02 Grand Prix drops power

**Chuppster** · 06-08-2014

I recently purchased a 2002 Grand Prix GT with 157,000 miles on it. When you accelerate, it has plenty of power, but at times it randomly loses all power, as if I had let off the throttle entirely. Sometimes it will stay in this state for a second, sometimes two, then power returns. There doesn't seem to be a pattern for when it occurs. It happens frequently, perhaps one out of every two times I accelerate. What is the first thing I should check?

**Madness** · 06-08-2014

any check engine codes?

**QUICKSILVER462** · 06-08-2014

Start off by checking the fuel pressure at idle, and then verify that pressure is maintained under heavy load. If fuel pressure drops under load than an extreme lean condition will exist and power will drop, sometimes caused by a dirty fuel filter.

**Chuppster** · 06-09-2014

There was no check engine light, but then I plugged in an AutoZone diagnostics device. It read low input from the MAF. The MAF is plugged in. I then saw that there is a sensor plug, but no sensor to plug in to. Does anybody have any idea where this goes?
https://drive.google.com/file/d/0B50...it?usp=sharing

Unfortunatly, I don't have the tools to check fuel pressure. I would rather not get the equipment just yet.

**tomtom123** · 06-09-2014

If you have ~$160 go to Autozone and try to rent the fuel pressure kit. I did today for my car. When you take it back you should get the full amount back as well.

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**REDCRAPGP** · 06-09-2014

Or $20 and a trip to harbor freight should yield you one and you'll have it for the future.

**tomtom123** · 06-09-2014

Quicksilver, if fuel pressure is not maintained when under load, like lets say when the car is revved up real fast the pressure drops from, I'd say 43psi ish to about 34psi ish, (my 99 GTP), would you say the filter is plugging up? Or pump is bad?

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