Last night on the way home the service engine soon light came on, all seemed fine for the rest of the trip home. When I went to start the truck this morning the engine surges from 200 - 1500 RPM’s and will die off. If I hold down the accelerator down slightly it will run without surging but as soon as I go to idle the truck goes crazy again. If I try and put it in gear in dies. Any ideas?

Thanks


F150
2002
4.6
68000 miles

 

I went to advance auto and they ran a scan for me, here's the code the computer came us.


P0102
MAF or VAF
A Circuit Low Input

P0113
IAT Sensor 1
Circuit High Input

P0443
EVAP Emission
Control System
Purge Valve C fault

I have no idea where to start to repair this problem. Hate to take the truck to the dealer and pay out the butt for something that I might be able to fix. If anyone has an idea where I should start it would be greatly appreciated.

 

You have a wiring issue. Check the wiring harness that is around the intake snorkel. The MAF and the IAT are running off of it.

 

If I disconnect the MAF should the problem stop? I looked at the MAF sensor and it looks like one of the small wires is missing, could this be the problem with the idle?

 

I wouldn't think the problem would stop until you REPLACED a broken MAF.

 

you have a broken wire in the m.a.f senser itself???. gonna have to replace it. the truck wont run without it.

 

Okay changed the MAF and the surging is gone, however I still have the service engine soon light. Checked the computer at Advanced Auto and got this code P0443 EVAP Emission Control System Purge Valve C Fault.

Guys any idea what this is and where it is located on the truck?

Thanks

 

pick up a haynes manual,it explains evereything. im not to familiar with the every part of the system. alot of times its a cracked hose or something like that.

 

Did you disconnect the neg terminal on the battery when you changed the MAF?

If not then do that for about 30 minutes, it'll reset your pcm and clear the check engine light. If there's a real code still to be checked then the CEL will come back on and you can address whatever the codes show.

 

I just seen 4six MAFs pretty cheap over at Global Auto

Good luck.