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Suspected dirty injectors

7K views 57 replies 9 participants last post by  bluenavigator 
#1 ·
After sitting in my driveway for almost 2 years, I am going to change oil and check few things. I think that the injectors might be dirty. I am considering using SeaFoam as additive in fuel. Is it good or is there another recommendation to use to clean the injectors, other than taking the injectors out to be cleaned by the shop?
 
#2 ·
Personally, I like Hot shots secret once every 6 months I put in the stiction eliminator. I currently have 200,000mi. on this set of injectors and they don't skip a beat truck runs great.
 
#3 ·
Yea, seen some of them at Tractor Supply Company. Must be good stuff.

The reason why I am thinking of the injectors being dirty, the engine does idle just fine, sitting in the driveway. When I drive the truck around the streets or down the highway, I can feel the engine kinda of stumble or not at the full power. I mean that there is noticeable loss of the power. It only happen during high RPM, not low RPM, which makes me think of injectors being dirty somehow.

I had replaced the o-rings on all 8 injectors with "updated" o-rings for new ultra low sulfur fuel, maybe 14 years ago. I got them at International dealer. $20 bucks per set for each injector.

Wonder if there is another possible cause of this... IPR? That one was never replaced. I do not know if it goes bad or not. How does one determine that IPR was bad or not?

I had the fuel pump replaced about 14 years ago because it leaked at the weep hole. I checked it while it was out, I am able to push the tappet (not sure what it was called) and it pump the fuel out as expected.
 
#4 ·
I would think a dirty/poor working injector would show problems at all RPM's. It wont hurt to run some cleaner of you choice, but, I would clear all the codes then drive a bit and see what they show. I would suspect the under cover harness or fuel delivery (pre injector) problem.
DENNY
 
#6 · (Edited)
I would clear all the codes then drive a bit and see what they show. I would suspect the under cover harness or fuel delivery (pre injector) problem.
DENNY
My truck is not exact OBD II compatible (maybe wrong word but...) - I can plug OBD II scanner but it wouldn't read/pull anything. I think that I need it to be reflashed or have correct scanner that can read OBD for PSD only. That's what I believe. :( If anyone have good scanner that can read the codes, please let me know. For my scanner, it is INNOVA 3130c "FIX Assist ScanTool w/ABS."

If a truck sat for 2 years I would be concerned about condensation having gotten into fuel and possibly microbial growth.

If you’re only experiencing this issue at higher RPMs, have you considered a dirty fuel filter? What does it look like? If you haven’t drained the fuel bowl on a truck that sat 2 years then I would drain it into a clear glass jar.

I would do this after driving it long enough to transfer fuel from the tank into the fuel bowl.

And post the picture if you get a chance.
The fuel bowl was pulled already as I replaced the fuel lines and fuel regulator screen and ball. The screen fell off when I opened the fuel regulator on the fuel bowl. The filter was medium brown, which I know that it is not good anymore.

I had replaced air filter, oil filter and oil. For the fuel, I would like to believe that it had 4 gallon remaining. I just had it filled to full, mixed with SeaFoam and Power Service "Clear-Diesel." Will drive my truck around for a while and pull the filter and see if it get dirty or not. I drove only maybe 4 miles after refill.
 
#5 · (Edited)
I would use a BioDiesel product like B20 before SeaFoam. I think HotShot is great for 6.0 stiction but I would run a diesel specific treatment by Power Service that removes water and also be prepared to add one that is a biocide.

If a truck sat for 2 years I would be concerned about condensation having gotten into fuel and possibly microbial growth.

Ofcourse, if you live in cold climates it might be hard to find B20 this time of year.

If you’re only experiencing this issue at higher RPMs, have you considered a dirty fuel filter? What does it look like? If you haven’t drained the fuel bowl on a truck that sat 2 years then I would drain it into a clear glass jar.

I would do this after driving it long enough to transfer fuel from the tank into the fuel bowl.

And post the picture if you get a chance.
 
#8 ·
#9 ·
Have been driving my truck for couple days. I noticed that it shakes when I got up to 40 MPH then keep shaking until 45 MPH. Then It goes away as I go up over 50 MPH. I am able to drive at 60 MPH with no shake. I watch the tacho. I didn't go over 2250 RPM. Then at every red light, I started over and watch everything going on. After this, I suspected that it is not injectors at all.

Right now, I am suspecting bad tires as they could be out of balance. One more thing to think about... driveshaft. Anyone experience bad driveshaft or that it went out of balance?
 
#10 ·
Tires, and U-joints are the first things I would look at. I have several u-joints go over the years. Had a tire come apart last summer took out the driver side fender.
DENNY
 
#11 ·
How long are those U-joints supposed to last? Last night, I replaced all three u-joints with the ones with the oil fittings installed. Drove around a bit. Shaking is still there but much less... Next stop - tire shop to do the balance all four tires.
 
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#12 ·
After driving my truck for a while, on way to my work, which is a good 16 miles, ranging from stop to 55 MPH, shifting through. With the shaking going on, I am starting to think that it is the clutch going bad. Is it possible that clutch go bad after long sitting in the driveway? It used to have dual mass flywheel. Replaced it with LUK setup in 2004.
 
#13 ·
I don't think sitting would hurt it.
DENNY
 
#14 ·
Your tires have all passed an inspection and been re-balanced at a shop since you started driving it again?
 
#15 ·
For the state inspection, they only checked the thickness of remaining thread. I hadn't get the tires balanced yet. I am going to do that this weekend or next.

Oh, you mean the tire shop do the inspection on the tires? Doh! My bad!
 
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#16 · (Edited)
I have always used Discount Tire for my vehicles and when they balance a tire, they perform a thorough visual inspection while its on the machine. Especially if you mention the truxk sat for a couple years. No doubt they have a business interest in finding damage but I bet they have saved alot of roadway blowouts and lives with this practice.
 
#17 ·
Got my tires inspected and balanced. Only one went bad, need 14.5 grams lead. That tire was trashed. Drove my truck again. Guess what? Shaky gremlin is still there. *sigh*
 
#23 ·
Well you are still better off to have had the work done and eliminate one more possibility.

So here is a thought, have you driven the truck in various gears to determine if the vibration is speed related or RPM related?

Agree that a carrier bearing could be worn out. They should be snug and not sloppy when gripping and shaking the driveshaft by hand.
 
#18 ·
I had a set of tires that gave me a vibration no matter how they were balanced. If a certain tire was on the front I would get vibrations at 50-60mph, if it was on the rear the vibration would show up between 70-80mph. I loved it when I got rid of them.

So, have you had your drive line checked to see if it is balanced, checked U-joints? No bent axle?
 
#19 ·
The tires, after being balanced, were mounted back to opposite corners/sides as rotated. The shaky gremlin came back at same speed range. I have replaced all three u-joints. The drive shafts wasn't checked but from visual check, I do not see anything that showed something being off or that they were bent at all. The only thing that was bent is the spare tire carrier as it was bent when it was not put up while driving backward. My mistake. I can take it off and have it fixed later but doubt that it has anything to do with the vibration but it wouldn't hurt to have it removed and see if anything is different.
 
#20 ·
The drive shaft doesn't need to be bent but can be out of balance. If you look at a lot of them you will see balancing weights attached to them
 
#22 ·
How's the carrier bearing? Not that I know (and maybe somebody here can chime in), but don't the sections of driveshaft need to be "phased"? Cheers!
 
#24 ·
Well you are still better off to have had the work done and eliminate one more possibility.

So here is a thought, have you driven the truck in various gears to determine if the vibration is speed related or RPM related?

Agree that a carrier bearing could be worn out. They should be snug and not sloppy when gripping and shaking the driveshaft by hand.
Yes, I had the mid-section carrier replaced once back in 2000. I didn't feel anything from that one. Someone mentioned to check this part back in 2000 on this forum, under different name (pre-thedieselstop). From that, I just went up and checked it out. Sure enough, that it is really loose, not snug at all. Had hard time take it out but put new one on, it is smooth sail.

Today, I am going to attach GoPro cameras and monitor the under carriage.

Side note: I am deaf, which poses another problem, unable to hear certain noises, necessary to diagnose the whole thing.
 
#25 ·
Update: I had my friend ride with me. He suspected flywheel being unbalance. Oh great...
 
#26 ·
I would look other than the flywheel. I don't think I have ever seen a post about that being a problem.
DENNY
 
#27 ·
If you had the dual mass flywheel, that could be a possibility if it puked a spring out. But the thing is about a flywheel being out of balance, is it would be evident at all speeds, even when sitting still. It's possible that it could amplify at certain speeds/engine rpm's because of harmonics, but I'd be doubtful it's the flywheel. It can easily be tested by revving the engine while sitting still.
 
#28 ·
Yea, I had that experience before replace it with LUK.

Just few minutes ago, my hearing daughter rode with me. She said that it is nothing from transmission. However, there is subtle knocking noise, more from the front around tires. It is not loud but it is there. My next guess is to check the bearings and spindles. That is better than pulling the transmission for sure!
 
#29 ·
If you have already replaced u-joints in the front axle then possible bad wheel bearings?

I feel like I am just throwing darts at the wall at this point.
 
#30 ·
Your last dart (front axle u-joints) missed by a long way. :winking:

Notice in his signature he has a 2WD truck.
 
#31 ·
Your last dart (front axle u-joints) missed by a long way. /forums/images/TheDieselStop_2015/smilies/tango_face_wink.png

Notice in his signature he has a 2WD truck.
I think I hit myself in the forehead with that dart.
 
#32 ·
I think that I found the culprit. I worked on the front passenger rotor. I can see outer bearing being seat nearly firm. I took out the cotton pin out and removed nut retainer off. Easily, I took the rotor off. I do not see anything wrong. I decided to check the inner bearing, it seem to be very loose, which I was expecting it to be tight, not all over the place. Only I think that I need special tool to pull the inner bearing off from the rotor itself.

After checking both inner and outer bearings, they seem to be okay and repacked and put back in the rotor. It seem to be tight. So it is not the culprit as thought in first place. While I am at it, I am going to check the shock absorber to see if it is still good.

After checking the shock absorber, it was shot. It would not go back up.
 
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