Your buddy with a 2004 was likely a 6.0 liter diesel, correct?

And are you sure it was the PCM that was replaced and not the FICM?

To answer your question on the PCM, it is pretty rare.

 

i have the exact same truck with 278,000 km and the same problems. i am pretty sure my glow plug relay is only working when i am trying to test it. i try to listen for the click but it's hard to tell if it clicks because of ambient noise around me.

i am going to wire in the indicator light for the relay tomorrow to see what it's actually doing.

FYI, starting fluid is supposed to be one of the worst things you can do to these engines according to the experts. the explosions it causes in cylinders can blow out piston rings which is really, really bad.

 

Did someone pull and flow test the injectors OR are you throwing injectors at it because some mechanic told you the injectors might be worn? The reason I ask is that there are numerous 7.3's with well over 200K miles on them with them with the original injectors. I thoroughly doubt there is any problem with the PCM and skeptical of the injectors being bad. The other thing you need to do is ohm out the harness for the injectors and glow plugs. Search for UVCH and you will see how to check the wiring harness for the injectors & glowplugs.

 

Lots of great info guy !! Thanks

 

First thing I am going to do is the GPR. Second will be GP. Lastly will be the injectors. But I bought it from a guy who works for ford. He had it all tested by ford. They found that #8 was really badly worn. They replaced it and recommended , because of the wearing to replace all.

 

Well, without bench flow testing, I don't know how you could determine injector "wear" with injectors in truck and I wouldn't replace injectors without my knowing the injector(s) had a problem. I know I wouldn't rely on a test performed by any dealership...they throw parts at these trucks because they don't/won't/can't perform real repair diagnosis and they make money on parts. You don't know how many times over the years we have seen expensive parts stuck in by Ford dealerships and billed to the owner, which did NOT fix the problem.

Be sure to ohm out the harness going to the injectors and glow plugs! Do you know the GPR is faulty or that the GP's are faulty? Have you tested the GPR, GP's, and harness??

 

Sounds like you're on the right track, fix it the right way - never fall into the ether trap on these trucks! I've seen 1st hand (friends truck) what happens when ether gets used to try to start them and I have the pieces of the air box sitting in the garage as proof. I tried to tell them it was a bad idea but they wouldn't believe me until the pieces were flying past their head. I did convince them to do the 6637 mod because the air box was gone, and pretty sure they won't ever try ether again. Luckily they did not hurt any internal parts or kill themselves.

 

Unless your truck runs like grap, I would guess your injectors are alright also. Now if these were IDI motors, prepowerstroke, then sometimes thats exactly whats wrong. Different type of injection set up. I have a bad fuel knock that just started again. I put Clays Frx on, and it all but went away. Its back. I know its number eight so I am going to replace that injector. I tested it once where you turn off one injector at a time, and when that injector was shut off, the knock stopped.

Chet

 

Only runs rough till it is warmed up. Then runs pretty good. I after reading everything I am going to do the relay, install the LED and then see if that fixes the issue. With warmer weather here it will be a while before a true test. I have not tested the relay or the glow plugs. But it will not start I mean will not start without plugging it in. So if relay and gps were good then then not getting power.... For $40 I will buy a relay...

 

For sure on the relay. Heck, if glow plugs have never been changed, them to.

Chet

 

I added a GPR indicator light in the dash a few years ago (not the one in the dash). It just lights up when the GPR relay is energized and goes off when it's done. the this past fall the light started acting up (not lighting up, going off too soon, etc) and that gave me the warning the GPR was going. Ordered a replacement from Moser and everything is squared away again. No problems here starting down into the teens (as long as I hook up the block heater when it's that cold) and even in the 20's w/o the heater as long as the glow plugs are allowed to cycle and get nice and warm.

JP

 

Ok it is update time for my truck! I have switched to synthetic motor oil. I have tested and retested the GPR... All good. I just replaced all 8 GP as there were a few burnt out. Now when I try to start the truck it pushes white smoke. It still will NOT start without block heater. I am now looking into the fuel heater orings. Since when my truck runs A1 once it is started and I begin having starting issues after it sits more than 8-10 hours. My next guess is that it is fuel delivery...... Reminds me of the old snowmobiles when fuel gravity drain all the way back to the tank!

 

Welcome back! What weight synthetic are you running and what temperatures are we talking about here? You say the relay is good, so you've confirmed that juice is flowing out to the plugs, about 1 or 2 minutes post start-up? You should be able to read a marked change in voltage from initial KOEO to the same reading about 2 minutes later. Easy check.

The fuel bowl heater isn't a fan favorite. A lot of guys keep it unplugged. I'm not sure of it's usefulness, but someone will probably chime in about that.

If you think you're losing a prime, try cycling the key 2-3 times before trying to start. This will make the fuel pump run, filling the fuel bowl to the brim. See if you have any performance change. What can muddy the waters is that you're now cycling the GP's multiple times. Either way, should be an easier start. Give it a shot.

 

Have you checked the level in your HP oil res? Should be within about 1/2" from the top. If not you have oil leaking back down into the sump and the excessive cranking is filling the HP oil. Just a thought

 

You can leave the fuel bowl heater as suggested but you wont have the "water in fuel" function if you ever get water in your fuel.