'05 F-250 Difficult To Diagnose No-Start

Jeff Adema · May 27, 2009

That is how we would identify faulty DDEC V injectors, too. Pull a vacuum on the tip with your handy tester. Aerated and/or contaminated fuel would be my first examination. And as Bruce says, if the springs are broken it will cause overfueling....didn't this thing chug and smoke and such...?

mchan68 · May 28, 2009

....didn't this thing chug and smoke and such...?

YES. Interesting that you should ask. What is more interesting is that after the repair, the vehicle now starts and runs fine, but blowing PLUMES of white everywhere. While monitoring PIDs I noticed EOT pegged at 230, while ECT only got as high as 205 to 210. Soooooooooooooooooooooo, I guess I'll be throwing in both coolers in it too now (despite already having an EGR cooler replaced as one of the many parts from a previous no-start repair by another tech and our shop foreskin while I was in school. See previous post re:parts cannon). Posted Image

This is beginning to become one of "those" vehicles that just won't go away.

Mekanik · May 28, 2009

Originally Posted By: mchan68

Thanks for the suggestions so far guys. I guess my main question is, IS THERE ANY POSSIBILITY OF HAVING BAD INJECTOR(S) THAT PASS THE INJECTOR BUZZ TEST?

And if so, is there any way of determining this, without having to pull all eight to look for any physical damage, or anything obvious?

Absolutely! If the barrel and plunger are damaged from fuel contamination, the "click" test will pass with flying colors but the lower end of the injector (barrel and plunger/nozzle) will fail to deliver fuel properly. In addition to this, the nozzle can be worn where the correct amount of fuel is delivered, but not atomized properly due to deterioration in the nozzle itself. Another lower end failure is from the nozzle spring breaking, in which it will commonly overfuel. How do you diagnose these in the truck? Use Stanadyne (or PM-17a/equivalent lubricity enhancer) Performance Formula in a dramatically heavy percentage. I usually fill the secondary FF with it and see how the truck runs. If it is better, the problem is generally bad injectors or bad fuel. Once the injectors are out, you can also apply shop air or vacuum to the tips and make sure they hold pressure/vacuum. It sounds silly, but it works to identify a leaking nozzle.

Good Luck!

Bruce,

What about opening the relief valve on the fuel system tester to see if the engine starts or runs better as a test?

I had a 7.3l a long time ago that would barely run because the injectors were all damaged by contaminated fuel. If I opened the fuel drain, the engine would smooth out and actually run pretty decent. The way it was explained to me was that the barrel and plungers did not want to move up and down and they got fuel from the side of the injector. So if the fuel pressure drops it will be easier for the barrel and plungers to move up and down.

Bruce Amacker · May 28, 2009

What is more interesting is that after the repair' date=' the vehicle now starts and runs fine, but blowing PLUMES of white everywhere. [/quote']

Did you run it long enough to burn any fuel present in the exhaust system? They'll smoke a while from that.....

Bruce Amacker · May 28, 2009

What about opening the relief valve on the fuel system tester to see if the engine starts or runs better as a test?

I had a 7.3l a long time ago that would barely run because the injectors were all damaged by contaminated fuel. If I opened the fuel drain, the engine would smooth out and actually run pretty decent. The way it was explained to me was that the barrel and plungers did not want to move up and down and they got fuel from the side of the injector. So if the fuel pressure drops it will be easier for the barrel and plungers to move up and down.

I haven't experienced this one, and it doesn't seem to make sense to me. If the plunger were indeed sticking (or if the spring under the intensifier piston were broken), higher FP would make it return easier and function better. (In reality, I think 55PSI wouldn't make much of a difference given the small diameter of the plunger tip. The plunger is about 5/16" in diameter. It's late and my math is weak, but this can't account for more than a few pounds of upward pressure on the plunger) In the cases with low/no FP I've seen, 7.3's sometimes run rough at idle or have low power. I've never seen a case where lowering the FP made the engine run better, usually it's just the opposite. My guess is there was a problem with the inlet check ball next to the plunger. I've certainly not seen everything, though. I've got a cool animation of a 7.3 injector, I'll try to post it.

Posted Image

mchan68 · May 28, 2009

Originally Posted By: mchan68

What is more interesting is that after the repair, the vehicle now starts and runs fine, but blowing PLUMES of white everywhere.

Did you run it long enough to burn any fuel present in the exhaust system? They'll smoke a while from that.....

Yes, I ran it up to operating temperature, at least hot enough to get EOT to peg to 230. Due to the thickness of the smoke, I didn't want to run it any longer. My question is, and still is, how in the hell do SIX injectors fail mechanically all at once? I feel like I've fixed the symptom but not the cause. Here's another good question. Would a restricted oil cooler cause these injectors to fail in this manner?

Bruce Amacker · May 28, 2009

Yes, I ran it up to operating temperature,

I assume this was a road test and not in the bay, right? Running it up to operating temp in the bay won't clear the exhaust system if it's loaded with fuel from an overfueling injector, it could take a hard road test for 20+ minutes to heat the exhaust enough to clear it out.

at least hot enough to get EOT to peg to 230.

What was the ECT at this point?

Due to the thickness of the smoke, I didn't want to run it any longer. My question is, and still is, how in the hell do SIX injectors fail mechanically all at once?

Bad fuel! I've seen it more times than I can count. Quiz the owner in detail, sometimes they'll admit they got a bad load somewhere.

I feel like I've fixed the symptom but not the cause.

Is the truck still around? You stated in your original post "fuel quality has been verified", can you elaborate on this? Have you taken a fuel sample into a glass jar? I'd suggest sending it out for analysis, but realize many SMs/owners won't want to do this. Take a sample from the separator and judge it for clarity, particulates, let it sit a while and see if it separates. Let a secretary or someone in the front office smell it to see if it smells like gas. Try to light it with a match. Pour some into a styrofoam cup and see if it melts the cup. Put it in the shop freezer for a few hours and see if it clouds or gels. Many bad fuel samples will pass these low level tests, but you gotta start somewhere. We used a diesel hydrometer to test fuel, too, but I was never convinced enough to bet money on the results.

Here's another good question. Would a restricted oil cooler cause these injectors to fail in this manner?

I've heard this hypothesis kicked around, but feel there would be overheating problems associated with this, also, or at least DTC's.

Good Luck!

Posted Image

mchan68 · May 29, 2009

Well, injectors, coolers and a fuel pump it is (I was able to actually road test under load after the coolers when it wasn't smoking), for the win!!!

HOWEVER, ECT/EOT spread is a little more than I'd like it to be. On good road test, I got ECT ranging between 158 to 163, while EOT remained steady during the whole drive at 167. It sure is a long way off from 195 to 210 for ECT while EOT was pegged up there at 230, prior to replacing the coolers. Anyone else done the new cooler "rebuild" finding similar ECT/EOT reading spreads like that? I prefer them to be almost dead on equal.

Brad Clayton · May 29, 2009

The few I've done were close enough for goverment work, afterwards.

Bruce Amacker · May 29, 2009

Well, injectors, coolers and a fuel pump it is (I was able to actually road test under load after the coolers when it wasn't smoking), for the win!!!

What made the smoke go away?

HOWEVER, ECT/EOT spread is a little more than I'd like it to be. On good road test, I got ECT ranging between 158 to 163,

Huh? Fahrenheit, right? Your 'stat's junk.

while EOT remained steady during the whole drive at 167.

Both temps are too cool.

It sure is a long way off from 195 to 210 for ECT while EOT was pegged up there at 230, prior to replacing the coolers. Anyone else done the new cooler "rebuild" finding similar ECT/EOT reading spreads like that? I prefer them to be almost dead on equal.

We just did both coolers and a bunch of misc on an '04 F550 wrecker. 15 mile RT unloaded on the highway, 60F ambient, showed ECT in the high 190's when done with EOT 205-212F, with a max spread of 12F. Ford revised the maximum spread to 15F but I still use 25F for diag. 15F is too close to normal for me.

Good Luck!

Posted Image

mchan68 · May 29, 2009

Originally Posted By: mchan68

Well, injectors, coolers and a fuel pump it is (I was able to actually road test under load after the coolers when it wasn't smoking), for the win!!!

What made the smoke go away?

I suspect the coolers obviously.

HOWEVER, ECT/EOT spread is a little more than I'd like it to be. On good road test, I got ECT ranging between 158 to 163,

Huh? Fahrenheit, right? Your 'stat's junk.

That's what my shop foreskin and I were thinking.

while EOT remained steady during the whole drive at 167.

Both temps are too cool.

I agree.

It sure is a long way off from 195 to 210 for ECT while EOT was pegged up there at 230, prior to replacing the coolers. Anyone else done the new cooler "rebuild" finding similar ECT/EOT reading spreads like that? I prefer them to be almost dead on equal.

We just did both coolers and a bunch of misc on an '04 F550 wrecker. 15 mile RT unloaded on the highway, 60F ambient, showed ECT in the high 190's when done with EOT 205-212F, with a max spread of 12F. Ford revised the maximum spread to 15F but I still use 25F for diag. 15F is too close to normal for me.

Good Luck!

Really? Why is that? I've been used to seeing ECT/EOT almost at identical temps after oil cooler replacement, up until my first oil cooler "rebuild" on this truck.

Bruce Amacker · May 30, 2009

What made the smoke go away?

I suspect the coolers obviously.

I thought you RT'd it after the coolers were installed and it still smoked, like the exhaust was fuel-loaded. No?

Ford revised the maximum spread to 15F but I still use 25F for diag. 15F is too close to normal for me.

Good Luck!

Really? Why is that? I've been used to seeing ECT/EOT almost at identical temps after oil cooler replacement, up until my first oil cooler "rebuild" on this truck.

I don't ever recall seeing them nearly identical on a RT. EOT has always been 10+ degrees higher than ECT on a RT. Shop temps don't count, as EOT doesn't come up to "true" temp without a load.

Why would I use 25F instead of 15F? The truck we just did (both coolers replaced, not just the heat exchanger, clean the turbo, harness, EGR valve, IAT2, oil leaks, and a bunch of other piddly stuff) ran 12ish degrees apart, like I said. If it hit three more measly degrees we would condemn a brand new $600 cooler as bad? You're not leaving much room for error. To me, if an oil cooler is restricted, you're going to see a hell of a lot wider gap than 15F. I've seen several with 50+F difference.

Anyone else care to comment, especially on EOT RT temps? I wish I took more recordings....

Posted Image

GregKneupper · May 30, 2009

I also see temps over 10 degrees after cooler replacement. When you road test are you driving it in third gear wot? That is how I test the oil coolers. I have never seen one where ect and eot mirror each other. I drive them about 8 miles like that and it gives me a good idea how the oil cooler is operating. If it is plugged it will usually go above 15 degrees in the first few miles.

Brad Clayton · May 30, 2009

I imagine they would run a little hotter for a little longer down there in your neck of the woods. What's your temp right now? 100 degrees 102 in the shade?

Yesterday it was in the 40's here and we had the doors in the shop shut all day. I wore a jacket to and from work. Hard to believe it's gonna be June tomorrow.

Tony302600 · May 30, 2009

Originally Posted By: mchan68

Well, injectors, coolers and a fuel pump it is (I was able to actually road test under load after the coolers when it wasn't smoking), for the win!!!

What made the smoke go away?

HOWEVER, ECT/EOT spread is a little more than I'd like it to be. On good road test, I got ECT ranging between 158 to 163,

Huh? Fahrenheit, right? Your 'stat's junk.

while EOT remained steady during the whole drive at 167.

Both temps are too cool.

It sure is a long way off from 195 to 210 for ECT while EOT was pegged up there at 230, prior to replacing the coolers. Anyone else done the new cooler "rebuild" finding similar ECT/EOT reading spreads like that? I prefer them to be almost dead on equal.

We just did both coolers and a bunch of misc on an '04 F550 wrecker. 15 mile RT unloaded on the highway, 60F ambient, showed ECT in the high 190's when done with EOT 205-212F, with a max spread of 12F. Ford revised the maximum spread to 15F but I still use 25F for diag. 15F is too close to normal for me.

Good Luck!

The engineers i talk to say that 10degrees is the maximum. When i would do int. drivebility problems on 6.0's i would always put up eot and ect just to see what newer trucks would show and would never have over 3-5degree difference on a cruise after reaching operating temp. I would always stick with 10degrees as a sign of a problem starting to get worse, IMHO. Usually the bad coolers I had were 30-100 off from each other but that would show up real quick.

Keith Browning · May 30, 2009

My Posted Image if I may - I don't nit-pick. What I have observed over time is that on a good specimen the temperatures will typically fluctuate within 10-12 degrees(f) of each other and I use 190-200 degrees(f) as a medial baseline. Since I see a wide range of truck sizes and weights some get hotter than others.