The dealer is trying to decide if my problem is the preasure controll valve that is part of or attached to the CP3 of if the problem is the p. relief valve connecvted to the rail. I assume he has determined the rail is loosing preasure. He can't decide which valve is causing the problem

 

Sorry ment to spell "where to mount the pump" . Please forward all of my spelling, puctuation and gramatical errors to my college english 101 instructor. This will further her dissapointment in allowing me to graduate.

 

He should just cap the relief valve on the rail so he can narrow down which one it is.

 

Thanks I will forward your sugestion. Are some of you caping your rail p. returns permanently?

Thanks

 

computer wants 54-5500 psi - when it dies shows 2400lbs. When the mechnic starts the engine, his computer diagnostics show the FCM is asking for 5400lbs and the rail (still taking reading from his software) is providing 5400lbs - When it stalls, or just before, the rail p. reading (software) drops to 2400. So rail preasure is either droping or is precived to be droping. I have asked him to plug relief valve. He siad he belives he may have fitting to do so. I asked him if he has a physical rail preasure guage. He said no. I said I would call City diesel of decatur to see if they have one.

I am at least happy that this dealer mechanic is talking with me. He is not arrogant and admits he dosen't know everything.

 

Di Pricol has a rail pressure gauge that goes right to the rail pressure sensor. I have one in my truck and it is great for tuning as well as diagnosing things like this. Capping the rail is easy to do. That will help narrow down whether it's that or the FCA. Might be getting somewhere at least.

 

I hate to butt in, but since we are all sharing moments, I have a new developement. For some strange reason, I decided to take off early, swing by the Dodge dealer and pick up a new Fuel Control Actuator (FCA). About 2 months ago, I had overhauled the original one and wasn't 100% happy about it (the little piston in it just didn't seem to be slippery enough). Anyway, I put it on. My truck still takes about 3 seconds to fire up, but it will do it hot or cold. It was getting to a point to where It sometimes wouldn't start after 3 or 4 rounds of 30-second cranks (would have to use ether). So it's a LOT better it seems, but not 100%. I still want to do a injector return flow test but I still have to get the fitting. I'm calling Dodge to see if they can get me one (Service Tool #9011 & 9012...SPX/Miller/OTC). If the FCA was sticking either open or closed, I suppose it could cause some hard starts. I'm a little suspect of the Cascade Overflow Valve on the CP3 now. Maybe I'll pull it out and see if I can disassemble and clean. Man, what road we've all been down!!!! Keep talking guys......- Curtis

 

Hmmm The one thing about my 04 - alwasys started - when it started - 2-3 secounds. What is an injector return test? Can you check rail preasure. How can I get a guage. Is their a part # for an adaptor to check rail preasure. Is their a hand sacanner for this truck $$$$?

The mechanic that is working on my truck doesn't believe it is going to be the preasure relief valve (rail) . He belives that when the P. relief goes it goes hard and would not be as intermittant as my problem. does seem that p. relief would be worse the more preasure is put on it. So if your truck runs good after starting it would lead me away from the relief valve. Has some logic. Boy I would wan to know that rail preasure and the ECM request preasure when it is hard to start. With the older disels you would certainly think supply leak down - but with your fire hose attached not the case. I guess I would be curious about the compression with 100k . Rail p # would help

Good luck

 

Ok Di Pricol - thanks I'm looking that guage up

 

This is probably stupid and pointless to even mention at this point but since I now have a raging headache from reading this mess I will say it anyhow. I asked this on the first page of the thread and haven't read an answer anywhere but I could have easily missed it. Probably the most obvious thing so I assume it has been eliminated as a possibility but....

HAS THE FUEL FILTER BEEN REPLACED SINCE THE PROBLEMS BEGAN?!?!?!?!?!

And I don't want to hear its been looked at and looks clean. Put in a new one ! At this point it will be the cheapest thing you can possibly do. Of all the problems I've ever seen with a Cummins (not that its alot) I would bet over half were related to a dirty filter. Changed regularly or not, you can't see the condition of the fuel you pump in your tank so who knows if its crap or not. Just trying to rule out the obvious here.

 

Yea, I have gone as far as replacing fuel filters every other day for several days.

Quadzilla now makes a Rail Fuel Pressure Monitor. It's a small digital readout that velcros to your steering column. It reads the Common Rail Fuel Pressure (HP). An add-on sending unit is available that mounts at the CP3 inlet banjo bolt so that it will read LP pressure as well. You can watch the HP or LP fuel pressure while cranking or running. The whole thing is about $200, but worth every cent.

Daimler-Chrysler specifies an injector return flow test to check for excessive return flow from the fuel injector return flow header. The CTD cylinder head has a common passageway in it that returns fuel that is normally used for injector lubrication back to the rear banjo bolt fitting on the fuel filter canister and then back to the fuel tank. The total return flow from the injectors should not exceed 180 mL/minute (6 oz./min.). The way to test that is to remove that rear banjo bolt and install fuel test fitting #9012. It's a fitting that has a hose barb on it and takes the returning fuel and directs it through that hose barb, which you connect to a piece of hose so you can collect the returning fuel into a container. You start the engine, and collect the returning fuel for 1 minute. If you collect more than 180 mL, your injector(s) are returning too much fuel. There are ways to isolate injectors one at a time to aid in detecting how many are bad. I'm still trying to get that test fitting. Dealer was no help. However, after replacing my Fuel Control Actuator yesterday, my truck is running almost perfect, hot start or cold start. Praise the Lord.........- Curtis

 

FCA - sounds like a gang in LA. I like the injector return test. Would that pick up an injector that is stuck open? Are you saying you can get a fitting to isolate injectors. The only method I know of now is to use the dealers computer test sytem that electrnically through the computer turns off individual injectors.

Before you replaced FCA did you watch low and high FP using the Quadzilla? If so - what did you see?

Thanks Philip

 

No I have not replace the filter since my injector was replaced. But I hve seen nothing to indicate a cloged filter. If it turns out to be a filter I will move to Irag to drive a fuel truck for Haliburton.

 

The only way to isolate an injector other than the dealer's electronic method would be to disconnect the metal fuel feed line to the injector tube and screw a plug in it to cap it off. If you do that and run the flow test, and come up with a reduction in the amount of collected fuel, you know you have at least one of the leakers identified. I wonder what would happen if you fired it up with the valve cover off, and disconnected one or both of the wires that attach to the fuel injector.......??????

 

I am glad the dealer is looking into this problem...there is nothing worse than talking to a wall. I hope they find something soon! Keep us posted.