No problem.

Incidentally, the truck would not start cold this morning. This time I kept the scanner on it when it cranked. It's getting an RPM signal cranking at around 180 rpm, which causes the ICP to come up nicely to 2250 psig or so. I gather it is not the HPOP if it can build to that point and with those RPMs. Fuel Pulsewidth hovers in the mid-3ms range. It is reporting the glow plug solenoid correctly, and with everything in and cranking it retains a battery voltage in the mid to high ten volt range.

I've gone back to the diesel fuel supply for the moment. When I gauge it and flip the switch on, pressuresurges to around 80 psig, then drops back. One thing bothers me about this, though. Once the PCM kicks the pump relay out, I'll lose all my pressure in less than 30 seconds. That seems awful quick to me. I've been hunting for a specification for how long it is supposed to hold pressure, but have been unsuccessful.

After the cranking this morning, I did pull a P1670 out of memory. That's an EF Loop Code. Maybe the power went too low from the extended crank, so it thinks it has an open to the IDM?

Travis-
From what I am told, the fuel injectors will not fire on the truck unless it sees an RPM (Cam Sensor) signal of at least 100 rpm, and ICP reading of at least 500 psig, and a battery voltage of 10. The diesel fuel rail should be between 30 and 80 psig. I don't know if you have access to that or not, but thought it might aid in your own struggle. In the mean time, I'm going to slog through the fuel pressure checks.

 

Numbered the above.
1. that is correct
2. also correct
3. Batt voltage must be 10.5 or greater. If below 10.5 IDM will not fire.
4. correct, but as soon as the fuel pump turns off all pressure bleeds off immediatley(at the fuel bowl) Pressure is maintained in the fuel gallies in the heads by a check valve at each feed connection at the heads(Drivers front, and Pax rear.) If you are reading pressure from the test port on fuel bowl there will be no pressure upon fuel pump shutoff.

Plug in block heater and see if truck will crank, If so then the GPR reading is lying.

 

Thanks for the update, bdrummonds. I was reading the pressure at the bowl. I hooked up to the ports on the rails today, and it's all in range.

As a side note, I don't necessarily like to second guess folks, but I am very curious as to why IH decided to dead-rail the last portion of the system and put the return line at the filter. I guess they wanted each cylinder bank isolated.

I did get it to fire today with a little help from the block heater. It starts out with maybe five or six cylinders and picks up the rest within five minutes or so. I have since cleared the codes, and the P1670 hasn't returned. I also ran the Injector buzz test. Some are louder than others. We do get a buzz from all eight. I am starting to wonder, though...

 

Have you checked your wiring harness'? Under valve cover, and at valve cover? if connections are good you may be talking about a couple of injectors going bad.

 

Sounds exactly like mine....

What's it show for the CCT (cylinder contribution test)?

Mine has 310,000 on it. I recently had the #5 injector changed only because it failed the CCT. It doesn't take as long for it to run good now. But it still takes a few minutes for it to finally run "clean". It's also got new VC gaskets and UVCs. GPR and GPs are fine. No smoke on start. Never had it even when the GPR was bad.

It'll crank up and run like crap then it's just like you flip the switches to the dead injectors one by one. All of mine buzz tested fine, just one failed the CCT when cold. But my money's still on the rest of the injectors needing to be replaced. If I plug in it'll crank fine as well.

I know people on here have injectors that have gone for 500K miles without needing to be changed. I think the internals of it are shot. Maybe the cold weather is causing the poppets to bind in their bores? Either that or the solenoid on the injector is weak when cold.

It's glad to hear someone else has this problem...

 

You might try repeated buzz tests on a cold morning without the block heater. If the quiet injectors come up to the same volume as the louder injectors after repeated buzz cycles, try and start the truck then.

Injector issues make sense, but don't forget to monitor IPR % while cranking, just to make sure. The ICP readings indicate the IPR is doing it's job, but it won't hurt to check.

 

Mine was in the shop for more than a week. All that showed after repeated cold AM troubleshooting sessions was a bad #5 injector. Now that it has gotten colder it needs to go back for more cold AM troubleshooting.

I feel the #5 was part of the problem. It still runs like crap till it's warm, but it runs better faster. So #5 must've been the worst one of them all.

 

Sorry for the delay with updates. As usual, things have been a bit crazy for the run-up to Thanksgiving. One thing to be thankful for is that the truck is running fine once again.

It wound up needing injectors. Compression checked out fine. If I buzzed them enough, I could get a few more injectors up. I wound up with four that were quiet, two that were marginal, and two that were loud. You could get it to start, and as the temp came up, it would pick up more cylinders. Over this week, the temperatures dropped off about 20 degrees, and that made it even worse. So, we bit the bullet, and I made the call. We ultimately decided to do them all while we had it apart. Man, are those puppies expensive! At any rate, the truck starts and runs like a champ now. Power is way up when it's running, too. To show the new injectors some love, we changed the oil, sucked down the HPOP reservoir, and refilled it with new oil before we cranked it for the first time.

I found another problem that probably gives some insight into why the injectors let go. Once I finally got the truck inside the shop, I discovered that the fuel system had been modified at one time for a range tank. When someone took it out, they just put a section of hose where the output for the pressure pump was. Non-pressure rated fuel line, of course. I can just imagine that failing and letting air in, and by the time anyone noticed the damage was done. I had that happen to a friend's truck that was a 6.0. Nobody even noticed it until it started to leak diesel.

I also found some creative wiring on the pump that needed to be rectified. The pump mounting had also worked loose, with the fuel pump drifting toward the brake line. The clip was missing for the supply line, too. That's what I'm here for...

Have a Happy Thanksgiving, y'all, and thanks for all the pointers. They did a lot to set me in the right direction.

 

Well, good, you got it fixed.
Happy thanksgiving, too.

 

Glad it worked out for you!

Sounds exactly like my problem!!!

The temp warmed up in the last few days here, so it's doing better now. But, once it cools for good I'm going to drop it at the shop and get him to buzz it again. I'd like to hear the injectors myself. I let him change the last injector because I wasn't sure what the problem is. Now that I'm feeling confident that's the problem I'll probably tackle them myself.


Off topic a little... What's a good brand for injectors? All I've heard of for stock replacements is Alliant. The new one in my truck right now came from a local diesel injector shop. I'm planning on calling him and seeing what he buys, or rebuilds them with.

 

Hey guys i also have the morning cold start. It wont start at all today. How do you perform the buzz test on the injectors? Thanks

 

My 1999 F 250 7.3 manual tranny won't start it was working fine two days ago. This morning I put in the key and the glow plug light went off and it cranked but wouldn't fire. The glow plug light came back on when I cranked it like it wasn't getting any juice.

 

Sorry about getting back so late. I've been busy! Which is good.

Anyhow, welcome to FTE!

As for the glow plugs, how long does the WTS light stay on when you turn the key? It should stay on about 30 seconds when it's cold out. Depending on how cold it is, you can wait up to an extra minute after the light goes out for the glow plugs to burn longer. They actually burn for about 2 minutes when it's cold.

If the WTS light goes out real quick, you have a problem with either the relay or the selenoid. If the light goes out real quick, you can jump the posts on the selenoid with a screwdriver, and hold it for about a minute then try to start it. If you need to replace the selenoid, tell the parts guy it's the glow plug selenoid. I have heard that there is a difference between the GP selenoid and the starter selenoid.

 

I had it into the dealer for the same problems you are talking about and they swear up and down that I needed this Part # F6TZ- 9F838-A not sure what they called it but they said that is all that was needed.

I'll let you know if I get the same problems next cold morning.

 

Nope didn't do a darn thing, same problem if it is not pluged in overnight it smokes like a bugger after cycling the WTS light 3-4 times.

It was in for the recall and they replaced that part for the reported problem.