers both swear that it can't be the ECU.

So basically if you had any new directions to point me in that would be excellent "Got any dynamite?" Anyway, thanks in advance and I apologize for the long winded e-mail.

Joel

A. When I get one of these problems, I try to give the engine what it wants or needs. In other words, try lightly spraying carburetor cleaner into the intake stream while it's gasping to see if the rpm's pick up. If so, then look at the fuel delivery area, possibly the injectors? Clogged fuel filter? Water in fuel tank? Pump starting to go, etc.

Geo's can be very hard to fix with intermittent problems because they rarely have problems and when they do, it's usually not the same problem that the last one you worked on had. Just from your explanation, it sounds to me like it's starving for fuel and you need to find out why. I have seen a few bad injectors on these.