i remember reading somewhere you can rejuvenate injectors by doing a buzz test on them a few times to knock loose anything in them. true? false?
i have the AE. is this done engine running, or engine off?

i will be sending the injectors out to Jim at rosewood diesel once spring comes and i can put the truck down for a week or so. but i need to to last for another 2-3 months.

 

The Buzz Test is done with the engine off. You can do it warm or cold. I doubt that it will improve much if the injectors are heading south. It doesn't cost anything, so give it a shot.

 

ok, engine off. that is what thought.
and i agree, it cant hurt anything.
i know i have a few bad glow plugs because it is getting harder to start.
i lost fuel mileage, it is now down to around 10mpg overall. at 189k miles, it is time to have the injectors freshened up, but i was hoping i could get the winter out of them.
i took a gamble on it because life threw a monkey wrench in my plans back in august, but i lost that bet.

 

I've personally never heard of a Buzz-Test improving injector performance. But, that in and of itself is not proof it doesn't.

If nothing else, you will get an idea of how the solenoids are performing.

On another note, if you're thinking of replacing your injectors because of a fuel mileage decrease, there are may much less expensive places to look beforehand.

I have seen these trucks with 400k and only had a couple injectors replaced along the way. But, again, I've replaced all 8 on trucks with 80k miles or less.

That being said, I would definitely determine the injectors are in need of being rebuilt before doing so. $1k - $2k expense to find out a clogged EVBP tube is clogged in the end would be excessive to me.

 

How many miles on the engine/injectors?

 

I would think that doing it on a warm engine that you would have at least a little bit of fresh fuel in them for lubrication reasons if nothing else. Some time back I saw a Y-tube of a guy that made his own "Buzz box" to put his injectors through a "workout". He fried all of them due to no lubrication from the fuel.

 

I found that the most 'accurate' time to do a buzz test was stone cold. My so called 'reman' injectors failed a cold buzz test everytime. Engine would hardly run until it was warmed up.


I've learned my lesson. I will only buy new injectors from here on out.

 

189k on the engine. it was maintained before i got it, but not to my standards.
Jim only charges $500 plus parts to rebuild injectors, unlike the others that charge $1500 plus.
i know there is issues with them, i get a flutter until the engine is fully warmed up.
there are 2 that did not sound the same when i did the buzz test. and i did it warm, 145º engine temp.
i trust Rosewood Diesel. Jim has a very good reputation, and makes sure everything is rite before sending them back..

 

A buzz test is done koeo (key on, engine off). It only fires the solenoids. Without high pressure oil, the the injectors aren't actually firing, so fuel lubrication is a non-issue.

 

I didn't have the same luck with my 'vendor'.....

 

Buzz Test should be done COLD for the most accurate results. If there is a weak one you'll definitely hear it then.

IMO $500 is a good deal with his reputation. Certainly beats the $2,500 for 8 new. A guy stopped by and said he paid $2,500 for parts and labor for one injector and an oil change on his 6.4 from the Dealer over Christmas.

Might want to think about doing the cups when they're away for a few days as well. No use in going back in later.

The two biggest things affecting injector life span is fuel and oil. People think I'm crazy when I unhook the 30' Enclosed Car Hauler and find a Jiffy Lube when we travel. And, I carry the Filters (Oil and Fuel FoMoCo) and watch them add the Rotella to make sure.

 

i would junk a vehicle before ever bringing it to an lube rack manned by people that are dumber than retarded monkeys

 

That's why I watch them.

Ironically you mention the retarded monkeys. The dumbest I ever came across was in OH, I think it was a "Penzoil Lube". The kid bent, beyond any future use two filter wrenches trying to get the filter off until I said "That ain't goanna work" and gave him mine to use.

If I thought I could get away with dumping 15 Qts of Oil in a parking lot I would. As it is I leave some fuel when I change the fuel filter in parking lots.

 

Doing a buzz test is nothing more than operating the solenoids the same way the IDM does at about freeway speed - you just don't have fuel, oil, and movement (compression) to join in on the festivities. A buzz test can actually be hard on the injectors, because you are cycling poppits without lube flowing through them - but there is residual lube in there, so the buzz test is kept short to take advantage of this. If you sat in your driveway and said "I think I hear a bad #6, do it again" all day, you would run the risk of introducing substantial miles worth of wear on the poppit valves. I record mine for documentation and later review.



The fuel half of the injector sits like a bump on a log... well... more like a piston in a cylinder. The poppit valve does nothing more than let ICP into the injector... it's the ICP flooding in that actuates the bottom (fuel) half of the injector. The HPOP makes ICP with the engine spinning, which ain't hap'nin' during a buzz test.

One of the deadly sins to kill an injector prematurely - air in fuel. I got a piece of this and I'm still cleaning up the mess. Many talk of air in fuel effecting #8 cackle. I have the FRx, and I had a vacuum leak in my fuel line before the prefilter. The air didn't accumulate at #8 and #1, the FRx took care of that. However... #2 and #7 got fist dibs on any air that made it as far as the fuel rail - and they took it all.

tjc transport - I would focus more on the ICP/IPR/FIPW/RPM combination, along with the Torque Converter Slip. You may have something as simple as bad O-rings or a slipping torque converter.

 

there is definitely nothing wrong with the torque converter.
it is solid when in lockup.
EBPV tube is partially clogged, AE says EBP sensor low or something to that effect.
the problem is in the injectors and glow plugs. i know this.
it has two bad/weak glow plugs. it will not easily cold start under 30 degrees unless i plug it in for an hour or two.
the engine has a slight miss when cold, and you can hear that 2 injectors do not sound the same during the buzz test. once the engine reaches operational temps, the flutter goes away.