Hey guys I haven't been in here for a while now (I'm so broke the only upgrade I can put in my truck is fuel) but I've been having a problem for a couple months now. It started out just being a little slow to crank and running funny for a minute or two but it's gotten worse to the point where if I don't crank it for a whole day the next day I'll have to use Ether to start it. It runs like a gas motor that's missing one cylinder for several minutes after it does crank, the colder the morning is the worse it runs. At first I thought it was a bad injector but it clears up and runs fine (for 332,000 miles) after about 10 minutes but that wouldn't require ether to start after sitting for a day. I read something in the new Diesel Power about the 6.0 having HPOP problems and the symptoms they described are almost exactly what I'm having. Does a leaking HPOP in a 7.3 have the same problems? Hard start, no start, rough idle, no power, bad mileage. Could it be maybe air in the fuel lines that has to work out after a few minutes? I have a cai, 4'' exhaust, Stupidchip, and Wicked Wheel nothing done to the tank, fuel lines, or injectors. It's getting worse but doesn't throw a check engine light and it clears up before I could get it to a mechanic (even if I could afford that). Any help at all is greatly appreciated guys. Thanks

 

Quote:

Originally Posted by Shade

It runs like a gas motor that's missing one cylinder for several minutes after it does crank, the colder the morning is the worse it runs.

I understand broke. I'd really start with confirming the glow plugs are good, and the GP relay is good with a multimeter first. This can be done by reading through the harness on the inboard side of the valve covers. This could also help spot if your having some UVCH connection problems.

Are the batteries and connections in good condition? You can also read voltage when trying to start. Needs to be min 10.5 volts.

But you should stop with the ether, bad mix.

 

It may or may not be your problem. Warn injectors will have similar symptoms you describe. At 300k miles it may be your issue. Google "Swamps injector diagnostics" you will find an informative write up on 7.3 injector diagnostics. You can also try Swamps diesel site. I don't know how to post a link or I would for you. Good luck.

 

Oddly enough, I was just asked the ether question on the phone yesterday.

Ether with gas - OK... spark dictates ignition timing.

Ether with diesel - ver bad... compression dictates ignition timing. You never know when she's gunna pop and it could be at a time that breaks stuff.

That last link in my signature could help you out.

The 50-cent mod costs just that (or less for washers).

A full set of new glow plugs cost less than a full tank of fuel.

 

Here's my 2 cents and I do hope it helps.

Start with the basics and that would be the batteries and starting system. Make sure your batteries are in good condition and fully charged. Make sure there is no corrosion on the battery terminals, posts and especially in the cables themselves. If so, clean the corrosion off and replace the battery cables. You can do a voltage drop test on the batteries and starter. If it's cold where you live plug your truck in. I live in Northern Nevada and in the winter my truck gets plugged in.

Next test out the glow plugs with a meter as stated above and the GPR. IMO if one is bad, change out all of the plugs. I recently installed the GPR mod for about $5.00 and I believe it helps thoroughly warms the plugs before starting. In the past when I would start the truck I would get a SES light after starting. I'd pull the code and it would always be for the glow plugs. After installing new glow plugs I would get the SES light and code again but it would happen occasionally. Then I decided to count to 10 after the wait to start lamp would go out and the SES light only came on during the winter months. This year in Sept I installed the GPR mod and allow the light to go out before starting the truck and since Sept I have not had an SES light or glow plug code.

Since you have over 300,000 on your truck I would next consider the injectors as stated above and start by troubleshooting them. I was talking with the guys at Sierra Diesel and they stated that the 7.3 could go abt 350,000 miles on a set of injectors based upon their experience. That would fall in line with the mileage of your truck and how well the injectors were taken care of...oil changes, fuel additives, air etc. I plan to perform the Hutch mod soon, I have all the parts but am waiting for better weather. I'll also install the FRx fuel rail crossover as well.

I use Diesel Clean at each fuel up. I get better MPG using it. The HPOP oil and oil in the rails is changed out at each oil change abt 8500 miles and a sample sent to Blackstone. This extra effort I hope will make the injectors last as long as possible (265,000) miles on the injectors.

Again start with the basics and work forward. Good luck
Jeff

 

1. Batteries and/or cruddy connectors for the cranking part. Don't forget to clean starter end too.
2. Clean fuel filter? Blow back fuel feed line from pump to tank...just because you can.
3. Pop off IPC connector look for oil in it. Try cold start with it unplugged.
4. If it's been cold mornings there, check the GPR.
5. Reasearch IPR's here, then try the remove and clean the IPR trick (search for procedure here).
6. Being broke like the rest of America and getting worse, AE no doubt is not an affordable option so use/borrow pressure gauges for checking HPOP.
7. Resistance checking the GP/FI's as described above. Search here for procedure.
8.. Going deeper, injector poppets maybe o-rings. There's procedures on here too if it gets to that.

A. You say after 5-10 minutes or so it runs normally?
B. You say it only does this if it sits the whole day? How about after a 15-30 minute stop?
C. If it's been cold, have you tried the jump the GPR for 30 seconds trick just because?
D. Average level of fuel tank during your episodes?

 

My connections are good, the truck turns over fine it just don't want to fire/start like it should. After it has ran long enough to run smooth like it should it's fine the rest of the day even if it sits for several hours, long enough to completely cool down. The fuel level varies from full to 1/4 tank since it does it every day now. Where is the gpr? I assume that's glow plug relay? What's the IPC connector? Sorry, I've been gone for a little while so I'm behind on all the initials again. I'd be glad to plug my truck in but I don't have a plug, also it started doing this (much milder) when it was still hot outside. Yes my fuel filter is good and I always get fuel from busy stations, I run Diesel Clean every two or three tanks and try not to run less than 1/4 tank of fuel

 

Have you tried plugging it in for a couple hours before you need to start it? Worn injectors can sometimes be extended by trying this.

If you wanted to troubleshoot the injectors being worn, you could pull the valve covers and observe the oil discharge during startup. Buzz tests can help point towards issues as well.

As for question on locations, yes the GPR is the glow plug relay(can't remember for sure though the '03's might have GPCM(GP Control Module, but you will know because it won't look like the pic below), the ICP(Injector Control Pressure Sensor) is located on the front of the driver's side head. Here's a pic that will help some.

 

What you described in your original post is a classic problem with UVCH. Where at in SE GA are you? I am in Augusta, GA. Do you have Auto Enginuity or a way to do a buzz test. That could tell you wether all of your injectors are firing electrically or not. Depending on how far South East you are I could drive down this weekend.
The Under Valve Cover Harness(UVCH) 50 cent mod will not cost you anything except two quarters. The Glow Plug Relay(GPR) is the relay in the center of the engine bay that is further back. The one in the front is the Air Intake Heater(AIH) relay.
If you are looking at the relay from the front of the truck.....using a multi meter that has been verified to show voltage on your battery first..... on DC volts place the red lead on the LARGE terminal on the left side and the black lead on the negative battery terminal. You should have 12 volts or what ever battery voltage is on that terminal ALL the time.
Now place the red lead on the LARGE terminal on the right side(Driver's side) and the black lead on the negative terminal of the battery. Now have an assistant turn the key to the ON position and check the voltage. You should get 11-12 volts as soon as the key is turned on.

Now if you want to go a step further and verify that your UVCH is plugged in then you can do the following.....
Unplug the connector that goes into your UVCH on the outside. The pinout is as follows:G-G-I-I-C-I-I-G-G
G=Glow Plug
I= Injector
C= common for injectors
With multimeter set to resistance/ohms Place one lead on the center pin(best to use an alligator clip for this. Now place the other lead on each "I" pin one at a time and leave the other lead on the center pin.
What is the resistance reading for each of the Injectors? I think these are usually 3-6 ohms.
OK, now for testing the Glow Plugs...place one lead on the head directly on the metal and the other lead one at a time on each of the "G" pins. These are usually 0.5-1.5 ohms. The lower the number the better.
Now do this for the other side. Exactly the same procedure. You should report back here at least 16 numbers. 4 glow plug and 4 injectors per side.
What are the 16 readings? Keep the sides seperate and try to give us the numbers from the front of the head to the rear of the head just like this G-G-I-I-C-I-I-G-G. Remember that the C will NOT have any number associated with it as it is only the common for each injector on that side of that valve cover.
I will PM my phone info.

 

I posted in the wrong thread on this message.

 

Are u running any sort of additive in the oil? Its really sounds like its time for injectors. But sometimes, people put stuff like Lucas oil treatment in and it causes issues like u describe.

 

http://www.dieselpro.ca/Poppet%20Valve.pdf

 

It's like a belly button, we all have one. Look behind your bumper on the driver side, or follow the orange cable from your oil filter mount. Plugging it in will warm the oil and help starting. Then I think the problem is (more likely) bad glow plugs or (you pray to the wrong gods) bad injectors.

Keep us posted when you ohm the glow plugs.

 

Like aawl said. It is probably zip tied behind your bumper on the driver's side. Mine has the plug cut off because the Previous Owners were stupid. Oh yeah. Check your PM's

 

I used the Lucas Oil Treatment for a year (3 oil changes) with oil analysis from Blackstone. The results showed little difference so I quit using the Lucas. Now straight 15-40 Delo.