so my truck runs odd until it reaches operating temperature, while idling it sounds like there could be a miss but its not very audible or noticable, once the truck warms up a little tho it stops, and if i don't let it warm up all the way it will run weird when crusing at 45mph at 1200 rpm the truck will shudder every few seconds, if i shutoff over drive it moves the rpm to 1500 and the truck doesn't shudder,

im thinking maybe a sensor or maybe its the 500k thats on the injectors and they are finally going out, buzz test wasn't strong but it wasn't to bad , the transmission is newish less then 100k on it and it was built up to bulletproof status when it went out the last time

for the time i just let the truck warm up all the way before i go anywhere, im going to do a refresh or rebuild this summer

 

It sure sounds like injectors to me. More specifically, worn poppet seats. If you wanted to, you could pull the valve covers, remove the solenoids and solenoid spacers, then check the clearance between the armature plate and poppet body. It should be greater than .0015", at a minimum. The more clearance, the better.

 

ipr.

check the tin nut

 

check the nut for what that its tight?

 

not that it would take that long but even if it were out of clearance i don't have the shims and its time for new injectors anyways if it is the injectors then i'll just wait till the summer when i do my refresh they've ran for 500k they can run for 1-3 k more. i also have a few other known problems and its time for a refresh if not a rebuild. truck is still super reliable on the road and off, so im not to worried

 

OK. I was just throwing it out there in case you wanted to do a firm diagnosis. With 500k miles and the symptoms you listed, it's pretty likely they're worn. What happens is that as the clearance decreases, the oil between the armature plate and poppet body creates a suction that's hard for the solenoid to break. As the injectors warm up and the oil thins, the suction breaks more easily and the injector starts to operate closer to normal.

 

thankyou that is helpful and explains everything to a t i will still check the ipr nut but what your saying makes sense.

 

Finally a descent explanation to why my van shudders and shakes slightly at 70 - 80 km/h, before it reaches normal temperature

If I switch off the overdrive it runs normal.
It's hard to slowly accelerate from 70 to 80 km/h when this happens. If I step on it, it's fine.

I had Ford dealership test it, and they couldn't find the problem. But they found a slight drop in voltage to the injectors, just when it happened.