Hesitation while accelerating 3000-4000 rpm range
 

My 87 has developed a slight stumble or hesitation during acceleration. This is not a turbo and I have recently changed plugs, wires and cap/rotor. I use the techron religiously with 93 octane. This problem seems to be intermittent. Im just over 62,000 miles , all belts were changed and retensioned at 59,000. Would the O2 sensor be a factor ?

Any clues would give me a starting point..

Could be the O2 sensor, Sounds like you already took care of the ignition system. I would also look at the fuel system - fuel pump pressure, pressure regulator, and maybe even the filter itself.

Hi K Wayne,

If the stumble comes when you floor it could be the WOT contact on the trottle switch is not making. Might be some sticking in the air flow flapper or the pot in it getting some bad spots. Does the stumble happen in every gear?

drew1

the stumble seems to be in the half wide open throttle range.....flooring the pedal eliminates the flat spot......or stumble...
and as far as the fuel system the only parts
that have been changed would be the fuel filter about 6 months ago........

[QUOTE]Originally posted by K Wayne:
check your coil........

if i an not mistaken the tpswitch only goes to 0 or 5 volts(kind of an on and off switch)it is not gradual...correct me on this

i had the a similar problem and it happened to be the air flow meter. i know it may be something you may not want to do but pry open the cover and check the sweep of the needle, i believe its called the potentiometer. mine had a flat spot where it was worn and i replaced it with another airflow meter and now it has consistant throttle at all rpm's. just a thought

928/944,

Yes TPS is a switch. I'm trying to find a good analog vary type for prodject I,m working on if you know of one that fits the D shaft.

drew1

K Wayne,

Since flooring it clears up the stumble, it is probably a flat spot on the pot in the air flow flapper as ASIDRAVE says.

drew1

asidrave or drew1

Should my airflow meter be failing at 62,000
miles..........these units are not cheap...if
the meter is bad do you know a good source for repair or replacement ?