Mysterious problem

I have a 1998 Toyota Camry with an intermittent problem that’s existed for over three years. My local dealer has checked the car out and found nothing wrong. Of course, the problem doesn’t occur when he has the car, but it’s so fleeting I doubt he’d find anything even if it did.

Every once in a while, on the order of once every 100 miles or so, the car loses power. It doesn’t stall, it just doesn’t respond when I push on the gas pedal. This will last anywhere from a few seconds to a minute or so. Sometimes it will start to respond, sort of chug along for a few seconds, and then falter again, or it will respond for few hundred feet and then lose power again. Needless to say, when this occurs pulling out into traffic it’s a dangerous situation. I’ve tried to find a common variable for when this occurs (full/low gas tank, cold/hot weather, level/hill driving, slow/high speed, etc.), but nothing is consistent. The only thing I noticed is that the engine doesn’t stall when this happens. If I pull over and put the car in neutral the engine revs fine.

Some things I’ve considered: something in the gas tank, transmission problem, fuel delivery problem. I’m not sure what the dealer checked when I had the car in, but I assume he looked at things like filters. His only suggestion is bring the car in again, and again, and again. I’m down almost $150 with him and still have no clue what’s causing this.

Any suggestions as to what might be going on here would be appreciated.

Craig

Reply to
Craigwc
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It sounds like a fuel delivery problem. However, the fact that it is intermittent is puzzling. This would argue against a problem with the fuel filter or fuel pump since that should be more consistently bad. A plugged exhaust system can also act like this, except for the intermittent part.

In my opinion it has to be something electronic in the fuel delivery system. Maybe the throttle position sensor. Or I suppose it could be the fuel pressure regulator.

This sounds like something that the dealer needs to investigate. Some dealers have "flight recorders" that they can connect to the OBDII connector. These can record engine parameters continuously. When the problem occurs, the driver triggers the recorder to save the parameters at the moment the problem occurs. Something like this is probably what you need. Maybe you should check with a different dealer.

I have a Davis Carchip which has the ability to record some parameters. Something like this might help you narrow the problem down.

Ed

Every once in a while, on the order of once every 100 miles or so, the car loses power. It doesn?t stall, it just doesn?t respond when I push on the gas pedal. This will last anywhere from a few seconds to a minute or so. Sometimes it will start to respond, sort of chug along for a few seconds, and then falter again, or it will respond for few hundred feet and then lose power again. Needless to say, when this occurs pulling out into traffic it?s a dangerous situation. I?ve tried to find a common variable for when this occurs (full/low gas tank, cold/hot weather, level/hill driving, slow/high speed, etc.), but nothing is consistent. The only thing I noticed is that the engine doesn?t stall when this happens. If I pull over and put the car in neutral the engine revs fine.

Some things I?ve considered: something in the gas tank, transmission problem, fuel delivery problem. I?m not sure what the dealer checked when I had the car in, but I assume he looked at things like filters. His only suggestion is bring the car in again, and again, and again. I?m down almost $150 with him and still have no clue what?s causing this.

Any suggestions as to what might be going on here would be appreciated.

Craig

Reply to
C. E. White

Sounds to me electrical, the fact it idles and at No load revs is exactly what happend to me, it was one bad plug wire. Plugs need less current with little gas, or a small load, when you are driving you need alot of gas and good spark to fire it. What will cause this is a weak coil, bad plug or wire and maybe the ignition module. My coil would do this all the time when it rained or was real humid, I had a loose cap. Many old models had the coil under the cap that got contaminated with oil as the car got old, cleaning the coil often worked, but its shutting down when current is needed, a short is occuring somewhere.

Reply to
ransley

Does it rev fine in neutral every time??? If so could be a tranny problem.

Chas

Reply to
m6onz5a

The tranny doesnt have anything to do with engine spark or fuel delivery

Reply to
ransley

A 1998 vehicle should be OBD-II compliant. Right after one of these incidents there's a good chance that you'd at least have a "pending" error code set, even if it didn't happen enough times to actually set the code. Get a code reader and pull codes *right* after it happens. My bet is on something like the throttle position sensor or the MAP (or MAF, whichever this vehicle uses) sensor.

Could also be a fuel pump about to fail, or a fuel pump relay cutting out letting the fuel pressure drop too low. THAT one won't set a code, unfortunately.

Reply to
Steve

Symptoms described are exactly those of our Russian-built Lada when 3 or 4 years old (1980) caused by rust in the fuel system, spalled off the surface of the fuel tank. (When we emptied the tank and removed it, shaking it sounded like maracas.)

Reply to
Don Phillipson

Check fuel pump amperage draw and see if you have a loaded fuel filter or weak fuel pump.

Throttle body position sensor can be checked with an ohmmeter easily.

FYI, check Autozone's free repair guide.

Reply to
johngdole

I had an old car that would run OK most of the time but would stall out going up a long hill or when I'd accelerate for awhile. It turned out to be a fuel filter restricting, but not cutting off, the fuel to the carburetor. The engine could run for a while on what gas there was in the carb as long as the reduced flow was sufficient to refill it.

Every once in a while, on the order of once every 100 miles or so, the car loses power. It doesnt stall, it just doesnt respond when I push on the gas pedal. This will last anywhere from a few seconds to a minute or so. Sometimes it will start to respond, sort of chug along for a few seconds, and then falter again, or it will respond for few hundred feet and then lose power again. Needless to say, when this occurs pulling out into traffic its a dangerous situation. Ive tried to find a common variable for when this occurs (full/low gas tank, cold/hot weather, level/hill driving, slow/high speed, etc.), but nothing is consistent. The only thing I noticed is that the engine doesnt stall when this happens. If I pull over and put the car in neutral the engine revs fine.

Some things Ive considered: something in the gas tank, transmission problem, fuel delivery problem. Im not sure what the dealer checked when I had the car in, but I assume he looked at things like filters. His only suggestion is bring the car in again, and again, and again. Im down almost $150 with him and still have no clue whats causing this.

Any suggestions as to what might be going on here would be appreciated.

Craig

Reply to
Stubby

How would I apply your suggestion in a real life? What current should it read when good and what when weak? What current should it read when the fuel filter is loaded?

Reply to
Pszemol

Replace the fuel filter. Mine was clogged with a deep red fuel additive during the '74 fuel shortage. I've never played with the fuel pump but it is probably easiest to replace it, also.

Reply to
Stubby

I still say its spark since I have experianced many spark issues, simple test, get an inductive spark tester and extend the wire so you can have it in the car , because you said it needs a load to missfire, when it happens hook it up.

Reply to
ransley

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