Hydraulically-actuated, Electronically-controlled Unit Injector

[hammersley]

Does the PSD use this system. Can someone explain how the oil pressure is used to activate the injectors on the PSD and why would one want to do this?

 

[BigYellowIron]

I can explain a basic overview. we have a cd rom that explains the cat system in great detail but i cannot figure out how to copy the pictures onto here.



they use the engine oil to actuate the injectors. The engine has a piston type pump that produces high pressure oil (3000-5000psi). This is sent to the injectors through a port in the head. the jujector has a solonoid that controls a popet valve. this valve allows the HP oil to flow into the injector. The inj has a piston that is attached to a plunger. simalar type as plunger and barell as on the p7100 onlu it is contained in the injector. The HP oil flows on top of the piston and forces it down and pressurizes the fuel inside the barrel. the oil basicly does the same thing that the cam does in the p7100 ( i keep refering to the p7100 because i think that many are familiar with its operation) The quanty of fuel that is injected id determined by the duration of the popet valve being held open. The injection timming is determined by the ecm. I don't know if i have missed anything on this quick overview. I will try to find some pictures of a cut-away of the HEUI injection system ans see if i can copy them on there. Let me know what is unclear and i can define in more detail. I have access to almost any info on the cat HEUI which is pretty well the same a s the PSD.

Just let me know where i need to expand, I have no idea of your knowledge leve on this subject

Adam

 

[Dr.Evil]

It's what the PSD and some Big CAT diesels use. Engine oil is controlled by an elec. solenoid same way as a gas engine injector controls the gas, And the oil runs into a larger chamber with a smaller plunger that increases the fuel injection pressure to about 7 times the oil pressure. That's why PSD's can hit 20,000 PSI inj. pressure into the combustion chamber. Actually it's HEUI, H-ydraulic E-lectroning U-nit I-njection. Actually with over 1. 5 Million PSD's on the road the system has proven really reliable.

DENNY... ... ... ... ... .....

 

[Grey Wolf]

HEUI a Caterpillar product, you can check here to get an idea of the product!



http://www.caterpillar.com/products...s/07_heui_fuel_systems/heui_fuel_systems.html

 

[Evan A. Beck]

BigYellow,



Good description on the HEUI... The HP oil fogures you have are a bit high, usually varies between 500-3000 psi.

 

[hammersley]

The explaiantion was great - this obviously explains the tremendous difference in the cost of the injectors between the cummins and the PSD. - However from a practical standpoint-if you're trying to make something less complicated - doesn't the ISB accomplish the same without the potential maintenance and cost associated with the HEUI?

 

[Amianthus]

I've heard it put this way by someone here about the different types of injection systems.



Cummins - Smart Pump, Dumb Injectors (Simple Injectors)

Duramax- Dumb Pump, Smart Injectors (More Complicated Injectors)

Powerstroke - Dumb Pump, Dumb Injectors, Smart Oil Solenoid for Injectors (Way Complicated Injectors)



At least that's the way I look at it in my simple world.

 

[Bad340fish]

Didn't like it

I used to drive a 97 superduty at work with a PSD in it. The truck had the crap worked out of it, about 15K most of the time all of it on the truck no trailer. After it got to around 120K it would start getting check engine lights and running like CRAP. Fords fix was to just change the oil at every 2500 miles. And then like clockwork the light would come and and it would go off as soon as you changed the oil. Idle quality was alot worse on 2K+ oil also. Now I drive an INT truck with a DT466E and am starting to see the same problems at 97K.



Here is my overview

PSD=High Dollar Injectors, No injection pump, just a mechanical fuel pump similiar to one on a gasser. Used just for getting the fuel to the injectors.

Cummins=Cheap Injectors, Injection pump either electronic, or mechanical. Either way they are not cheap to replace.



I change my oil religously(Sp?) but even if I didn't I would not want oil quality to effect the performance of my vehicle. JMO

 

[J DeMaio]

I'll tell you, I saw one of these injectors and they feel like they weigh about 5 pounds. They are entirely too big! Also, this is a very high dollar system and they sometimes have trouble with them don't they? Also, instead of the turbo being oiled by the engine oil you have to get it to the injectors, which means the cleaner the oil the better. This translates into higher maintenance cost as well as more routine oil changes like 2500 miles vs. 5000 miles. Boys, we know who makes the real engines and thats why we have what we have, the CUMMINS. Also, Bosch makes great fuel systems and they're on the Cummins, Duramax, and whats on the Powerstroke, do they really not have injection pumps?

 

[COBRAJET]

The PSD's do not have injection pumps... they have expensive injectors instead of expensive electronically controlled pumps. There are very few reported problems with injectors. I read about way more injection pumps going bad than I do about bad injectors on a PSD. I can't recall anyone having a problem with an injector. Number eight has been replaced for cackle trucks, but this is not an injector issue. They are expensive around 2K for a set, because they are made with titanium and are a split shot injector. A complete fueling system for a PSD is cheaper than a Cummins. Everyone over here is so use to buying new "BOMBED" injectors for so little money... myself included, that the sound of 2K is crazy. Spending a couple grand for an injection pump sounds kind of crazy to a PSD owner who only has a common electric fuel pump mounted on the frame rail. The injectors are coming down on the PSD's as the aftermarket guys get rolling. Oil is cheap and most guys are changing around 3K anyway. I change the Cummins at 3K just like the PSD. Several companies will now modify the owners stock injectors for about 1200. 00 now. It was 3K ago. The advantage goes to Cummins in the injector battle, but 130HP chips can be had for less than $300. 00 for a PSD... . BOMB ON!!... CJ

 

[Bad340fish]

COBRAJET, this is kind of off subject but does the DT466E have glow plugs or a grid heather either one?? I have left my work truck sitting outside in below freezing temps for days without bieng plugged in. Fired right up monday morning like it was 60* outside. I was even able to drive off like it was warmed up. Whats wierd is our newer trucks with automatics in them have to warm up before they will even move. Just curious thanks

Clark

 

[yogibear]

If I changed oil every 3K mi. , I would be changing it every week. I changed mine the 1st time at 3K, to synthetic, the last time was at 75K, filter every 10 to 12K, with sample at that time. Have 118K now and everything is fine.

Larry

 

[Power Wagon]

The concept for the hydraulicaly actuated, electronically controlled injector is great. It has the capacity to overcome some of the inherent weaknesses of mechanical injection in an environment where a wide range of speeds is used.



It allows any RATE of injection as well as any QUANTITY of injection completely independent of each other. Mechanical pumps, including the P7100, VE and VP44 all generate rates of injection based upon engine speed and compressibility of fuel/line size/ opening pressure / flow characteristics of the system, including injectors. This is why idle is often subject to smoke on the big older cummins. The low speed of injection simply didn't result in good atomization of the fuel. The B engine sort of has the same problem when you start putting in big nozzles for high horsepower. The rates are too low at low speed, resulting in some undesireable stuff.



The HEUI system is ok, for most intents and purposes. It's a bit expensive to work on, inconvenient as heck when in a Ford truck, but theoretically, should outperform any of the fuel systems on the B engine. Doesn't seem to be the case, as PSD fuel economy isn't particularly impressive.

 

[BigYellowIron]

Originally posted by J DeMaio

I'll tell you, I saw one of these injectors and they feel like they weigh about 5 pounds. They are entirely too big! Also, this is a very high dollar system and they sometimes have trouble with them don't they? Also, instead of the turbo being oiled by the engine oil you have to get it to the injectors, which means the cleaner the oil the better. This translates into higher maintenance cost as well as more routine oil changes like 2500 miles vs. 5000 miles. Boys, we know who makes the real engines and thats why we have what we have, the CUMMINS. Also, Bosch makes great fuel systems and they're on the Cummins, Duramax, and whats on the Powerstroke, do they really not have injection pumps?

Don't forget about the high dollar piston oil pump that supplies high pressues oil to the injectors.

adam

 

[Evan A. Beck]

Even the little parts in the HEUI system are exorbidantly expensive... I replaced an Injection Pressure Regulator (IPR) lat week, and the little bugger was $250!!! It's just a solenoid to control pressure, that's all... Riduculous...



Also, the HEUI injectors have over 50 moving parts in each one. I have seen them disassembled, and it is mind boggling what is in each one. I have also seen the disassembled injectors out of a B. Just a few parts, nothing complicated at all.

 

[Dr.Evil]

I think Seimens makes the HEUI Injectors don't they? How many parts are in an injection pump? Last one I saw the insides of was a ROOSA-MASTER. It had A LOT of small parts in IT!

DENNY... ... ... ... ... ... ... .....