nHowdy guys. I just registered tonight. I've read quite a few posts , but now I'm hoping to get some help for a problem I'm experiencing. I have a 2000 F-250 7.3 psd with an automatic. It has 38000 original miles. I have what I'm calling an intermitent surge between 1300 and 1600 rpm It's not a sharp miss but feels like you're moving the pedal back and forth. I had it in the shop last week and they couldn't find any codes. They suggested I change the EPB which I did and I still have the surging. This is not a constant problem but happens when the air temp is cold, and after it has set for a while. It doesn't die , just surges. The dealer also reflashed my computer to the newest setting. Now it seems to take just a little longer to start. Here are a couple scenarios. I let the truck warm up completely when the air temp is cold it will surge for a couple blocks then clear up. If the air temp is warmer it dosen't surge. Today the air temp was in the low 30's, I didn't let the truck warm up completely and it didn't surge. I drove a bout 1/2 mile and shut it off. It sat for an hour, when I restarted it I drove about 1/4 mile and it started surgeing. I've changed the oil and changed the fuel filter about 1500 miles ago. Any help would be greatly appreciated

 

Not sure what they had you replace but describe your "Surge". Does it just take off or is it when you step on the pedal you don't get the power response?

 

They had me replace the exhaust back pressure sensor. The surge is only between 1300 and 1600 rpm. The initial throttle resonce is fine, once I reach that rpm the truck surges as if I were moving the peddle back and forth. Some times it feel like it wants to accelerate.

 

38,000 mile's? wow how do you manage to have such low miles on a 2000. It must have sat for a while....that could be your problem or be contributing to it.

 

That kinda sounds like a throttle position sensor which is part of the pedal assembly but temps usually dont have an effect on it when it starts going out. Next time it happens set the cruise control and see if it stops the surging.

 

Does it do this when you are towing or hauling a load?

 

I've only had the truck for a month and a half. I bought it from an old guy that rarley drove it. I haven't had the opportunity to haul with it yet. Power is great and hard acceleration is fine also. Mileage is 18.3 hwy ,16.1 combined. Since they reflashed the computer it seems to take a litte more cranking to start and has started and immediatly died 3 times. I don't know it thats related to the surge.
Amiller93, I thought of that because that went out on my 97. I'll try the cruise in the morning. It may or may not be temp related , but it's been colder the heck here
Thanks

 

Thats great it has low miles, but its not so great either these motors are ment to be worked not garaged. Well I hope you figure out whats causeing the problem but in the mean time you need to open that sucker up and blow all the cobweb's out .

 

Mine does this when warm and also with cruise on..

 

It didn't surge ysterday. Today it sat on the job all day then when I started driving it was surging at 1600 rpm. I tried the cruise and it still surged. Once it warms up the surging goes away.
Wes

 

Well the pinpoint test really dont pinpoint anything, they check just about everything.
One thing that does kinda jump out as being "Cold" related is the FPR oring and spring possibly sticking.

If you want PM me your email address and I'll send you the complete pinpoint.

 

OK I've really paid attention to these symptoms. If I start the engine and don't let it warm up completly and drive off it won't surge until it warms up to operating temp. Then it will surge between the range of 1300 to 1600. This is intermitent, there are times that it will run smooth. At times there is also a different sound to the injectors in the same rpm range. I can only feel the surging at lower speeds, when the speed is around 35 to 40 mph in third gear. At higher speeds and in overdrive I don't feel it.
Thanks
Wes