Hi FTEs,

I am in need of some help on testing my injectors and advice about the same.

Vehicle:
2002 F-350, 7.3 liter diesel, 2wd, 6 spd, 163k miles, no mods

Background:
At 156k miles, check engine light came on and mechanic told me #8 and #3 injectors were throwing codes. Mistakenly took advice to replace all 8 injectors (said another way--did not do enough homework on FTE). Anyway, I have taken the long term view on this repair. (it was throwing smoke and could definitely smell the diesel so likely at least #8 was out) Replaced with OEM stock injectors, valve cover gaskets and under valve wiring harness.

Issue:
About 4,500 miles later I started hearing a "thumping" sound through the air box. Fuel mileage dropped about 2 miles per gallon. Definitely strong diesel smell when idling at stop lights, etc. Also felt like I had to down shift earlier and more frequently when pulling a load. Based upon some videos and posts here plus a couple of e-mails with FTE members, I felt like the thumping was related to an injector issue.

What I have done:
I do not have AE so I had the mechanic do a cylinder contribution test which showed #8 and #3 under performing. (Sorry, I do not know how much they were out of spec.) Though the wiring harnesses were new, did the ohm test on the 42 pin connector. I then pulled the VCs to do a visual and check torque.

Results:
A) Pin Test--all were consistent but #3 seemed to be .3 ohms less. When the truck cooled down, retested and all seemed within .1 ohms of each other. (used inexpensive HF which would not zero out so only guessing that they were all near 3 ohms)
B) Torque on the injector retaining bolts--#2 less than 50 in/lbs, #4, #6, #8 somewhere between 70 to 80 in/lbs, #1 (silver hair moment), #3 less than 80 but more than 60, #5 & #7 between 90-100. (truck was still warmish during this)
C) Pushrods appear to be okay. Have not run yet with VCs off.
D) Air box is tight with no visual issues.

So I re=torqued to 120 in/lbs. Still need to warm up and retest the torque. I will get the HF compression tester and do test while VCs are off

Questions:
1) My OEM parts warranty is over in a few days so I was wondering if there is another way to test the injectors with the VCs off?
2) Since the truck was running pretty well but the thumping through the air box, it seems like disconnecting each injector one-by-one would not tell me much.
3) Would the fact that the torque was so far out (especially #2) cause the symptoms like fuel mileage drop and loss in pulling power?
4) Is there something I should look for when I start the truck other than squirting oil?
5) Would it be prudent to pull #2 to make sure nothing happened on the original install to prevent proper torque? (a bit beyond my experience but nothing like the present!)
6) Am I missing something?

Thanks,

Jim

 

Is your fuel filter clean by clean I mean no oil?

Is there any kind of contamination in your degas bottle?

With #2 being so far out it could mean an O-ring didn't set properly when the new injectors were installed which bring up my question about contamination in the degas bottle.

That will definitely cause poor fuel milage.

 

Degas bottle is clean. No diesel smell. Bottle and ELC new about 8 months ago so fuel would show up.

On the fuel filter, the pager part seemed normal but the outer "water" filter paper was black. I think this had been at least 10,000 miles.

Jim

 

Meant to stay that I think if fuel was in the degas bottle I could easily see it since both the bottle and ELC are very new. I do not see any residue on the inside of the bottle nor floating on the surface of the ELC.

Thanks,

Jim

 

Often, re-torqueing corrects the issue. Look for oil leaking at the base when started up and at 140*F. As for mileage, its difficult to speculate.

 

Thomas,

I have re-torqued. So I will start it up to see if the visual yields anything. Was wondering if something else could be physically wrong with an injector other than possibly being just loose.

Thanks,

Jim

 

As loose as you stated they were, yes that would account for noise and economy issues.

Pay close attention to the base of the injectors in the event one of the O-rings was damaged due to being loose. Also, oil should be expelled against the defector plates uniformly.

 

With one injector below 50 in/lbs - fails the go/no-go test, while the truck was still warm, and at least one other being close to the go/no-go point, it may be a very good idea to replace all of the o-rings on all of the injectors...if you have to do one you may as well do them all.

The one that was below 50 in/lbs was definitely jumping up and down in the hole on each compression stroke and getting sucked down on the intake stroke, so the o-rings on that injector could very well be toast due to friction and performing a function that they are not intended to do. Therefore, I would not simply re-torque if it were my truck.

You've already got the biggest pain done in removing the v/c's. Injector o-ring replacement is easy.

The black fuel filter is further proof....your ICP was probably lower which will cause poor atomization of fuel, which will cause a loss of power and higher EGT's etc.

You should probably test for cracks/leaks in the cups as well..a cup can be cracked and still not leak fuel into the coolant/degas bottle in the early stages.

While you are there, when is the last time that your glow plugs were changed?..less than $100 for parts - use OEM Ford ONLY.

To definitively test the injectors, I believe that bench testing is the only way. Others may disagree.

Were the injectors new or remans?

 

Thanks JHL,

Injectors are new--assuming that is what the Ford dealer sells. Ford parts dot com does not indicate that they are remanufactured. The glow plugs were also replaced at the same time. Sorry I did not note that above.

I take it that a normal fuel filter replacement will not have the outer water filter portion showing black.

I will look for procedures on checking the cups. Is bench testing the injectors something that I could do? I will read up on that as well.

Thanks for the help.

Jim

 

read up on bench testing--tells you what I know!

 

No, the outer filter should not be black. Normally, it will be a little darker than the new one depending upon where you purchase your fuel and the change interval.

"Tugly" has a thread about testing the cups. Basically, while the injectors are out, simply make sure the cooling system has enough fluid, pressurize the degas bottle and inspect each hole for the presence of water. You can use the overflow hose, a plug and nozzle.

Here is the link:

https://www.ford-trucks.com/forums/1...-stick-up.html

No, you'll need a pro. I have used Tim at P.I.S. https://www.ford-trucks.com/forums/member.php?u=764674

Link:

PERFORMANCE INJECTION SYSTEMS, LLC

There are other reliable companies as well.

If you find a cracked cup, Clay with Riffraff has an awesome rental kit/tool to remove and seat the new cups. He sends everything you need. Instructions are on the RR site.

 

Thanks! I was just reading about some of Tugly's travails with his cups.

 

I also have a good write up on injector cups as well, if you want it.

 

My ears were burning. Your first post described textbook loose injectors. The 50-pounder undoubtedly needs all new O-rings (as per the book), as mentioned. The 60-to-80-pounders were just starting to knock, but they were definitely on their way to the Whack-A-Mole game. The 60-80s were also bleeding ICP, so the O-rings should be replaced on those as well. That's not the book talking - that's my experience contributing to the conversation.

Anything above that 60-80 point is just fine. I'm sure the mechanic saw the same manual you did and set the torque to 120, but many don't give the wrench an extra "kiss" and a hot-torque. I run the engine up to full temperature (170-185 degrees F) with the VCs off, then I torque them to 125. I also get all weird and clean the bolts/bolt holes with Q-tips, brake cleaner, and air - then apply a dab of blue thread lock to the threads before installing the injector bolt. This is an extreme Hail Mary tactic, but my sticks won't stay down without the added effort.

Ford installs remans. I tried remans and hated them, so I yanked them and bought new from Full Force Diesel. Riffraff sells brand new sticks as well. 3 and 8 always pop high on the CCT, so that was not a valid test. It does sound like your injectors are good... but they worked themselves loose - a common occurrence. Fire it up, warm it up, and tighten 'em up.

Make sure you see oil coming out of each injector, but remember this: Once you've pulled a stick and drained the oil rail, #1 and/or #2 might not work at first - because of air in the rails. Letting the engine warm up helps to get the air out, but sometimes you have to put it in gear and rev it to 2000 RPM while you brake. This boosts the ICP and can push the air out of the oil rails.

 

Wanted to thank everyone. I will be working on the beast this weekend so I will revert on what I find.

Are there any suggestions for sourcing the o-rings? Since I have the OEM am I stuck with the $15 per injector that Ford quotes? I note that RiffRaff only has o-rings for the Alliant injectors.

Rich--with "kisses" and Q-tips--sounds like I may be able to get my wife to help!

Thanks,

Jim