PigPen

[PigPen]

Yes, the black smoke was just from trying too much.

What about the smoke escaping from the turbo?

Also, no codes are present. Just checked now.

Robin, you are correct, this is the type of learning that makes your head hurt.

[cadillackid]

smoke from the turbo is likely a small exhaust leak... putting smoke in the pipes tends to escape any little place it can. usually around one of the Vband clamps...

have you verified the glow plug relay good? or assume so because the battery voltage changed while the key was on?
-Christopher

[PigPen]

I still have to check. I lent out my meter so was waiting on it all day. Have it now, but I'm not at the bus anymore (it's at a relative's house nearby that has more room).

My plan was to go check in the morning. What all should I check?

I reread what you said about the terminals and understand that now, but let's say the power at both terminals is correct. This doesn't mean that the glow plugs are working, just that the relay is, right?

Would the next step be pulling each plug and testing resistance of each individually?

[roach711]

Leaky up pipes are fairly common on the 7.3L. If you're seeing smoke coming from the gap between the "Y" adapter at the turbo and the two up pipes (the pipes coming up from the exhaust manifolds to the turbo inlet) then the donut seals are leaking.

You can cheaply replace the seals but they tend to start leaking again fairly quickly. The best fix is to install a set of bellowed up pipes which seal better and don't leak after a short while.

The original starter on the 7.3 is pretty wimpy. When cold starting mine sounds like the batteries are low even when fully charged. New high torque starters are available that spin the engine over way faster. I'm considering one for mine.

[roach711]

Have you replaced the filter in the fuel bowl? The fuel bowl is to the right of the glow plug relay in the picture Cadillac shared. If that filter gets plugged everything comes to a halt.

How old is the fuel? Diesel isn't as sensitive to age as gasoline but really old diesel may be a problem.

Your 2003 has an electric fuel pump located on the frame rail just below the driver's seat. When you turn the key to "accessory" you should hear a hum from down there.

There are two strainers on the fuel pickup in the tank. At 100,000 miles mine were clogged enough that I was blowing a lot of white smoke when driving. To disconnect the fuel lines you'll need some Ford quick release tools but fortunately they're pretty cheap at most any parts store. Cleaning the strainers is simple.

Does your 7.3 have an engine heater? Look in the front bumper for a three prong electrical plug. That will be the engine heater connector. Try plugging it in for a few hours and see if the engine warms up. A warm engine will at least negate the need for glow plugs.

[cowlitzcoach]

I think everything you need to know about starting a 7.3L has been said.

One thing I learned is that it won't start if the power to the pump is disconnected.

On one of my 7.3L's I was chasing a hard start issue which I finally determined was six of the eight glow plugs were dead. I replaced all eight and I still had a hard starting issue. Come to find out in all of my messing around I had knocked off the signal wire that powered up the shut off valve--no power, no fuel.

Since you are getting smoke I would say it isn't a fueling issue.

At this point I would lean toward the glow plugs are cycling but not enough of them are still alive. You can start a 7.3L with as few as three glow plugs if the ambient isn't much below 50* but it won't be an easy start. You really need at least six of them warming things up.

After all of the no starts you have had you are also running the real risk of having fuel go past the rings and cleaning the cylinder walls, pistons, and rings enough that you will be losing some compression as the rings will not seal against the cylinder walls as tightly any longer.

I would echo the sentiment of plugging in the electric engine pre-heater and get it nice and warmed up. With the block all warmed up it might not require very much glow plug heat to get started again.

If you get the bus started by plugging it in you will know for sure that you have some glow plugs no longer doing their job.

If you don't it may be due to a combination of glow plugs not working, washed cylinders with lower compression, and still not enough heat from the engine pre-heater.

It can be very frustrating and aggravating particularly when after you get things going you realize your dump mistake had you chasing your tails for however long it has been.

Good luck and keep us posted as to your progress.

[PigPen]

Chris, Roach, Cowlitz, and everyone else... I just want to reiterate how grateful I am for all the input on this problem.

As far as the up pipes go, that is good to know. I have seen you discussing replacing them with the bellows style before and it is on my radar to do.

I also like the idea of a new, high-torque starter, regardless of if it is the problem now or not. I may order one of those and a new CPS. The CPS would be nice just to have in the glove box, as I understand they go relatively easily and quickly.

Yes, the fuel filter has just been replaced as I was trouble shooting. All good there. I have not checked the in tank 'socks', but at this point my plan is to address all non-fuel related suspects first. The fuel isn't that old, and I'm getting plenty of signs that suggest the fuel is making it to the engine. I listen to the pump run every time I turn the key. It always finished before the glow plugs do, so I hear it run its cycle in full too. Combined with the fact that I'm getting black smoke towards the end of multiple starting attempts is enough for me to move fuel stuff to last on my list.

I can't believe I didn't think of the block heater. Okay, I should be honest: I can't believe I didn't know I had a block heater. I know they were an option on these 'vans' and assumed that I didn't have one. But I just looked it up, and the weird assembly and wire coming of the block above the oil filter that I've been curiously looking at for the last 10 months suddenly makes sense

Today I'll be working on getting that plugged in, testing the glow plugs, and probably a lot of this:

[PigPen]

The beast lives!!!

[cadillackid]

what did you do? plug in the block heater?
-Christopher

[PigPen]

Yes.

The glow plugs are getting power, but I haven't figured out exactly how to test them yet. I'm guessing I'll find that most are bad. Is that a safe guess?

[cadillackid]

sure sounds like its possible.. whats the weather like where you are? is it cold? I have started my 444E before on 75 degree days without using the glowplugs (just plain forgot) and it would swing a little longer but would start
-Christopher

[PigPen]

The weather was about 70 today. After getting it to start that first time, it started immediately the rest of the day. We were able to complete the coolant flush and take it out for a drive tonight.

Tomorrow we will begin testing glow plugs individually.

It felt good to drive the bus. But it also reminded me that I have more problems to deal with.

This thing does not like accelerating, especially when first starting. I'm no expert, but it feels like the engine is responsive to the throttle being pushed. There is only a problem at low speeds. Perhaps a problem getting from 1st to 2nd, but I had a hard time telling for sure tonight.

Also, it is extremely slow up hills. I turned from a red light and had to go up a fairly steep hill right away. I got stuck going 10 MPH until the grade came down a little. It was steep, but we aren't talking mountains here...

Any tips on things to check? Is there anything I can measure with a scan tool while driving to get better insight?

[cadillackid]

Hard starts and no power , don't ignore checking the fuel pressure.. you may have a weak pump or clogged screens as others mentioned...
Before testing plugs get s gauge and install it on the test port near the filter and see what you have , even brake stand it a bit to see if a bit of load pulls the pressure down..
Christopher

[PigPen]

Okay, I'll do that tomorrow then. Will any normal test kit work? What I'm asking is: can I just go grab the autozone loaner or do I need to buy something more specific?

[joeblack5]

Our 7.3 vans have a exhaust valve that is closed when the engine is cold.
This will help heating up the engine.
If it is activated the engine has very little power and also sounds like it is restricted.

I am not familiar with the 2003 version with electric fuel pump but the fuel pressure is critical for power.
The older version, (two stage mechanical fuel pump) need a fuel pressure of 55psi + and with 15 psi it will run but is hardly driveable.

Pick your poison.

Later J

[cadillackid]

I believe the PSI is 65 on the electric pump.. on the mechanical pump, the early versions were built with a 47 PSI spring, the #8 injector would bottom out at times so they produced a 72 PSI spring.. I updated mine...

so I know they will run fine on 47 PSI...

the way these engines work is there is a second oil pump that builds super high pressure.. 1000+ PSI, they use that oil PSI to multiply the fuel pressure in the injectors themselves that make the shot.. low fuel pressure results first in injectors bottoming out (im told).. really low fuel pressure results in low-fueling to the cylinders.. the computer monitors the commanded and actual High pressure oil, but doesnt monitor the High pressure fuel...

if the High pressure oil (HPOP) system is faulting the computer usually issues a code related to the ICP or IPR.. the ICP is the sensor that reads the high pressure oil - actual pressure, and the IPR is the regulator that regulates it.. so the computer watches to see if the commanded and actual are close.. if the ICP sensor goes bad then its possible that the computer "thinks" the HPOP is higher than it really is.. result - under-fueling. the only way I know to check that is to run it on a full computer scanner and watch the IPR command %..

I hadnt thought of the Exhaust Back Pressure Valve.. i dont have one ofthose on my 444E.. its a good thought though usually the engine sounds "wierd" when that sticks closed..
-Christopher

[roach711]

Glad to hear the beast is finally growling!

A stuck backpressure valve could explain the dogginess and it's fairly easy to get at to check. The linkage runs from the turbocharger pedestal to the turbo output just before the down pipe.

My pedestal was leaking oil at the linkage so I removed the valve/linkage and plugged the hole in the pedestal.

After all this you'll be fairly well versed in Powerstroke lore.

[roach711]

Your starting problem made me curious about testing the glows. Here's a post from one of the Ford forums:


"A quick check with a digital ohm meter at the Glow Plug Relay, between the large lug towards the drivers side & ground, with the key off should read 8 to 9 ohms..if all of the glow plugs are good..Also, check the voltage with the key on on a cold start, should read about 10.5 to 11 volts if the system is working properly.. You can also check each of the glow plugs individually at the valve cover connector..with the following :

GGIICIIGG
G - Glow Plug
I - Injector +
C - Injector -
Ohms between the G and block Ground should be 0.1 - 2.0 ohms.
Ohms between the I and C one at a time if one or more is > 5 ohms, it will point to the side's gasket connector or UVC harness being shorted."

Your 2003 will have one wiring harness connector on each valve cover on the valley side of the cover if memory serves. Getting at the connector to test each pin may be a chore. The older 7.3's had two connectors on top of each cover.

[PigPen]

Interesting, thanks for the information. It rained all day so I didn't get a chance to do anything. I just got over here and it started first try again after sitting overnight. Took it on another drive, definite improvement over yesterday, though still obviously sluggish.

I'm looking at the turbo now. Is this where the valve would be?



It is right in front of the clamp holding the down pipe on.

[roach711]

I think that's it. The linkage should be under the turbo in that area. Look for a rod coming out of the turbo pedestal and connecting to a lever that opens/closes the butterfly valve inside the adapter on the turbo outlet (this is all from memory). In the picture below that oily-ass rod in the center of the picture is the actuator rod.