[TommJr]

Last week I took my 03' Dmax into the dealer for a possible injector/fuel pump hard starting issue. When I picked the truck up at the end of the day, the service tech told me he did every test possible, including tests with the tech ll, and he assured me it wasn't a fuel injector problem.


Yesterday, I had a chat w/ John from Kennedy Diesel, told him all the same info I'm relaying to you, and he said in his professional opinion, that he still thinks that it is an injector problem. He also told me that I should ask my dealer if they performed a fuel system return test. (I'm not a mechanic, so I have no idea on steps to perform such test, and I'm not so sure the tech at the dealer does as well.) So i asked the tech, and he said he did.


I'm taking the truck to the dealer tomorrow for this claimed fuel pump thingy. They told me that there needed to be a certain amount of pressure at this pump, and there's not. So they are going to replace.


I guess I got ahead of myself, Here's the problem. Some days truck starts great(1-3 seconds of crank) sometimes starts hard(15-45 seconds of crank). Have nicktane filter kit, add additive every tank. Also change factory fuel filter every other oil change. When truck finally starts, the truck goes like hell.


Maybe you have some Ideas on this issue. If it is an injector issue, how do you go about telling the dealer that their tech is stupid. And how do I stop them from shotgunning parts every other week and still the problem remains? If everyone that I talk to knows and thinks that it is an injector issue, but the dealer tells me it's not, who do I believe?





Maybe you can give me advice on this subject. And if problem still remains after tomorrow, maybe you can get me some info on how calmly put some well needed pressure on dealer.

 

[dmaxalliTech]

Can they duplicate concern? If so, tell them to fix it, you dont have to tell them that the tech is stupid, just tell them to fix the truck, if they havent duplicated concern, your problems starts there, hard to chase something that isnt there at the time. I agree with JK, sounds like injector issue. Injector return volume test is very involved test that will tell you in the best way we know what the condition of the injectors is

 

[TommJr]

I apologize for the hassle, but Can you tell me what this return system does in layman terms. I have no idea how this faulty system can tell me if I have a bad injector. And if the return system is bad, can't they fix the system.


If they tell me that the high pressure injector pump is bad, will problem persist? Or will the problem remedy for a while until the pump can't keep up anymore then trash out again? If the injectors are bad wouldn't this problem happen everytime I cold start the motor? Wouldn't truck smoke? Wouldn't I notice a difference in performance? The problem occurs on very random times.





Thank you for all the help, and I again apologize for having to deal with a unexperienced diesel owner.

 

[dmaxalliTech]

in simple terms the return volume test will check the injectors ability to pass fuel. each injector should return 3 ml of fuel per 15 seconds of cranking, one returning more might not be putting fuel in the cyl, one returning less is dumping too much fuel. each bank should return 12mls of fuel per 15 seconds of cranking, if both return less, then pump is supect. its kind of confusing, but its the best way we have to test these things at this piont. injector could have intermittant problem that wont show up all the time. seen it, got burned by it. The steps to test are very lenghty and some dont want to do it but for a proper diag........it must be done. I dont like doing it myself.

 

[TommJr]

I got the truck back today at 4:30. Replaced fuel injection pump. Truck runs the same as it always did. I guess the future will tell how accurate the tech was. He sent some paper work with my truck, I have no Idea what kind of print out it was, but it had some sort of read out from the rail pressure sensor and had a bunch of other readouts on it. I'm not a mechanic so I have no idea what they were. But I noticed that there was no such readout on fuel return pressure. ( If that even exists).





Thanks for the info, I'll keep you informed if the problem continues.