Fuel Injector Not Working. How do I find the bad one? Need help!

[BTR]

@410Fortune - Roger that and thanks! Appreciate your reply.

Yes... it's a PITA to do the fuel injectors... AND then have to go back in to address a vacuum leak! To confirm a vac leak, I'm going to do the "starter fluid" test first. This, along with the surging, no CEL, and the stethoscope test (injectors passed) will help me feel confident that a vac leak is in fact the issue. If so, I'll do the lower intake gasket, the EGR tube gasket, drill out the upper manifold per Donalds, and make sure all hoses fit snug.

I did the upper intake gasket late last year... at the same time I was doing the tensioners. I did both tensioners then.

If it still idles rough after all of this, I'll pull some more OBD data and go from there. Thanks again.

 

[Motorhogman]

@410Fortune - Roger that and thanks! Appreciate your reply.

Yes... it's a PITA to do the fuel injectors... AND then have to go back in to address a vacuum leak! To confirm a vac leak, I'm going to do the "starter fluid" test first. This, along with the surging, no CEL, and the stethoscope test (injectors passed) will help me feel confident that a vac leak is in fact the issue. If so, I'll do the lower intake gasket, the EGR tube gasket, drill out the upper manifold per Donalds, and make sure all hoses fit snug.

I did the upper intake gasket late last year... at the same time I was doing the tensioners. I did both tensioners then.

If it still idles rough after all of this, I'll pull some more OBD data and go from there. Thanks again.

When I was looking for a vacuum leak I did the propane, starter fluid and carb cleaner tests. Couldn't locate it. Made a smoker from a cheap HF transfer pump (per suggestion of member in here) and found it to be the vacuum line that runs down the front of the engine to the EVAP system solenoid under the battery box.

 

[BTR]

@Motorhogman - Yep... sure enough... like you, I did the starter fluid test this morning. And, surprise-surprise, the RPMs didn't change. So at this point, I'm going to replace the gaskets, reassemble everything, and then pray it runs smooth thereafter. I like my truck... but sometimes she's just a lot of work... especially when it come to diagnosing problems. I can pretty-much repair anything. However, diagnosing problems can be quite, stupendously challenging.

 

[410Fortune]

I have never ever not once had luck finding a leak with starter fluid on these trucks not once
Smoke test only! Or I just Re seal the top end on any old engine, all of these engines need new intake gaskets at this age, the o rings simply do not last this long

 

[BTR]

Can anyone tell me what the pattern for tightening the lower intake manifold bolts is? Is it inside-to-outside... or outside-to-inside... which one? Many thanks.

 

[donalds]

Can anyone tell me what the pattern for tightening the lower intake manifold bolts is? Is it inside-to-outside... or outside-to-inside... which one? Many thanks.

Always inside to outside always use this as a rule of thumb

 

[BTR]

Got it! Thanks!

 

[BTR]

Well. It's not a vacuum leak. I gasketed everything up and triple checked all connections. It starts, idles, and is driveable. However, it's rough.

Something is intermittently and consistently cutting in and out. The cut out matches the RPMs. At this point, I (think) I'm back to focusing on the refurbished fuel injectors, i.e., one of them is bad. Even though all 6 are clicking the same as each other, my best-educated-guess is that one is clogging or over injecting.

The STFTs in Bank 2 are crazy-different than in Bank 1. Bank 1 looks normal. Bank 2 is all over the place... with high and low numbers.

Anyone have any thoughts? I appreciate it.

 

[410Fortune]

Check oil does dipstick smell of fuel?

 

[BTR]

@410Fortune - Yes, the oil dipstick smells like fuel. What's this mean? Thanks.

 

[donalds]

@410Fortune - Yes, the oil dipstick smells like fuel. What's this mean? Thanks.

Meaning fuel in the oil

Leaking injector ....one stuck open maybe

Wish you would have just cleaned your old ones

 

[BTR]

It's taken me 2 years of observations and diagnostics to "determine" that my no-start-the-first-time after sitting hot is being caused by a leaking injector... not a clogged fuel filter... not a bad fuel pump... not a bad ECT Sensor... nor whatever else. Thus, I decide to replace the fuel injectors... thus, creating all this extra work... thus, driving me crazy... thus, it (might not) actually fix the no-start... thus, thus, thus!!! I'm having waaaaay tooooo much fun!

 

[donalds]

I wish I was closer I'd come fix ur truck happily
Keep at it ur almost there

 

[410Fortune]

Okay so fuel in the oil because you have a sticking injector that is likely stuck wide open

This means every time you fuel pump comes on the injector is just dumping fuel

To find which cylinder pull the plugs on bank 2
The gas washed plug is the culprit cylinder

You will need to change your oil at least once if not twice you do not want raw fuel in crankcase it will wipe out your crank bearings

 

[BTR]

Okay so fuel in the oil because you have a sticking injector that is likely stuck wide open

This means every time you fuel pump comes on the injector is just dumping fuel

To find which cylinder pull the plugs on bank 2
The gas washed plug is the culprit cylinder

You will need to change your oil at least once if not twice you do not want raw fuel in crankcase it will wipe out your crank bearings

Roger that. I've got 3 more fuel injectors coming Monday or Tuesday. No charge and free shipping from the vendor. I'm going to replace all 3 in Bank 2... and go from there. What's the good news? I can now take this thing apart and put it back together easy-as-pie! And, everything in there is now clean, so swapping out the 3 injectors (should be!) not too hard.

After that >>> oil change and monitoring the no-start-the-first-time after sitting hot situation, which I HOPE will be fixed by the refurbed injectors.

 

[Mbrooks420]

I’d clean the new ones first.

 

[410Fortune]

“cleaning” them means you will actually see them open and close and spray fluid before you install them… this step saves us from installing bad injectors

 

[Mbrooks420]

I’m always skeptical of regular parts. Plus, who knows how long they’re sitting.

 

[410Fortune]

I had good luck with reman injectors off eBay until the last set… then I had one that was stuck open. I just went though this same thing. “Reman”’is only as good as the person doing the work… so it helps to check seller ratings and all that, but at the end of the day most times it’s easier just to refurb our own stock units or at least test then new remand before install

 

[BTR]

Testing / cleaning / refurbing my own OEM injectors is an interesting topic. What tools are required and how does one go about doing this? I've watched videos in which a large "cleaning system" is used. It has clear windows through which you can see the injectors spraying. I'm not sure I want to buy this system. Thus, what's the "DIY" way of refurbing injectors?