What can be wrong?
 

I need the opionions here.........

I replaced the plugs and wires a month ago and the motor has responed well to the changes, incresed gas mileage is a plus.
I just noticed yesterday that while I was EASY accelerating from a dead stop, the motor was stuttering. As I increased the speed the stuttering disappeared . This only happened twice in a 20mi trip. My suspision is a Fuel filter, but what do I know, I am only guessing.
Other than this problem, the motor runs fine.
what do you think?
How does a bad fuel filter react?

A dirty fuel filter would restrict the flow of fuel to the engine. This would be especially noticable when there is a high demand for fuel. If it runs smoother when you accelerate heavily than it does when you accelerate easily, that would not suggest that the fuel supply to the engine is being restricted by a dirty filter. What changes between heavy and light acceleration is vacuum.

Check all around the engine for a rubber vacuum hose that is broken, disconnected, rotted, etc. Look especially at the vacuum lines that run from the throttle body to the vapor canister.

Some other things to consider from the '95 FSM section on Hesitation, Sag, Stumble.
Symptoms defined as: Momentary lack of response as the accelerator is pushed down. Can occur at all vehicle speeds. Usually most severe when first trying to make the vehicle move, as from a stop sign. May cause engine to stall if severe enough.

binding or sticking tps
oxygen sensor not grounding on threads in exhaust manifold
improper fuel pressure
EVAP canister purge for correct operation
contaminated fuel
fuel injectors
bad ignition system ground
alternator output voltage incorrect
air leak between MAF sensor and throttle body

Nick, recently Bob (echo ssei) and I both found lots of dried up vacuum lines on our 97's. Being in the climate you are I'd suspect the same.

Not sure if all these are on your engine: A couple of not easy to see culprits were the u bend to the throttle body and one right over the throttle body connecting two lines.

thanks for the quick reply's......

Let me first say that the stumble is almost non noticable when it happened, it was more of a feel than a sound and it happened very quickly then it disappeared ........

Vacuum hoses - if it was this, wouldn't it be a problem all the time and not just at off idle and it only happened twice off idle.

Not necessarily. Bob had a bad evap purge vac line..actually it was slightly cracked. He found out because only at temps over 115 it would set a SES light. The world might have been in the right position for you to notice.

Should I hook up the diagnostic tool, will there be a code if it is a vacuum problem or even if it is another problem and no sign of a Check Engine Light?

I'm not sure that the diag tool can see the air door requests and positions..

Anyone know..please chime in.

Bill/Bill - thanks again for the help, I will start looking at the vacuum hoses and go from there.
If anyone else has an opinion, please chime in please......

Nick, remember, I have the '97 FSMs if needed ;)

Nick...I told Bob to start driving ;)

He'll help ya out.