I posted this over on the tractor forum, thought I'd try here, lot's of good mechanics lurking about.

Know a little about the 7.3 from diesel truck forums and talking to owners.
Know more about Cummins and Kubota diesels.

My son's friends truck would crank but not fire. They parked it in a field
and headed for their deer stands, when they came back several hours
later, crank but no fire. Owner indicates truck has been starting and
running fine for quite some time (months). We've had our first "cold snap" of the
year around here, nightime lows in the mid 20's past several nights.

They called me on the phone, I thought CPS. I know most PS owners
carry one and a 10mm deep in their glove box. They had
a friend drop off a replacement from Adavanced Auto Zone. Swapped
in the new CPS, still no joy.

I drove over to see what I could do, not much as it turned out.

Truck has approx. 300K on it, by the looks of it, a hard 300K at that.

Engine seemed to be cranking a bit slow, checked the batts with a multimeter.
The newer one read a hair above 12, the older one read about 12.3. Low, but
low enough to keep the engine from turning fast enough to fire? I normally
install matched sets of batteries when two are required. We jumped it for
a bit and tried to start it, still no luck. Cranking speed sounded about the same.

Son's friends bought the truck from a friend and has been driving it without
doing anything to it. Battery terminals need cleaned badly. I pulled the cover
off the intake and quite a bit of oil coating the area around the turbo compressor/piping.
Also appeared to be some diesel fuel puddled in a valley in the intake.

Whole engine needs a through cleaning, hate working on grimy vehicles.
Not a whole lot of room to work in there, engine compartment is full.

Tach didn't register during cranking, not sure if that is normal or not.

Wait to start light, if there is one, didn't light. Temp was in the upper 30's.
However, when you keyed the ignitiion to run there was an obvious draw down
on the battery gage. Not sure if the glow plug relay should click, I don't recall
hearing it. I'm a Cummins guy, not sure how a 97 Powerstroke is
supposed to function. I know they liked to be plugged in and can be difficult
to start when cold.

Tried to find the schrader/bleed valve on the fuel system to check for fuel,
couldn't locate it. Tried to find the high pressure oil resevoir that fires the
injectors, couldn't find it. Did check the oil, it appeared full and owner
indicated it was changed recently. Was going to pull the full filter cover
but didn't want to make the situation worse.

One more thing, they lost the retaining bolt for the CPS sensor, so they
had to just "push fit" to install. No way to use the retaining bracket held
down by the 10mm bolt. Not sure if that would make a difference, I'm
sure there is an air gap spec between the end of the CPS and the component
inside the front cover.

Any diagnostic path tips would be appreciated. Read a few forums, too
much information. Son's friend doesn't have any money. It's going to
cost him at least $100 to have the truck moved from the field to a hardtop
road and probably another 50 to get it back to his place. Truck still sitting
in the field this AM, good thing the owner recently cut his corn.

Like to help him out even though he gave us crap for wasting $30 on a CPS
which didn't get the truck running. Some people's kids.

Thanks,
Neal

 

Did they try whiffing it with starting fluid?

I know very little about the PS other than the CPS which you changed, I do believe they are sensitive to oil viscosity though, you say oil was recently changed, did they use the correct viscosity? ( I would bet they did, but ask anyway )

 

No starting fluid, was leary of the glow plugs going Boom!

Truck has been starting and running fine for months.

Need to find a replacement fastner for the CPS mount, want to eliminate that as
an issue.

Thanks,
Neal

 

Buddy whiffs his IDI 94 every day to get it to light off ( it's just about dead.....) and never a boom, I wouldn't think the PS glow plugs are any different.

Has it been starting in the cold or was this the first time out in colder weather?

If so, then you might want to check each glow plug electrically, my old Chevy 6.2 wouldn't fire when I had less than 6 glow plugs working in cold weather.

 

Check the plugs that go into the valve cover gaskets, they are known for chaffed wires and broken pins. It is a pass through plug for the injector wiring, they fail on both sides of the plug.

You should hear the glow plug relay click on initial key turn. That older year has a wait to start light on the side of the dash not in the instrument cluster like newer trucks.

High pressure pump reservoir is on the top front of the engine, probably hidden by a plastic power stroke shield.

Oil in the intake passages is normal for those engines, don't worry about that.

Fuel in the intake valley is probably from ULSD eating up dried out orings on the fuel lines at the filter housing and or leaking orings between the filter housing drain valve. You can get the fuel line orings, ( they are actually called fuel line sleeves) from an International dealer. They come in a bag of 5.

The CMP bottoms out flush to the block, it has an edge on it so you can't push it through.

Take the fuel filter out and verify fuel supply. If there is fuel in the housing it probably not a fuel delivery issue. Change the filter while your there.

Check those things a repost back, we'll try to get it straightened out.

 

Have seen a lot of glow plug relays on PSDs burn up. Once the contacts get pitted and there is some voltage drop, the condition gets worse fast and sufficient current just doesn't get to the glow plugs. The relay sits on top of the engine, have a look at the big terminals for heat damage, and see how warm the relay gets when activated. You can also measure voltage drop with a meter.

The slow cranking speed you mention may also be an issue. It may be a battery, cable, or starter problem. It may also be a belt driven component like the a/c compressor seized and causing drag.

A scanner is helpful diagnosing no-starts on these things too. You can verify the RPM signal during cranking and also verify high pressure oil is sufficient. These engines need to see a certain amount of control pressure before it will fire the injectors, I think it was minimum 500 psi during cranking. Have seen Injection Pressure Regulator valves hang up and prevent starting occasionally.

Hope this helps, none of it is guaranteed to be the problem, just more stuff for you to look at.

 

Just for giggles take a multimeter and check the negative battery terminals to the alternator housing. Should be around zero ohms.

Had a buddy with a 2005 powerstroke that had the drivers side negative battery terminal at 32 ohms.

Was causing all sorts of problems from non functioning turn signals to fuel gauges not working...

 

Are you getting any smoke out of the exhaust when cranking it over?
Can you hear the fuel pump on the drivers side frame rail running?

Power strokes can be a hard starting engine.. they must see at least 350 rpm during cranking or the HPOP will not charge enough oil pressure to fire the injectors..
Try getting a good charge on the batteries..
If memory stands correct you should see that tach jump up a little after 1 or 2 seconds of cranking... If not, 99% of the time it leads to a bad crank/cam sensor on the front cover. Seeing as how it was already replaced check wiring to that sensor and all fuses if your not getting any fuel...

 

Update, still haven't heard from the PS owner, my son can't get in touch with him (NFI). I even went out and purchased a 8mmx1.25m15mm bolt to replace the lost CPS mounting bolt. He hasn't stopped by or called to claim it, not sure he would be able to install anyhow, hopefully we will hear from him soon. From what I've read you have to be careful installing the bolt, front cover is aluminum, no telling how many CPS have been RnR'ed on this truck at 300K.

No smoke during cranking.

Nice old truck, it needs a weekend of basic maintainence and under hood cleanup. I hate trying to work on greasy equipment.

Thanks,
Neal