I have screached this topic on here and have found a few leads, it just seems that everybody has had a different fix. I have factory manuals on the way but I don't have any pics of where the IAC sensor is or the vacum line boot that rots or many of the other suggestions. My truck did a intermittent stall a couple of times, you would be accerating and around 50 the rpm would drop to 0 for about 2 seconds and the engine light would come on, the first couple of times it came back to life after the 2 seconds check engine light would go off and everything would go back to normal. Well today it totally died on me 5 times in a row at various speeds. I would shift to neutral and the truck would restart right away. I went to autozone to get the codes read and there were none stored. I even rented the tool to read them because I figured it would happen again on the way home, well no such luck. Any pictures or other suggestions would be greatly helpful. The truck has a brand new fuel pump and fuel pump relay with in the last two weeks.

Thanks everybody

P.S. I feel like a newbie all over again, I normally spend time in the 7.3 Powerstroke forum and can actually help other people with there problems, but now I feel like I am starting all over again.

 

Is this the truck you just bought? I don't have an answer, just curious.

 

I was going to go out and take pics for you but my lovely girlfriend decided she needed the camera more than me today. anyways if memory serves me correctly the IAC is on the back side of the upper intake

 

Yep, didn't do it once during the test drive or the two hour drive home.

 

I suggest that you check all of the vacuum lines and especially the larger ones related to the PCV system and the EGR system for startrers. The large 90* rubber ells are notorious for going bad in the "V" portion.

 

Update.... I drove the truck home from my moms house(20 min) and about half way home the truck started stuffering like it was missing or something like that. Was bogged down and have very little power after that. Do I have coil packs going out too? Or do you guys think this is all related. I am thinking about taking it to the stealership and seeing what they can diaganoise. These parts are to expensive to part changing.

 

Try Autozone or Advance auto parts to get the codes pulled, it's free and we can decipher the info to help. It sucks to buy a nice truck and have problems immediately.

 

No codes stored, I stopped and had them scan it and rented the scan tool myself to see if it would have one later. Check engine light only comes on when motor dies or stalls for the 2 seconds, goes off right after I get back power or right after I start it again.

 

Neither the IAC or the elbow are you problem. From your description, the first thing you need to check is fuel pressure. If it's around 50 PSI the fuel pump is okay and your ASD relay likely needs replacing. But sometimes you'll get a lean code with a weak pump and that's not happening. Right now I'm going with an 80% chance it's the ASD relay.

 

You do now:

IAC pictures: https://www.ford-trucks.com/forums/9...4l-triton.html

PCV vacuum hose: 1998 Ford Expedition Vacuum Assembly

 

Thanks for the pictures alloro. The guy I bought the truck from said he just replaced the fuel filter, fuel pump, and the fuel pump relay. Are any of these the parts you are talking about? If not what does ASD relay stand for? And how do I check the fuel pressure, do I check this on the fuel rail?

 

Yes, those items you mentioned all can stop the engine from running. That's why I suggested to first check for fuel pressure. You do check for pressure on the fuel rail using a gauge.

ASD=Auto Shut Down relay. This relay goes on and off with the key and it's function is to power the ignition, injectors, and basically any engine electrical.

 

Alright, I will try to do that thursday, I have to work my 24 hour shift tomorrow. What pressure numbers am I looking for?

 

General Specifications Item Specifications

Fuel Pressure
Engine Running kPa (psi) 193-310 (28-45)
Key On Engine Off kPa (psi) 242-310 (35-45)

These figures are from my service manual, I hope it helps.

 

Alright I bought a fuel pressure guage and went to check the fuel pressure and can't find the hook up fitting, I remember it was on the front passenger side on my 4.6 but I can't find anything on this 5.4. Is it in a different location on the 5.4?