On the early 3412 HEUI motors, the original injectors are no longer available. I've been told that the new style injectors have a check valve in the oil return line so that the oil will not run out, resulting in hard starting after setting for a week or two. Is there any other way to solve this problem,besides replacing all the injectors? With the cost of new injectors, changing out all 12 is quite cost prohibitive, but this motor, after setting for a week or two, will not start at 40 degrees and this is what Cat says needs to be done. Any ideas?
I've heard that a can of aerostart was the weapon of choice for the cost savy maintenance
Non-Prime Squirters were the ONLY good thing about a HEUI....don't rob yourself of that!
What model of machine is this engine installed in and what Part Number of injector do you have installed right now..? Also how many hours do the injectors have on them..? The only difference I am aware of between the 2 types of HEUI injector is that the early design (Prime-type) injected fuel in 2 separate stages, the later ones (Non-Prime type) injected all the fuel in one hit. I have heard nothing regarding about an internal check valve being added. The change of injector from Prime to non-Prime was made about the 2003 time frame. I find it hard to believe that any Prime-type injectors would still be in an engine 10 years later, they didn't last that long......... 10 months would be more likely....!!
Remove the Tappet covers and watch the Engine start COLD. Soon work out which Squirter type you have.
Better still, remove the tappet covers and read the Part Number off the injector ........ :tong
No matter what type of injector you fit, starting is still an issue after a long lay up. Especially if the engine application means the engine sits high at the front ie marine. The best and cheapest cure for this is to fit a pre lube pump.
A prelub pump won't make a ha'porth of difference on a HEUI. If during cranking the hydraulic pressure in the system (Actual Injection Actuation Pressure) does not get up to the value that the ECM wants (Desired Injection Actuation Pressure) then the electronics will sulk and refuse to play. Result is no smoke from the chimney and no start. Oh how I thank my lucky stars I don't have to work with 3400 HEUI engines any more ..........
A prelube will fill the HEUI pump with oil before cranking. We have had good results with this in marine applications where the engines sit high at the nose and the oil drains away from the HEUI pump very quickly. The first time we came accross this issue was in a Life boat, CAT sent me out to tell the customer he had to remove the oil line leaving the pump and pour oil in to prime the pump and start the engine. As you can imagine the customer was not happy with this advice.
I can only comment on machine engines but the prelub pump seemed to make no difference whatsoever to cold starting performance. The added difficulty was that due to the lack of space the prelub pump was integral with the starter motor and burned up with monotonous regularity.
This engine is in a Morbark tub grinder, not sure of the year. I may be in the area tomorrow and will try to check the engine numbers. I was considering whether a prelube pump would work. When cold and having not run in a few weeks, this thing will crank out the smoke but even with a bit of aerosol assistance it will not run until the outside temp rises. Once started it runs fine.
Tub grinder hey, check the tubgrinder hydraulics are not loading the engine prior to it starting, have seen auxillary applications like this where there is a slight hyd load on the pumps which cause the cranking speed to be off by a bit which then inturn don,t allow it to fire.
Try manually filling the HEUI pump with oil. If this works, the prelube will help. For sure if there is any sort of load on the engine it will struggle. How many starter motors are on the engine ? We find they need 2 for the winter.
We had major issues with HEUI engines in the Andes. A combination of 10,000ft+ altitude and temperatures low enough to freeze the nuts off a polar bear meant they were very reluctant to come out and play starting from stone cold. As other posters have mentioned the key is often the engine cranking speed. If you can get to 150 RPM on the starter motor there's a good chance that the engine will fire up. However even at high RPM on the starter excessive leakage at the injector poppet valves is your enemy. If the leakage from the 12 injectors is more than the HEUI pump can supply the rail pressure will never get high enough for the electronics to come out and play and the engine will never fire. Excavator - get the engine Serial Number if you can. Also if you've got mechanics on site pull one of the valve covers and read the Part Number off the injectors. It will need a small mirror to do this because the number is hidden down the side. Another clue - if it's smoking out of the chimney then the electronics are playing and you are getting fuel. That means the HEUI system is getting enough pressure to activate the electronics. I would hazard a guess that your problem is not necessarily the HEUI Pump or the injectors. Maybe an external parasitic load when cranking as others have suggested.
How many hours are on this engine? The usual issue I've seen on tub grinders is constant overload, violated air filters and the big potential of overheating makes for loss of compression into the crankcase. As Nige says "if it's smoking out the chimney then the electronics are playing". Take a look at the ends of the breather tubes and if they are covered in lots of oily dirt your problems may be only just getting started.
Hello! I'm a new member and am desperet for some answers. so please if you know , HELP. I have a 3412E 4CR engine 980Hp. The injectors are falty. now as they are wery expencive I wass lucky to find the reman injectors at wery afordable price. The original injector number is 174-7529, and the reman ones are 174-7526. My question is: what might bee the diference between them and will they work on my engine. Please help.
174-7526 Part Number of HEUI injector is for a 3400E machine engine, not an industrial engine like you have. These injectors will not work in your engine as far as I know. 174-7529 (replaced by 174-7528) is the correct Part Number for your engine. Also my experience is that Caterpillar gave up trying to remanufacture HEUI injectors many years ago because of the failure rate on Reman injectors. I would be very suspicious of any aftermarket provider that is suggesting they can successfully remanufacture HEUI injectors.
These ara cat reman. the number 174-7528 does not aplie with this engine. When you say it wil not work , do you meeen that it want start at all or?? what is the main diference betwene the two injectors, couse they look exsactly the same from the outside. The thing I know 100% is that the hydraulic part of the injectors is the problem in my case. I have disasembled them number of times and the nozle part is ok. the problem is in the hydraulic valve and the internal seal of the intensifier piston. my question is the hydraulic part the same on both injectors. my idea is to put my nozles on the new injectors. what is your opinion on that. the price of naw injectors is uncomparable with the ones i can get. that is why I'm wilng to try this. tel me what you think please. Thanks for the first replie and sory if the speling is bad.
If they are genuine Cat injectors then they are actually brand-new despite the fact that it may say "Reman" on the box. Also the Part Number on the injector would be 0R-xxxx or 10R-xxxx if it was Reman. The Part Number you mentioned in your post is a new Part Number not a Reman one. You'll note that I said "Cat gave up trying to remanufacture" HEUI injectors, not "gave up selling remanufactured injectors". A Cat dealer will still take your old injectors as cores against Reman injectors. However instead of the cores being shipped back to Cat's Reman facility for rebuilding they simply get junked. In the Parts Book for 4RC it gives the Part Number of 174-7529. However when I look at the Cat Parts system for price and availability of 174-7529 the information appears that it has been cancelled and replaced in the system by Part Number 174-7528 - that is the current Part Number for your engine even though your Parts Book may say 174-7529. Although they may look the same there will be major differences in fuel delivery and fuel injection timing between the 2 Part Numbers. I'm not saying that they will not work (the engine will definitely run, no doubt about that), simply that they are not the correct injector for your engine and may produce undesirable results when installed. Your idea of putting your existing nozzles on the new injectors may work, but again I have no information regarding what adverse results you might experience.
thanks for the answers. I have a CAT sis 2009. maybee that's why I cant find 174-7528. Buth allso i cant find it anywhere else on the net. I'm gona give it a try and see what hapendes. By my expirienca the bigest fault in dhese injectors are the internal ruber seals. If a bad oil is used in the engine afer some time the ruber stics to a intensifier piston, after that if an engine lays for a couple of days, it is inposible to start couse the actuation presure cant move the intensifier until the engine starts warming up. usualy my engine starts on 3 cylinders after a 3-5 mins of ether. than after 30-40 minutes it runs smooth and with no problems.
Three to five minutes of either? Can you get new seals and rebuild yourself? Sounds like you got it by the balls.
No serviceable parts in these injectors, at least not from Cat. Not sure about availability of aftermarket parts.
NOP. no way. couse as hard as I tried I couldn't find any parts for this typ of injectors. they are instaled in the engines for a ling tima as i can understand, it is overall not a good system. later generations are beter and wider spred. no one sels these seals and i was thinking to get mine custom built. buth there is stil a problem with the intensifier piston wich allso gets wared down. Now that you tel me that cat no longer ofers reman of these i think the reason is couse the barel is built in the main hosing and there fore cant bee replaced like the one on ford powerstroke and other cat heui engines. allso there is another problem , and i think it is the popet valve wich allso wares out so as the actuation presure increses the oil slips throo and stopes the intensifier from returning to zero position and refil the fuel. thi is manifested on the full throtle and ful load , the engine than runs as a gas engine with a bad distributor. I solved this by mechanicaly mooving the coil of the actuation presure valve on the heui pump for aprox 5mm from it's place. thos way the walve cant increse the actuation presure above 200bar. buth this allso decreses the max pover buth alowes you to work with thw machine quitq well. I hope you understand what I'm saying, this is how much kniwlige I could get from a year and a half of strugling with this engine. Anyways the Heui is a great idea buth in my opinion is that the engineers had to be stupit to think it will bee reliable. there is no so clean oil or fuel to keep these injectors functional for a long period of time. For industrial engines wee should hold on to clasical injection with Bosch pump. It is prooven and reliable and repairable.
it takes me two hours sometimes to start working with thw machine when I get to work
The HEUI system was a great idea on paper, and IMHO that's where it should have stayed ........... The Holy Grail of any hydraulic system is cleanliness, yet the designers of the HEUI expected their system to run on dirty engine oil. Yeah, right.
and the mooving ruber seal to preserve it's quality on 110 celsius of oil and fuel. when you put genuin ca oil in this engine after a good cleanup it starts perfectly for five days, buth that is all it can last.
Yair . . . skara2007 . You mentioned your spelling. It is creative (like your thinking with the engine) but completely readable and understandable. Maybe break your posts into paragraphs a little more like this one and (say) Nige's . When you are explaining a complex problem in English it helps to throw in a bit of white space. Back to Hydraulic Electric Unit Injectors. There is a lot of info on the system but just what is the design requirement/philosophy that requires such a complex system, that is to say a hydraulic system on top of a hydraulic system controlled by electronics. Anyone care to comment . . . and when these systems are working how big are the gains over a conventional system? Cheers.
I dont see any big gains. just more litle things to to get broken, wires to lose contact due to vibrations and dust, bad sensors etc. they talk about fuel economy and polution, and that is all right by me for the road, buth my engine is in the 60 ton demining machine with a demining tiler of 11 tons runind 250rpm-s in a dusty soil. doo you get the picture. I don't want to bee ower critical, this engine runs allmost perfectly once you get it to start and if you dont turnit of during the night thre wouldn't bee any problems, exept for about 150-200hp that are lost in the bad injectors. Buth it is a 1000hp engine so the 200hp is not too much if you slow down a litle bit. it is steel maby the most powerful demining machine in the world. When it warmes up, nothing stopes it exept deep mud.
Skara2007, my hats off to you, you are truly taking that bull by the horns. Good thinking on the actuation pressure adjustment. caterpillar oil seems to go alot longer in the 3400 and 3500 engines, any other brands seem to break down faster and get burned up. Would like to see some pictures of your machine.
hey guys I'm also dealing with the same issues. i have a peterson horizontal grinder with a 3412e, a morbark 1300 with a 3412e, and another 1300 with a mechanical 3412. nige is right about the reman injectors, cat no longer offers the "0R" part numbers anymore. cold starts are almost impossible. for some reason when the engine fires up and gets to 650 rpm, within 5 seconds the motor slowly loses rpms and stalls. won't even run on either. if i get the motor started and im able to get the rpms to 1000 before the 5 seconds, the motor will slowly lose rpms but regain momentum at about 450 rpms then will run steady. because of this i use almost 2 to 3 cans of either to get it running which makes me cringe every time i do it. last time i had cat there with the ET i had a speed sensor issue which i was able to take care of but the ET showed nothing about the stall 5 sec into start. so he couldn't give me an answer on what to look at. right now I'm thinking it might have something with cold mode and maybe the injectors that it runs on in cold mode are bad when in cold mode does it always run on the same 4 injectors? i did recently order aftermarket reman injectors and will change all 12, haven't changed all 12 in about 2 years. my mechanical 3412 can sit 3 months and start immediately in 0 degree weather thanks in advance i love this site and i appreciate all of your information on the site
I wil post some photos of my fat lady, buth for all rest of you regarding my first question to Nige . What do you think about my combining of injectors. Originals ar virtualy inposible to get unles directly from cat , buth the price is more than i can get in a year of working. The 174-7526 are quite afordable, so any sugestions are welcome. if I use the new injectors hydraulic part and combine them with the original noosles wich are steel in good condition. Do you think it wil work ok. My intention is if I manage to make this work to take wry good care of them by means of oil and fuel and filtration.
http://www.youtube.com/watch?v=Fo3mJXkOrFI here is the link to you tube video of the machine. it uses a 973 loader as a tractor and 3412 with hidraulics for the tool is in the trailer.
Nice unit, what I don't understand is that you don't make enough money in one year to buy 12 injectors? You have a special piece of equipment there, I would think you could charge a fair price?
JLsanzaro, I would love to see the actuation pressure on cold start, from ET and a manual gauge.
What I said is not rely that bad. the situation i Croatia deminingis that you get more money per sqare meter for mowing the lawn than for machine demining. The nex problem is that this machine needs big projects, you can emagine how hard it is to turn this thing around, I don't want to explain the rules of mooving the machine thro minefield. The project you get is cheep and small and you are lucky to get anything. and the transporting the machine is expencive , three tow trucks, or one truck three days transport. it takes two days to asemble the thing and vent the hydraulic sistem after asembly. Buth some time ago it wass posible to earn milions in one year.
The actuation presure is 99% the same on my engine.
In Croatia, if you bay 12 injectors directly from cat it costs aprox 30 000$
Now I understand, thank you
Yair . . . skara2007 . I believe I may have misunderstood your word "demining". An interesting machine. Most of us on here have not had to deal with the aftermath of war. Who do you actually work for, independent (say) farmers or local authorities such as boroughs or shires? Cheers.
it is a private Demining company. these are mostly small firms.
here is my fat lady.990hp trailer 3412E, 260hp Tractor loader 3126. 1000ccm hydraulic pumps, 7000ccm hydraulic motors on the tool.
After starting this thread back in October, I finally was able to get the injector part number. It's a 10R1265 and the engine serial number prefix is 4CR. Skara2007's starting problems are identical to this engine. Customer spent 3 hours getting it started on Friday so he could grind today, temperature was in the low 50*F. The north east wind started blowing yesterday, temperature is in the high 20*F and it started this morning. It's only after sitting for more than a week or so that it does not want to start.
my engine is allso 4CR, I just got the new injectors, they are not exact mach number buth like I said I wil try to combine them with the original noosles. I will post the results here. My problem is also turbines. Of about 12 turbines uset for these engines mine is the only one with the diferent cartridge. And ofcourse they cant bee found anywhere buth directly from cat, I don't want to tell you how much that will cost mee. This Engine is a bitch.
Can you tell mee something about injector trim codes on cat 3412E. I just got new injectors for the engine and I don't know where to find these codes. Is it nesesary to change these codes or what. thank's.
Only EUI injectors use Trim Codes, HEUI do not use them. The idea of the Trim Code is so that all injectors can be programmed to deliver exactly the same amount of fuel despite manufacturing tolerances. Some engines have the Trim Code marked on the solenoid, on others it's marked on the plunger on the top of the injector. The Code for each injector has to be manually programmed into the engine ECM for the specific cylinder where the injector is installed using Cat ET.
thanks Nige. that's a relife
What is involved in changing injectors in these engines? Any special tools or set up ect? I'm also looking for an engine manual for the 4CR serial number. Any info would be appreciated. Thank you.
You just replace them. there are some special tools that cat has, buth you don't need them. just pul them out carefuly. For the engine manual, it is best you download cat SIS, you wil hawe all the info there. When you replace the injectors you should clean the injector sleaves before inserting them back. Before You pull the old ones it would be best if you disasemble all the fuel lines from the cyl. head so that the fuel from the lines dont go in to the cylinders. Buth that is allso not a big problem for these engines.
Make sure after removing the old injector that the sleeve in the head is cleaned really well before installing the replacement. The sleeves (especially the little narrow diameter part right in the bottom) tend to carbon up and there is a chance that the tip can be broken off a new injector if you try to force it in to the hole. The Cat tools look a bit like the brushes used to clean out a baby's feeding bottle but they are wire instead of nylon bristles. We always used to do the final cleaning of the "hole" with fine grade abrasive paper on a wooden shaft to make sure the seals on the new injector had the best chance of surviving.
Thanks skara2007 and Nige for the info. What's the best way to get SIS?
Piratbay
Nige, the part number you listed, 174-7529 is for serial numbers 4CR1066 and up. The serial number of the engine I am working on is 4CR00705 and that calls for 138-8756 or 138-8754 or 138-8624. Which one would you use? Is there any reason why a newer serial number injector (174-7529) can't be put in the older motor? Thanks again, just want to get everything right before doing this job.
138-8754 & 138-8756 are basically the same thing, just one is assembled to a higher level than the other - it has the 115-3198 adapter block on top already installed. 138-8624 doesn't come up as a genuine number - certainly it's not an injector anyway (listed as a Bracket Assy). Your engine was originally built with 138-8754 injectors. However if you ask for 138-8754 today the system will actually send you to 174-7526 (apologies, I posted the wrong number before). 174-7526 & 174-7529 are effectively the latest replacement numbers for 138-8754 & 138-8756 respectively. 174-7526 is listed in the system as a "Field Replacement" for all earlier Part Numbers of injector.
hi Nige through them in the bin reman is not worth the hart ache must bin 50 a week