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76S&S
11-19-2012, 06:53 PM
I went to crank my F350 7.3 dually this evening and it will barely run. Can anyone tell me how to check the injectors to see if I have a bad one or do I have to put it on a computer?

Woe is me....:(

dog paw
11-19-2012, 07:51 PM
Definently get it hooked up to some diagnostic equipment. Way too many possibilities to take pot shots at. Hopefully its something cheap and simple like a cam sensor...They were a weak spot on 7.3's

Cloaked
11-19-2012, 09:00 PM
That 7.3 should not have injector problems, generally speaking. Look to a dirty fuel filter first. However diagnostics tool is your best guess after a filter change.

TayMC197
11-19-2012, 09:45 PM
Glow plugs! That 7.3 is old, it's cold. Glow plugs fail and creates that symptom. Let me know more about exactly it's doing.. Might be able to help you better.

Ben
11-19-2012, 09:55 PM
Definently get it hooked up to some diagnostic equipment. Way too many possibilities to take pot shots at. Hopefully its something cheap and simple like a cam sensor...They were a weak spot on 7.3's

This went out on mine at about 160k. This was a while ago. It was covered under a recall if I remember right. I also put in a new glow plug relay. Got it at international dealer, much cheaper.

Good luck.

jschildm
11-19-2012, 10:14 PM
If its glow plugs it will start hard, but once it is started, run just fine. If it starts and still runs like chit for an extended period of time, then there is something else wrong. Cam Position Sensor is a weak spot on them. If you have someone with a scan gauge or auto enginuity, then you could do a buzz test and contribution test on the injectors to see if they could be the issue. Some more info on exactly what it is (or isnt) doing would help.

If it idles OK, but absolutely won't get out of its own way, then you might check that the EBPV didnt get stuck closed.

76S&S
11-20-2012, 08:12 AM
The CPS has already been replaced, it absolutely died when it went bad.

It cranks (starts) but has a horrible miss. I had an injector go bad about three years ago and the symptoms were similar. Missing is worse this time though.

jschildm
11-20-2012, 01:35 PM
No CEL, I assume?

76S&S
11-20-2012, 03:46 PM
Correct, no CEL.

TayMC197
11-20-2012, 04:04 PM
If its glow plugs it will start hard, but once it is started, run just fine. If it starts and still runs like chit for an extended period of time, then there is something else wrong. Cam Position Sensor is a weak spot on them. If you have someone with a scan gauge or auto enginuity, then you could do a buzz test and contribution test on the injectors to see if they could be the issue. Some more info on exactly what it is (or isnt) doing would help.

If it idles OK, but absolutely won't get out of its own way, then you might check that the EBPV didnt get stuck closed.

Yes a cold glow plug will do that, then the cylinder is flooded and takes it a little bit to start firing properly. A failed glow plug won't ever ignite, which cuases the same symptom to be perminate.

Yes, run a tech 2 or similar device on it if you have it or know someone with it. If not time to visit a service shop. They can check your balance rates on your injectors and make sure they are all firing properly. Normally if an injector fails you'll have more symptoms than just missing. It will white smoke (even at idle), have fuel in your oil, knock like crazy... Might not be all of these but at least 1. Normally injector issues, it will still run and move around okay, just smoke and knock like crazy.

Those 2 things are going to be your most likely cuases... beyond that you are looking at possible turbo issues (i believe the 7.3 is a wastegate setup), valve issues (such as breather valves, bypass valves), Position sensors like jschilm said, ecm/wiring issues.

Sadly I blew my turbo on my 08 LMM Duramax yesterday... I'll spend the weekend rebuilding it... ohh fun Thanksgiving for me. lol

jschildm
11-20-2012, 04:14 PM
As long as the glow plug is still threaded in, I don't see how it would run rough permanently. The relay only stays on 2 min, and then none of them do anything. It doesn't sound to me like that is the Ops issue.

One other quick thing that you can do without any fancy tools is unplug the ICP sensor on the driver's side High Pressure Oil rail. It will then go to a default value, and if it runs OK unplugged, then the sensor is the issue.

mdo817
11-20-2012, 06:29 PM
First thing I would check would be your engine oil. Stupid as it sounds if it is low it will do exactly what you are saying run but run rough with little power.

Sent from my DROIDX using Tapatalk 2

mtajpa
11-20-2012, 10:14 PM
+1 on the OIL and Fuel Filter. These are the first thing to check. If you have been doing general maint. then you may rule this out.

However one thing to look at maybe your valve cover gaskets.:confused: These gasket actually have the injector connetors and the glow plug connections in them. The connections are known to burn up especially if your have been cycling the key to increase the glow plug duration.

Check this out and you will see what I am talking about.
http://www.youtube.com/watch?v=pJ1wyMBvLLc

jschildm
11-21-2012, 08:16 AM
Both of the above mentioned are great places to start. I was just thinking last night that you might check the oil level in HPOP reservoir prior to starting as well. It could be leaking down.

76S&S
11-21-2012, 08:28 AM
Oil level is good and recently changed. I don't think it is the injector connector as when they work loose you usually loose that entire bank (side) of the engine.

It was dark when I last started it and I did notice smoke but couldn't see the color.

I think I'm going to pick up an infrared thermometer from HF, start the motor and check the temps on each cylinder. This should narrow it down. Assuming I can narrow it down to one cylinder, then I will pull the valve cover, start the motor and unplug the injector to see if it stumbles or if there isn't a change. If no change, I'll look at replacing the injector.

Thoughts?

TayMC197
11-21-2012, 11:41 AM
I think its a good start.. It really doesn't cost too much to have the injectors checked. Normally about 100 bucks to have someone run a diagnostics. Saves a lot of guess work.

76S&S
11-21-2012, 02:42 PM
Tay, I just saw where you blew your turbo, sorry to hear that.

I have a turbo on a "cough, cough" pwc that needs rebuilt. Where would you put the job on the difficulty scale?

mtajpa
11-21-2012, 06:52 PM
Oil level is good and recently changed. I don't think it is the injector connector as when they work loose you usually loose that entire bank (side) of the engine.

It was dark when I last started it and I did notice smoke but couldn't see the color.

I think I'm going to pick up an infrared thermometer from HF, start the motor and check the temps on each cylinder. This should narrow it down. Assuming I can narrow it down to one cylinder, then I will pull the valve cover, start the motor and unplug the injector to see if it stumbles or if there isn't a change. If no change, I'll look at replacing the injector.

Thoughts?

The valve covers have 2 connectors on each cover. There are 2 glow plugs, and 2 injector connectors in each connector. You can have a single injector connection fail inside the valve cover. You maybe able to use an OHM meter and read the resistance from the injectors to ground.

TayMC197
11-22-2012, 12:14 PM
Tay, I just saw where you blew your turbo, sorry to hear that.

I have a turbo on a "cough, cough" pwc that needs rebuilt. Where would you put the job on the difficulty scale?

Getting it out and back in is the hard part. Rebuilding it on a level of 1-10 would be about a 3. It's not too difficult. I believe you have the waste gate on your turbo so that will make it easier. Don't let it intimidate you, it's not complicated, just tedious at some points.

Got mine out and found that my variable vanes are shot. So I'll actually need an entire new turbo. Got it on order, should have it back in next weekend.

76S&S
11-26-2012, 10:25 AM
Got mine out and found that my variable vanes are shot. So I'll actually need an entire new turbo. Got it on order, should have it back in next weekend.

That ***....

76S&S
11-26-2012, 10:30 AM
Update:

Started it up over the weekend, (very hard to start!!!) and by the time I got around the engine and checked the temps on each cylinder it was running smoothly.

Since it was so hart to start, I checked the glow plug relay and it had a severe voltage drop. Replaced it and it started right up several times.

The last time I started it last night, it missed (as if one cylinder was missing) and smoked, but eventually cleared up. This leads me to believe that I also have a glow plug gone bad.

TayMC197
11-26-2012, 05:56 PM
Well that's good news! Glad to see you made headway. I had a feeling it was a glow plug issue.

I lucked out and found a turbo with the parts I needed. Dealer let me rob them off of it free of charge since it was trash. I'm up and running.. Runs great..

76S&S
11-27-2012, 11:05 AM
Well that's good news! Glad to see you made headway. I had a feeling it was a glow plug issue.

I lucked out and found a turbo with the parts I needed. Dealer let me rob them off of it free of charge since it was trash. I'm up and running.. Runs great..

Awesome, got a nice dealer there!:D