I need help to determine if i got bad injectors. I got a 2002 F350 with 110,000 miles and i just put new valve cover gaskets and wiring harness. I get white smoke continually after startup and bad vibrating. I did all the 9 pin and other tests with the IDM and stuff. I now get a p0269,275 and 278 codes on my new AE scanner, after running a cct i got a cylinder injector circuit contribution / balance fault on cyl 3,5 ,6.

 

did you check the connection at the uvch? did you do the 50 cent mod to hold the clips together...sound like one of the harnesses are loose or not plugged back in.

 

yes i just went back in and made sure everything was tight and all is good with uvch, even went ahead and put in a couple of gp,s while i was there.

 

make sure the connection is tight on the inside and the outside of the valve cover. i knocked one of mine loose and had the exact same symptoms...did you do the 50 cent mod while in there? im sure others will be along to help more...but that is all i can think it would be

 

yes and everything is tight and it all ohms out

 

im sure some other more knowledgeable guys will be around soon to help....stand by

 

i hope so i have been going through this thing for a week

 

Ok...here's the deal.

If you're getting white smoke, you're getting fuel (or coolant depending on the smell). We'll assume it's fuel. An open circuit in the injector wiring WILL NOT cause an injector to dump fuel into the cylinder....in fact, that injector will not do anything, so therefore you will get a miss and nothing else. If you have a short in the injector wiring, you will get one shot and then burn up the coil in the solenoid so no more fuel due to an open circuit.

You're getting fuel, we've established that. Now it's time to determine whether you have too much fuel, too little fuel, or no compression in one or more cylinders.

 

see...i told you someone way more knowledgeable than me would be along...thanks cody

 

yes smell of fuel, so your thinking is that it's not an injector but possibly cylinder related? if so compression test in the a.m.

 

These are the steps I'd take:

With engine running (badly as you say), remove the oil fill cap. How do the crankcase vapors come out of the tube? Smooth flow of vapors (yes, there will be some and that's normal) or "puffs" of vapors that coincide with the miss?

If we have a normal situation there, the next step is to check fuel pressure. Low pressure usually won't cause rough running, but it can cause white smoke due to insufficient fuel for combustion. There's nothing on a scanner that will tell you what fuel pressure is, so it will take a gauge and a little time if you don't have one.

Using a scan tool, the injection pressure would be my next check. A lack of pressure there can definitely cause both a rough idle and white smoke. It should be around 480-580 PSI at idle and the IPR duty cycle should be in the 9-13% range. The more load, the higher the pressure should be. The IPR duty cycle should climb with load/pressure as well (since it controls the pressure).

If there is no fault found there, the next test can be done by removing the glow plugs (since you'll be there for a compression test anyway). Remove all 8 glow plugs and disable the injection system. This can be done by pulling the PCM relay diode, cam sensor plug, PCM connector, etc. Pick your poison. Crank the engine and watch for fuel vapor. There will be some oil since you'll lose about a teaspoon in each cylinder when you remove the glowplugs. You'll see fuel vapor and smell it if there's a problem.....if you see fuel vapor from ANY cylinder while cranking with a disabled fuel system, you either have an unseated injector and fuel leaking directly into the cylinder or you have a stuck-open injector. Typically it takes a REALLY big leak to completely disable a cylinder (and will often kill the rest of the cylinders in that head). A smaller leak will result in a knock and puffs of black smoke out of the exhaust.

Before I get too much farther ahead, let's see what you come up with initially.

 

the ipr is about 480 at idle, IPR duty cycle is 14.84% so is seems ok and compression test will take a few days to get stuff together for it and get done.

 

Nice info! Reps sent.
Will pulling the PCM relay diode also disable the fuel pump? For this test do we want the fuel pump on or off?

 

Good call, Greg. Yes, it will disable the fuel pump as well.


However, there is enough fuel in the fuel rails to fill the injectors for quite a few injection cycles. Best bet is to just pull the camshaft position sensor connector in this case.

This diagnosis comes from my many years of Duramax repair.

 

sorry wrong link