Cannot get my obs started, what am i missing...

ghohouston · Oct 7, 2014

as many of you may know, i am a fleet mechanic for a company with over 400 powerstrokes, and am beyond familiar with them.

Now, to my 97. My ignition was broken, and long story short, ignition was left on overnight. Truck was dead next day of course, used my 6.0 work truck to jump it off. It took some cranking, but finally started. Ran bad, then died.

Facts:
Checked all fuses, and double checked them. All were good.

ipr is at 15% duty cycle koeo, maxes out at 65% while cranking, reaching
3000 psi icp while cranking, and cranked with icp unplugged, no change.

oil level physically checked, and have oil pressure on the dash(duh)

cps swapped out with brand new ford unit, no contact marks on old sensor
cranking rpm's show on tach, and verified on scanner

buzz test passes, and all 8 buzz loud and clear

removed chip, and re installed pcm, still no start

WAS throwing po603 and 605, which is expected, i swapped batteries with my work truck, and it does have a gearhead chip. i am not getting any codes now.

i currently do not have a fuel pressure gauge, and i have a super duty fuel bowl/hpop res/fuel pump, so no schrader valve anymore. however, if i open the drain valve with the key on, it certainly appears to have good pressure, but i do understand this is not a good way to determine fuel pressure.

I have gotten the truck started several times since, but only runs a few seconds, and very poorly at that. then dies. i tried flooring it for the hell of it last time i got it started, and it wouldnt go above 2,000 rpm's.

Im getting frustrated with this thing. It's always my own vehicles that have the most god awful issues. So if anyone has suggestions, please send them my way.

My only theory is i seriously damaged the fuel pump leaving the key on overnight, and not having the pump wired where it cuts off after x amount of time, and (dont kill me guys, i never drive this thing, but its not fused yet either). Other thought was maybe uvch, but it buzzes fine every time

PSDEng · Oct 8, 2014

Sounds like your pump is pumping fuel just fine with the key on, but just for laughs put your hand on it and see if it's getting super hot. That'd tell you if your pump was bad.

Magnum PD · Oct 8, 2014

Weird. Don't sound easy.

ghohouston · Oct 8, 2014

bump. the pump didnt get hot the other day when i put hands on it

Patrick Feeley · Oct 8, 2014

Any way you can get a gauge on there to measure fuel pressure? The numbers for both ICP and DC% seem high for just cranking to start (especially ICP). While cranking, DC% is less than 30% typically with no leaks and engine starts. 65% is max command with no start. Cheers!

bluedge8 · Oct 8, 2014

your going to need a fuel pressure gauge on it, have to rule out fuel or keep going down that path.

ghohouston · Oct 8, 2014

thats gonna be my next step. i need to buy a fuel pressure tester. never had to buy one before, shop always had one, but now im a field mechanic. i assume harbor freight or somewhere like that would have the means of making one up?

and i was thinking 65 was on up there for duty cycle while cranking. i suppose what you're getting at is if the truck has poor, or no fuel pressure, it ramps up the icp to try to combat the issue? what about the dc being at 15 percent koeo, is that normal? i work on these trucks less and less now, so everything i used to know by heart is getting faint. from what i do remember, my 2002 7.3 would idle around 12% duty cycle.

ive been wondering if the ipr could be the issue. been contemplating just pulling it to disassemble and clean up.

backwoodsboy · Oct 8, 2014

KOEO IPR duty cycle defaults to 14.8%
After 15[?] seconds of crank no start IPR duty cycle will default to 65% and ICP will default to 3000 psi. It should also trigger a P1211 code at this point.

mattymx · Oct 11, 2014

When you're trying to start it, is there anything coming out of the exhaust? Nothing will mean either the injectors are not firing, no oil pressure to the injectors or no fuel. Is there fuel in the bowl?

ghohouston · Oct 11, 2014

mattymx said:
When you're trying to start it, is there anything coming out of the exhaust? Nothing will mean either the injectors are not firing, no oil pressure to the injectors or no fuel. Is there fuel in the bowl?

if you would have read what i posted, the bowl is full, and if i open the drain valve with the key on (e fuel) it definitely has some pressure behind it. as far as oil pressure, im getting 3,000 psi icp while cranking. i am leaning more towards the fuel pump being toast.
and yes, i do get some smoke while cranking.

mattymx · Oct 11, 2014

ghohouston said:
if you would have read what i posted, the bowl is full, and if i open the drain valve with the key on (e fuel) it definitely has some pressure behind it. as far as oil pressure, im getting 3,000 psi icp while cranking. i am leaning more towards the fuel pump being toast.
and yes, i do get some smoke while cranking.

Yes I did read your post and no you didn't say the bowl was full. You said that you opened the drain and it seemed like you had pressure. Not quite the same thing. But anyways, good luck.

Bustedknuckles · Oct 11, 2014

Throw a IDM in it and see what happens. I had one acting just like that, no start and everything checked OK and it was a bad IDM.

ghohouston · Oct 11, 2014

i know it possible, but it buzzes fine, has NO codes relating to idm, and ran fine before key was left on. on top of that, the idm was replaced about 4 years ago, and the truck was parked after that, so the idm basically has less than 1000 miles on it. i really am thinking its the fuel pump at this point.

Bustedknuckles · Oct 11, 2014

ghohouston said:
i know it possible, but it buzzes fine, has NO codes relating to idm, and ran fine before key was left on. on top of that, the idm was replaced about 4 years ago, and the truck was parked after that, so the idm basically has less than 1000 miles on it. i really am thinking its the fuel pump at this point.

The one I was working on buzzed fine too. I found it by amp clamping the injector wiring and figured out that they weren't actually being fired. You could hit it with a little ether to see if its a fuel issue.

ghohouston · Oct 13, 2014

Well guys, i got it figured out today. Like i stated before, its like i loose all common sense when i work on my personal vehicles.

Opened the drain valve again, with the key on, fuel still shot out with authority, however, something told me to remove the lid, and see how full the bowl actually was, which for some reason i didn't do before. Sure enough, the damn thing was almost empty, yet the pump still sounded normal. At this point, i went and filled 2 5 gallon diesel cans up, put em in the front tank, cycled the key, and after a second, sure enough, we had fuel!

Guess i finally fell victim to the pickup foot on the sending unit falling off.

bluedge8 · Oct 13, 2014

That happened to me, except I was going down the freeway,,,, with a 1/4 tank of fuel, she just quit.

ghohouston · Oct 13, 2014

bluedge8 said:
That happened to me, except I was going down the freeway,,,, with a 1/4 tank of fuel, she just quit.

I ALWAYS see people suggesting it, and i often suggest it to people on here with symptoms similar. What threw me off was the truck ran PERFECT the night before i left the key on, but the more i think about it, it add's up. One of the small bolt holes for the fuel drain valve is stripped on my bowl, so it has a tiny leak, but im sure after hours and hours of the pump running, it ran enough of it out, where my tank got low enough.