I have a 1999 F250 Super Duty With the triton V10.
It just out of the blue started having a hard time idleing. When i start it, it bounches between 400 and 1300 rpms. It surges really bad. When I drive it and I slow down to a stop or turn it wants to die out. Also when I am at an intersection it is a little better in park than in gear. I can't put it in reverse without it killing and then have to gas it to move.

I went to Autozone to have them read the codes and it said my MAF sensor was bad. I changed that out along with a new air filter while I was in there and it still does the same thing.

What should I try next? TPS, IAC? Anyone else have this issue in the past? I hate to have to keep buying parts that don't fix the problem.

 

Something you can try.
While idling , unplug the MAF sensor. If the idle settles down, the MAF is defective.

 

Like I said I already installed a new MAF Sensor. But I went out and tried it again anyways. I'm still getting the exact same surging. Thanks though.

 

Not knowing where you purchased the replacement MAF sensor is why I suggested taking it out of the system. Just because it is new is no guarantee it's good ,ESPECIALLY, if it's not OEM. It is a very common problem with imported aftermarket parts these days.

 

Thanks for the info. Nice to keep in the back of my head. I did find the problem. I had a cracked vacuum hose that connects under the trottle body. Now I just need to find one. Autozone didn't carry one. They tried to sell me a heater hose but it wont make the bend without pinching. I guess I will have to check with the ford dealer.