First the truck is hard to start. Then when it does start it idles real rough. When it gets warmed up it seems to run fine. Last year I blew rings out on my early 99. Had a injector that was bad and it straved the cylinder until blew. I didn't catch. Not mention I had the chip turned up and had the hammer down when it blew. So instead of rebuilding it I found a used 00 7.3 put the motor in. Got it running but it was hard to start. So I checked the GP relay it was was bad so I changed it. Then it started alright. But that was summer. Now that it is cold it has been doing this. I don't know if the computer is not working with this newer motor? I took the oil temp sensor out of the old motor and put it in didn't help. I wanted to see if anyone has any ideas. Does anyone think I can get a chip made for it? I tried buying a 2000 computer but Ford changed the design late 99 and it doesn't fit. Thanks guys for any ideas.

 

I would check all the usual suspects first. Make sure all eight glow plugs are good and getting power. Just because you have a new relay means nothing. Start at the top again and work down. Also the wiring harness's inside the valve cover have a tendancy to come unplugged as time goes by. They also were routed incorrectly and the glow plug wire rubs on the push rod until the insulator wears through. Then the plug gets melted because of too much power going through it.

 

Here's some pictures of the wiring harness's.

https://www.ford-trucks.com/forums/s...d.php?t=278697

 

Well there is no white smoke at start up that is why I have ruled out the GP.

 

You're right about that.
Do you have access to a scanner?

 

Only thing I have is my tuner which will give you trouble codes. But the codes it gave me don't tell me anything. I might try it again.

 

Well, what codes are you getting. Some of us here have the knowledge and experience to explain what they mean, or if they are a side effect of a chip or possibly a side effect of what really is the problem with your truck.

 

p1670, p1247, p1248 those are the codes I am getting. Two of the codes are for the turbo. Since the turbo is bigger on the 00 motor then turbo on my early 99. It is making less boost. Plus I went from 250hp motor to a 235hp motor.

 

p1670- P1670 EF Feedback Signal Not Detected - dont know about that one?
p1247- P1247 Turbo Boost Pressure Low
p1248- P1248 Turbo Boost Pressure Not Detected


that makes me think something is wrong with the Manifold Absolute Pressure Sensor. not reading boost or detecting low boost= less fuel injected and less power. can be compared to the feeling of driving a chevy or a dodge.

 

LOL

 

I wondered about the map sensor before. I used a complete 2000 motor with early 99 computer. So I have bigger turbo and injectors that came with newer motor. I thought that would be reason for the low boost reading. What would make my truck have low boost? The other day one of the boots blew off the turbo it never did that with the old turbo.

 

There's your reason for the low boost. If you get all the boots cleaned up and installed with all the clamps on straight, you should see 20 psi minimum at WOT. It will take few seconds of WOT to get there even if things are perfect. The best way to test it is with a heavy load.

 

the p1670 is a feedback signal from the injectors to the IDM if it fails it won't affect the performance. thats about all i know about the EF signal. but i thiink as others have sqaid you have an issue with your MAP sensor. i drove my turck once with the line off the sensor and i thought i was driving IDI truck. what a dog!