rm9792

Car has developed a stumble, cutting out feeling on medium to hard acceleration. I had a Ford mechanic ride today with a laptop doing real time monitoring and it never showed a blip, no DTC codes either. He thought at first it might be a coil going out but it never dropped on his screen. He did say his software didnt read well over 2k rpm though. Sometimes it will stumble slightly at an even cruising speed (usually under 40). its a 2005 model model with the Eforce SC and GT500 dual pumps. Alternator has been replaced with a PA Performance model so it isnt that issue either. Suggestions? Still maybe a coil pack?

HypromanGT

If you have a handheld tuner (SCT, Diablo) and a laptop you should be able to do your own monitoring. I'm not sure if it's any better than the method the dealership is using, but not being able to monitor correctly over 2k rpms seems kind of lame; usually people are datalogging while going WOT for spark advance and A/F numbers, and would be well over 2k rpms.

Maybe if you can capture some data and report back someone can interpret and provide suggestions...

Simon1

The ford tech will be ZERO help to you. They are not trained on FI Mustang GTs and do not have a clue on what they are looking at.

A tuner needs to look at it. Someone who knows our cars.

GT John

The first thing I would look at is the obvious stuff.
1. Clean the inside of the throttle body and butterflys.
2. Check your TPS for proper operation or just replace it.
http://sbftech.com/index.php/topic,13682.0.html
3. Clean the MAF sensor.
4. Check all intake fittings, prior to the throttle body, for tightness.

Then drive the car for a few days to see if the problem is still there.

Nuke

Are you aware of the TSB for the fuel pump issue? It was very common on the '05 and '06s and a few '07's. On hard acceleration following a certain amount of time cruising, you'll experience hesitation and stumble momentarily. If that's your problem, you might be able to get the fuel pump replaced by a dealer if you stand your ground.

The TSB's are listed in a sticky in the main 2005-2010 forum.

rm9792

I have the gt500 dual pumps so is that still an issue?

rm9792

I guess i can take over to PSI in Webster. They did the tune.