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Discussion Starter #1
i kno bad injectors can cause some serious harm to an engine but based on a lot of reading and some help from u guys on the forum :thumbsup: ive determined that one or more of my injectors has a high return rate. my questions are can this lead to those horror stories of wrecked cylinders and new engines? how long can i go before i need to address this problem?

i have no diesel in my oil, no white smoke on start up, and the truck sounds good and feels good while driving. the only issue is long cranking when cold outside to build pressure. since its summer now that wont be a problem til about october. i am planning on buying new injectors but they will be 50hps or 90hps and i wana upgrade my trans, and fuel pump before i do so. u guys think i can ride this out a few months or what?
 

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I am no expert but... try this asap if you think you have a clogged injector or two...

http://www.cumminsforum.com/forum/3rd-gen-powertrain/274704-diy-seafoam-treatment.html#post2926296

I did this 3x and motor runs awesome, no more excessive timing rattle (all but gone really) under part throttle conditions. MPG did drop however which makes sense... clean injectors flow, dirty injectors will increase fuel return volume to the tank (== better mpg... IMO).

I also had no diesel in the oil, white smoke or any other issues other than bad timing rattle @ part throttle.
 

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Discussion Starter #3
thanks man mayb ill give it a try ive been hesitant to do so because i dont like the idea of running seafoam through my motor because its so much dryer than diesel.

whats weird is my mpgs have been slowly dropping for like a year:confused013: not getting better. what u said about the return to the tank makes sense though.

so do u think i can harm my engine by not doing something right away?
 

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IDK, I'd wait for an expert to chime in... doing the seafoam treatment like I did should be OK because the stuff is not in the motor but for a 10~15 minutes at the most (if even that). It is not like your running it thru your tank which is NOT recommended by the experts.
 

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Discussion Starter #5
yea good point ive read about enough people doing it so mayb ill give it a go
 

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Like I said, 3 times & timing rattle was reduced to next to nothing, really hard to tell it was there if at all. The 3rd time was overkill IMO now that its done, I did not hear much if any change from before & after the 3rd time.

The key's are to make sure your motors up to opp temp and go hammer on it after you've finished the heat soak cycle... 1st time I noticed allot of grayish smoke when I was romping on it, it diminished as the romping continued. 2nd time, not so much, 3rd time... normal black smoke only.
 

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how do you know your injectors have a high return rate? and why is this bad?

thanks, just trying to learn.
 

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If they are not flowing 100% of their capability, the excess will get dumped back into the tank. For me, after the seafoam my mpg went back down to what I used to get, rattle was gone, more black smoke out the back, motor runs perfect.

I believe the test is to measure the amount of fuel that is returned to the tank in a given time period given a known fuel rail pressure... I think for this test to be accurate you'd need to know the flow of the injectors at the rail pressure they are seeing & how much fuel should be returned in that given time period.
 

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if your injectors are letting more fuel to the tank your truck will be getting harder and longer to start. when the do that it doesnt mean the nozzles are going bad but the bodies are. when the injector starts dumping more fuel then necessary into the cylinders and your seeing black smoke high egt's then it will kill your motor if you dont take care of it right away. seen it up close and personal in both problems
 

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rpage, how do you know if an injector body is weak or not? with my truck, rail pressure is good at idle & at speed, no starting issues and the smoke I see is what I'd expect using the smarty on #5.

If I put the smarty down to 0, then it should not smoke at all if there are no issues correct?

I am beginning to wonder if the injectors that are "weak" are being mis-diagnosed and are actually dirty. I read allot about how it is recommended to look to swapping injectors at 120k miles or so and I'm wondering if they are just getting so clogged that they cant work right. One of mine was dead silent before I did the 1st seafoam treatment, after it was clicking away as expected.
 

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I have done this Seafoam treatment on my truck since day one. At least once a month I will run it through the filter before a long highway drive. I had my injectors with 115,000 on the clock tested last week and every single one of them tested perfect. I know people with less than 100,000 on their truck have injector problems. Heck I have heard of few people that had their injectors tested after 100,000 and they all checked out good. How could you explain that? Seafoam does its job!
 

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I have done this Seafoam treatment on my truck since day one. At least once a month I will run it through the filter before a long highway drive. I had my injectors with 115,000 on the clock tested last week and every single one of them tested perfect. I know people with less than 100,000 on their truck have injector problems. Heck I have heard of few people that had their injectors tested after 100,000 and they all checked out good. How could you explain that? Seafoam does its job!
i got 160k on mine...and zero signs of injector failure or wear. or at least i think. :hehe:
 

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Master of Mayhem NASFIG
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the only way to tell if the body is weak is by a flow test. but yea if you are not seeing smoke then the nozzles should be fine. run some cleaner thru it cuz these injectors will get dirty espicially if you dont tow heavy or a lot
 

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i was looking to buy an 04 but the owner is telling me all the injectors are bad is it possible for all the injectors to go bad at once or am i going to get this truck for a deal run some sea foam through it and be all good?? just trying to learn some.
 

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Discussion Starter #15
how do you know your injectors have a high return rate? and why is this bad?

thanks, just trying to learn.
when its 50 degrees or below outside my truck has a sporadic hard start and takes five seconds longer to build rail pressure. at 30 degrees or below it takes more like ten seconds of cranking to start (when the engine is also cold) it sounds like the injectors are starving for fuel like on the first start after ur fuel lines/injectors have been drained.

besides this why is it bad? thats my question also:hehe: im still learning too thats why i posted originally about what i could be harming. like said returning too much fuel to the tank means ur engine isnt running like it should be
 

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Discussion Starter #16
the only way to tell if the body is weak is by a flow test. but yea if you are not seeing smoke then the nozzles should be fine. run some cleaner thru it cuz these injectors will get dirty espicially if you dont tow heavy or a lot
so r u suggestion the seafoam treatment too? the only injector issue i have is the long cranking to build rail pressure and thats only when its cold. i would like to get them folw tested though can i do it with them in the engine or do they gotta come out
 

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Discussion Starter #17
if your injectors are letting more fuel to the tank your truck will be getting harder and longer to start. when the do that it doesnt mean the nozzles are going bad but the bodies are. when the injector starts dumping more fuel then necessary into the cylinders and your seeing black smoke high egt's then it will kill your motor if you dont take care of it right away. seen it up close and personal in both problems
ok this is kinda what i was getting at in my original question so its time for another ha.

the injector dumping fuel into the cylinder, and the high return rate causing fuel to be sent back to the tank are two different injector issues? the return rate problem may be because they r dirty and need seafoam treatment and pose no severe threat to the cylinders/engine? and when they dump fuel is when injectors are bad or have failed?(this is serious i kno) i dont have the symptoms of the injectors dumping fuel into my cylinder
 

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i got 160k on mine...and zero signs of injector failure or wear. or at least i think. :hehe:
Do you do anything weird like run 2 cycle oil? Or do you just put in pump diesel and drive it?:party018:
 

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you just dump seafoam into the gas tank?

i've done a treatment on my tahoe but i sucked the stuff into the engine using a booster hose (something like that).
 
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