I have a 99 F350, v10, 4x4, dually, and at a light exceleration, it seems to surge. Someone suggested faulty EGR valve. Does anyone have experience with this? My truck has 304,000 miles and pulls good and idles fine.

 

Fuel filter maybe???

 

Clean the MAF, change the fuel filter, and check for vacuum leaks.

Does it idle perfectly, especially when you turn the AC on and off?

A surge under light acceleration caused by an EGR valve usually means the mixture is off, or you have a vacuum leak or something throwing the mix off. If it were the EGR valve stuck open, it wouldn't idle right, I don't think.

 

Any plugs hissing or loose?

 

Wow, 304,000 miles you say.

 

What is a MAF? And yes, that 304,000 is correct and have pulled a 5th wheel for 50,000 miles of that.

 

Mass Air Flow sensor. It senses how much air is going into the motor.

It's inside the air box, after the air cleaner. If you separate the two halves of the air box, it's in the rear half. Looking at the rear half of the box, use a screwdriver in the slots to pry up the plate and the MAF is in there.

It can definitely do what you describe.

 

Be VERY careful cleaning the MAF. The tiny wires can be broken easily. To clean it use a MAF cleaner on a Q-tip. Wipe the wires carefully and let dry then put it all back together.

 

Actually, the older GM MAFs were pretty easy to break. All the Ford MAFs I've seen from '96 onward are pretty sturdy, the wires are stiff, the filaments themselves are encased in a glass bead.

Not that that means you shouldn't be careful, but it's not brain surgery

 

Thanks for your help, everyone. I'll check this out in a couple of days and let you know.

 

O'k, I think I shot myself in the foot some time back. When I opened the air filter housing to work on the MAF, it occured to me that the "Tornado" I installed a while back was installed right in front of the MAF. Thinking the position may have messed up the air flow over the MAF, I moved it down stream of the MAF and did a test drive. No surge at any throttle position or speed.

I went ahead and cleaned the MAF, since it hadn't been cleane in 304k miles, then did another test run of about 15 miles in town and out. No surge.

Hope this turns out to be this simple and thanks everyone!!!!!!!!!!!!1