hey everyone, i've been working on my truck for months now on and off. i thought i finally had it back (thanks to some help here), but i have (again) problems with running. it basically only ran for a full day (hauling trip) after getting it back up and running. next day, it died on me on the road.

the new deal right now is that i can make the truck start and it will run, but it has little "hiccups" or misfires that will happen every now and then.
once it gets warm enough, the idling sounds chopped (best way i can explain it). after "chopping" it will then run fine (until the next chop). then it seems that once the truck gets warm it just stalls out.when that happens (shutting off) i can't get it to start right away. i have to wait awhile before it'll start and that lasts only so long.

the truck puffs a tiny bit of white smoke. not constant but more like a "puh - puh - puh"

I've changed out quite a bit of used up parts now...

Turbo
Injectors & wiring harness
valve seals
IDM
ICP
IPR
CPS
MAP
fuel pump
vacuum pump
glow plug relay
starter relay

all the sensors are OEM.

there's fuel in the fuel bowl, and the filter is clean.
plenty of oil in HPOP & oil level in crankcase is good.
have plenty of fuel.

Air filter is clean and fine.

no codes. no lights.

2001 f350 7.3 320k on it.

please help.

 

I'm thinking that shotgun approach is wrong.
You need to log some data to see what is going on.

 

Karlow, yea it was late last night, but i wanted to throw it out and see if there was already some ideas.

ran a scan this morning.

ignition on:

map - 14.1
ipr - 14.84%
ebp 14.0 psi

found there is a scan for oil temp? did it just for fun
eot - 80 F

cranked the truck:

icp 21.5 psi
ipr 14.84%
ebpa 13.9 psi
map 13.9 psi
epr 0.00% ( ? shouldn't it have something?)
cam status ok

even though i don't have the light on for error codes on the dash, did run that on the scanner and it pulled up codes!?

P1212
P0340
P1211
P1280

it says there's a injector control pressure failure. i have changed the IPR & the ICP very recently and it's OEM. what's going on here.

i've been meaning to see if there is a chart or something of the sort that list the proper specs for all the data scanning you can do. because on this, i really have no idea what's considered "good" or "bad".

 

Try disconnecting the ICP. It should run with it disconnected.
It says you have no pressure that ICP reading should be over 500 psig.
If that sensor is not working, disconnecting it should get you on the rode.
It that does not work go back the IPR, make sure it's plugged in with the nut non the back. I have a trace from my truck the IPR is about 10% at idle about 500 psig
At 16% I see 780 psig. You should see something in that ball park.

 

That ICP pressure is WAY low. I believe you need 500 PSI to even fire the injectors. Try unplugging your ICP sensor and re cranking. Your computer should give it a default mapping PSI of approx 2,000 which should start it barring any other issues. If it does start, you need to replace your ICP. Also, you may want to
find a thread talking about the CPS. Im not the guy to talk much detail but I've read about the replacement CPS sensors having issues. Im sure somebody with more detailed knowledge about that can chime in.

 

okay.
truck doesn't start when removing the ICP. what's strange is that when unplugged i do get around 2,100 psi under crank. the IPR went at 30psi.

i then plugged it back (icp) and recorded again. this time the ICP got "higher" results plugged, getting anywhere from 1,500 all the way down to 180 (it dropped quickly and kept changing)
the IPR kept at 14.84% with that test.

also, i took a look again at the error codes. if i keep the ICP plugged in, i get the same list of codes

P1212
P0340
P1211
P1280

if i unplug the ICP and check for codes again, i just get one code, which is the P1280.

not sure. neither one really match up with what ya'll said it ought to be.

but, the IPR is installed great, the nut in the back is on.

yea, i know the CPS can cause a no start, i would have to search on the site. for sure if that's the case, it wasn't faulty straight out of the box.
i drove with it working.

 

No, When the ICP is not installed, the system runs on a default setting so the ICP reading is BS. I would drain the HPOP, pull the IPR take it apart and clean it, and measure the resistance of the coil. I'm not sure why the IPR duty cycle does not continue to increase. The way it should work is the pressure should be about 500 psi at startup with a duty cycle of around 10% based on my truck. If the pressure as measured from the ICP is too low the computer should push up the duty cycle of the ipr until it get about 500 psi then she will start. For this to happen, the HPOP needs oil from the LPOP. It needs RPM and it needs the FI system not too leak. It could be that it will not push past 14% to get it to fire I'm not sure. You need to look up the codes to see what its saying.

 

Karlow, thx for your input on this again!

well, since i've last come on here, i made a find today that seems to be getting closer to the mark.
realized that i'm spending all my time obsessing about sensors and pressure, that i never thought to take a look at what she's doing at the exhaust (while cranking). and whaddya know. no smoke. so went again to fuel bowl and checked pressure. 30 psi. i'm going to get the rebuild kit for the fuel pressure regulator, it's getting on the old side (looking it) and it may not be working properly anymore. (o ring and spring) there's a sound that shouldn't be there. sounds like air coming in somewhere. i've scratched off the fuel tank as being a problem or the line coming from there. no bubbles in the fuel bowl and it fills up good. so my bet is on the regulator or the line going to the injectors.
if i play with emptying and filling the bowl i can make the truck start for that long. then the air comes in and it stalls.

thinking i'm on to something here.

 

Is the fuel pump original?

 

no, i had already changed it this year...it shouldn't be dying on me now...

i've put in the kit, and i definitely needed it. the spring was pathetic compared to the new one & the ring was quite worn. still not fixed though, still air coming in from somewhere.

i've listened to the pump, and while it's working, there is a noise that sounds like maybe it's mixing in air. is it possible to test for psi at the fuel pump? i'm thinking of hooking a hose to the fuel pump and checking with a gauge. would that tell me anything. what psi should i expect from it? same as the at the fuel bowl or +/-?

from what i can tell, it's either air is coming in from tank to the pump, or it's pump to the bowl.

 

Update.

i now have fuel pressure at the bowl. a good 60-65 psi. but...still no start!
i don't know what to do anymore, i've been at it, and at it, and still no results. all those sensors are brand spanking new. from ford. unplugging the icp for the hell of it makes no difference, and the icp is not covered in oil.

for the fuel, i'm not sure what's going on. there is fuel in the fuel bowl, it fills up fast and smooth, good pressure, but under crank i only get smoke now and then like some tease. once in a blue moon the truck acts like it wants to starts! but then it's gone, and no show.

the voltage on the batteries are great. 13 volts, more then enough to crank.
tach for rpm moves, and i have plenty to start.

i know that it can be injectors not firing, but my injectors are new, barely seen any mileage on them. they've been installed properly. the uvch is new on both sides.

i've been through the fuel tank. clean as a whistle, so what would be the odds of having a clogged fuel line going from the fuel bowl to the injectors?
the filter inside the tank is clean.

after all i've changed and gone through what more can there be? i need this truck to run, and i'm getting desperate enough to get kicked at some mechanic. well, not even the mechanic i contacted wants to see my truck after hearing what i've done!

the Ipr is new, it's installed correctly. the tin nut is fine. it's barely been used, i don't have sludge in my oil.

i don't find anything unplugged, electrical wires used up or anything like that.

but when i run the scanner, nothing is still acting like it should!

under crank

icp 82-1500 psi
icp 36 %
Ipr 64%
Map 14.1 psi
battery 13 volts.

no codes anymore. the ones that were there from last time aren't there, so all clear on that.
plenty of oil and fuel.

what now?

 

Your ICP to IPR colleration seems to be a little whacky. However, I've seen stranger and it starts and both of those parts being new, I wouldn't be quick to say that's your problem. I normally don't jump,right to these following issues because it's usually something simpler but due to the amount of parts swapping you have done, maybe we need to go deeper.
So here's deeper:

1: Compression
Have you performed any type of compression test on it? I know you mentioned your TAC moved while cranking which is a sign of compression, however how much compression? Could you possibly have a stuck or burnt valve causing loss of compression?

2: Valve Cover Plug
Have you pulled your glow plug/injector harness and tested each individual connector to make sure each injector is able to fire? Ohm out each injector on the connection by removing each 9pin connector located at the center of each valve cover. Once it's removed you can test the (front to back) 3rd, 4th, 6th, & 7th pin against the center 5th pin for resistance. It should ohm out to less than 2 ohms. Also, check the overall condition of the plug in. They are known to melt and have issues. You find the updated plug anywhere online.

3: IDM
Have you tested the IDM? If so, how did you test it? I ask this because I've seen them go back and not 100% sure there's a way to test them to see. (Somebody please chime in if I am not correct).

 

Do you get the wait to start light?

 

thanks for coming on here!
i don't have what it takes to do a compression test, so i have no way of knowing...
the uvch is brand new, and the plug isn't melted or anything. i don't know how to test for ohm on this either.

no, haven't tested the idm, don't know how, i just went and bought it. i do know that when i had changed the idm, the truck was running.

yes.

i've been exploring some more on the truck.
pretty sure it's still something to do with fuel or something in that department.
for whatever reason, one time i will get that 60-65 psi, and other times it drops to like 30-40psi and won't move an inch. since my last post here, i did have that 65 psi, but i lost it this afternoon.

i know for a fact that the main line (for fuel) is good. i changed out the lines, and the fuel pump is working like a champ. there is no bubbles at all in the fuel bowl.

but i still can't keep a consistent fuel pressure.
i found out that if you plug the return line to the tank, and turn the key on, i finally get right away that 65 psi pressure. (don't do that for long, or it'll damage something)
why is that? i had gotten a rebuild kit for the fuel pressure regulator last week, but i took a look at it today just in case. it's clean as can be nothing wrong or messed up.

something seems to be triggering something out of time, the fuel pressure regulator seems to be always returning the fuel back to the tank non-stop. (tested by holding the return line in a fuel jug and turning key on)

do you have any idea what could be causing this? why would plugging the return line give the pressure, and when not doing that, get an inconsistent psi for fuel?

so of course, i've been unable to get the truck to start, and still getting smoke only now and then.

 

more points to consider.

- shimming the FPR (even though it's a brand new oem) makes no difference.
- getting back in the fuel tank and checking the filters in there was also for nothing. for as long as i've had the truck now, i'm guess i'm doing pretty good. clean fuel bowl, tank, and the little filters inside the tank. there was a speck or two of stuff on each. nothing at all to makes even the slightest glitch. they were 99.99% clean.

-why, why why, when the fuel bowl is open, there's great flow, no bubbles.
BUT
- when closed, you can hear gurgling in the return line through the FPR??

all this, still at 30psi. won't budge, truck tried to cough to life 2 times today, but just can't. until that pressure goes up at the bowl, i'll never have it right at the injectors (as the pressure drops by the time it reaches the injectors)

i'm not even gonna bother with the lines going to the injectors. seeing how the bowl, tank, and filters look, it'll be a waste of time. seen the insides of the truck so many times now, i could have made it start million times over with the kind of pressure i'm having right now.