losing power

[Ray Bone]

just bought a 95SW 55000miles, driving on the hightway yesterday feel it was losing power when I switched gear from 4th to 3rd, idle stayed at 2 won't pick up for about 30sec, then it start pick up the speed again, it was about 50 miles per hr, any idea? i thought it came from the clutch? Help guys!!

[Davis]

First thing to compare is are the rpms going up without increasing speed. If so, then it is a clutch issue. If the rpms are staying down and you are only slowly picking up speed, then it is a power issue.

On the clutch issue, you know what to do. On the power issue, is it intermittant or fully constant loss of power. If intermittant, look to the computer controlled equiptment for the most part such as injectors, throttle position sensor and stepper motor. If all the time, check your fuel filter, engine compression, coil, and plugs.

If, regardless of gear, if this is happening around a specific RPM (such as 1800-2200), then have your alternator checked for proper operation--if a zenier diode is bad, it can leak AC into the system and cause false injector firing causing this symtom.

It could also be a worn cam, but at that mileage doubtful.

If it was me, I would start by looking at my plugs--they can tell alot about problems (this would also be when I would check compression). Next, the fuel filter and rotor/cap (did 95's run a distributor?). I would clean my stepper motor and try again.

Let us know what you find for other symtoms and best of luck.

[Abrooks]

I'd also run the ignition system check from the manual to rule out the ignition module. Early stages of my first module failing were exactly the same (eventually, thanks to Pendy, I realized it was from a failing alternator). The trick is hoping that the problem replicates when you're running the test.

Good luck,

Tony

[Ray Bone]

the third time that happened, i heard a air leaking sound, as soon the noise stop, the engine is picking up again.
thank you so much
Ray

[Hans]

Hmmm. Maybe an air leak somewhere between the intake manifold and the Mass Air sensor? Could definitely do that.

-Hans

[Davis]

If it is an air leak, you can find it by spraying carb cleaner around the engine bay around all the areas that it could be leaking--if you have a leak, the rpm of the engine will increase.

[Antonios]

I just drove my D90 from Baltimore to Miami and had a similar problem. I'd be driving at a steady speed around 70-75mph and all of a sudden it would feel as though I took my foot off the gas when I hadn't moved. Sometimes I could tap the gas pedal a few times and it would come back and sometimes I would have to pull over. Also If I held the pedal in place while this was happening I would start to smell fuel.

Another time it happened was different. The truck started hesitating at speed like I was rapidly taking my foot off the gas and then putting it back on. When I pulled over that time the engine cut off when I took it out of gear. When trying to restart the engine was turning over very rapidly and I had to pump the gas pedal to get it to start up. Also this time the engine was overheating with the needle just below the red almost on the line between black & red

Is this possibly a fuel pump problem or more likely a sensor? I checked the manual last night and the throttle position sensor sounds like it might do this.

What do you guys think?