Hey everyone,
I currently have my injectors pulled due to the dreaded o-ring deciding my fuel side of things needed some extra lubricity (Got a set of eight Motorcraft O-ring kits for $20 from a buddy that was extremely generous). I am curious to see if anybody knows who can test our HEUI injectors. My local Mack shop doesn't have the hookup to do them and has to send them down to their Greensboro, NC facility to test them to the tune of $60/injector.

The reason I am wanting to have the injectors tested is I have found that two of them have been replaced with reman units (10/14 and 1/15 build dates) making me question the health of the rest of the injectors. On one of the injectors the o-rings were pretty bad, with the exception of #8 as it was one of the remans. This is what #1 injector looked like:


Almost all my other injectors looked about like this:


This tells me my fuel o-rings have been leaking a tad bit (cap discoloration). The main reason I am partially reluctant to go ahead and o-ring the injectors and throw them back in is that I don't want to go through the process on an injector that is going to be going out on me in another week or two. My other options are to get a whole new injector set or to get Rosewood to rebuild mine.

Thanks for any bits of advice you all can give me.

 

My advice would is to send them to rosewood if you have the coin because chances are those sticks of yours are well used and you can get a few more horses and gain a piece of mind.

 

The facility here in Austin wanted $100 per injector to test when I asked two years ago. I passed on that offer.

 

There is a very high chance #8 and #3 injectors are remans, because the grey Cam Position Sensor gives a false CCT fail on those two, and most alleged mechanics today trust whatever the computers tell them - no matter what their ears and eyes say.

How many miles on the sticks? How have they been treated over their life in terms of fuel lubricity and oil changes? Have you had any symptoms other than oil in fuel? What are the goals for your truck - more power? How comfortable are you with throwing down over $1000 for preventative maintenance?

 

I hadn't even considered that being a reason they were changed out as I had the false fail when I first got the truck.

The remans have about 25k on them, while the others I presume are all stock, meaning they have 367k. I was told the truck originally belonged to a logging company, but no paperwork to back the claim up.

Since I have owned the truck I have religiously changed the oil every 5k, and just this past change started analysing the oil. I have ran primarily 50 Cetane diesel from Southern States, and when heading North I used BP.

Main goal is to have as reliable a vehicle as possible, and eventually get 400-450rwhp.

As far as money is concerned, I would be comfortable shelling out the money to keep the truck going if it wasn't sitting in the body shop at the moment. The truck is at a perfect spot to get completely repainted (~1800 to finish the side insurance isn't covering), but a pretty truck doesn't get me home at night.

I also don't want to put o-rings in, get the truck painted, then turn around a week or two later and have to pull the injectors again. A couple of the holes in the nozzles were completely shutoff, making me lean toward either rebuilding mine or a new set being my best bet.

Despite all my diesel experience, these HEUI systems are unmarked territory for me. I know how they work, but as far as being able to tell how one has been operating the entirety of its life is foreign to me.

 

At that many miles a set of NEW injectors would be in order if the $$$ permits.

 

Here's the tricky part: If the ultimate goal is 400 HP, that takes stage II sticks and aftermarket tuning - and a bigger turbo - and bigger exhaust - and a bigger intake - and an upgraded transmission - and traction bars - etc....

The key point is if you want to eventually power up, step one would be to injector up and tune them down. Once you've added all the other components to digest the fuel, then you can ramp up the tuning. The Hydra allows for emailed tunes, so having one of those with your new big sticks gives you options.

There is an injector link in my signature that covers remans vs. new. I did both... no more remans for me.

 

I am guessing by the look of that one O-ring in particular you had a bit of a miss. With that said I would run them with new O-rings till you have a real failure on an injector. As long at you have them out you may want to look at doing the shim on the top under the solenoids. This will give you a real good indication of wear. As they need shims as they wear down.

 

Ended up reading through that whole thread today, lots of helpful information in there. When I do go for a set of injectors, I plan to go with new, modified injectors and possibly send my injectors to Jim at Rosewood for rebuilding to have as a spare set in the event something happens to the set I bought. I plan to go back through that thread again to ensure I have gotten every bit of valuable information it has to offer.

I did have a miss at cold (smoked a tiny bit for about two to three seconds and cleared up) right before the dead miss began while letting the truck warm up. I had been thinking about shimming the injectors due to how many miles they have accumulated, and as you indicated, now will be the perfect time to do them. Would it be wise to take a brass brush or a scotch brute pad to the surfaces on the injector/nozzle to help remove the buildup on them and have a good mating surface for reinstallation?

I do wish that there was a facility that was able to test our HEUI injectors that didn't cost almost half a set of injectors as I would be interested to see how they perform before and after the shimming. Wish they were as simple to test as the old IDI injectors are.

 

Spares would be nice, but you'll need some cores to send in for the new injectors.

 

I bought 1 spare new injector, since my type of injector won't be sitting on a shelf on a national level (like a stocker would be at Ford, CAT, or IH). This has served me well for swapping if I want to isolate a problem.

 

IIRC, you've swapped in the 9th stick a time or two. Was it a cure to whatever symptom Stinky had and if so, were you able to send it in and find out what the failure was?

 

That is true, I forgot that Alliant requires cores on even new injectors. I believe I will do what Tugly did when the time comes and get a ninth injector to have at the ready vs a whole set sitting. Cheaper, and the extra security to boot.

Out of curiosity, does anybody know if shimming an injector would cause a rebuilder to not accept it as a core, or am I over-thinking things?

 

I can't see why shimming the poppet would cause the injector to become unusable as a core.

 

What I was thinking that could happen is increased poppet seat wear, resulting in the injector having too much wear to be used. I do believe I am over-thinking that part.

I popped open my #1 injector and found it to be a snug fit on 0.0025," and a nice loose fit on 0.0015", leading me to believe the clearance is around 0.002" resulting in the shims being a viable idea.

On another note, I believe a title change may be in order, seeing as the thread has gone from asking about injector facilities to you all helping me decide if running my injectors longer or getting new would be best.