2001 DT466E

[robp823]

I have an DT466E model in a 4300 that my friend has been having issues with.Says the CEL comes on then it bogs down.Then all of a sudden the light goes out and it comes back to life.Everytime i hook up to it it has a 333 logged icp above or below desired.Ive driven it with my laptop hooked up watching ICP,IPR but i have never been able to get it to act up.Ive been through the whole harness,ohmed out ICP and IPR circuits,shook down the harness even load tested circuits with a headlamp and found no problems.I did replace the icp sensor because there was oil coming through the connector.The next day they used it he said it did the same thing again.I just finished installing a test ipr.Anybody ever run into this with an E model?I wish i could get it to act up to at least see what the ipricp is doing when it happens.

[Bruce Amacker]

Several common things baffle guys with 333 codes on DTs. The first is lack of low pressure oil feeding the HPOP, the second is the HPOP itself. Verify good oil pressure, and to test the HPOP momentarily ground the IPR return wire to see if the HPOP will put out the 4100psi it's rated for. I've seen plenty of them that will run fine, set 333s, and only put out 1800-2000 when deadheaded. Intermittent ICPs, IPRS and the connector to the IPR are also possible.

 

The IPR connector is commonly damaged during engine service and loses its continuity, which will immediately kill the engine and frequently NOT set a circuit code. Wiggle the connector while watching voltage on the return wire at the ECM, it should remain steady in the 10.5v area at KOEO and 12.0 at idle. Substituting a known good IPR is really the only way to verify it's good. The o-rings tear on the IPR commonly, too, I usually change the whole IPR if the o-rings are torn.

 

Good Luck!

 

[Mbl35]

I've seen this happen on econolines with 7.3. It happens intermitantly.

When it looses power the check eng. lt. Comes on especially on upgrades.

Then it will pick up power and the lt. is off and has a p1212.

Every time I had one with this symptom I changed the high pressure

pump and it fixed it. While in there inspect all connectors, ipr o-rings and

icp for oil leaking through it.

[blown99]

Get the engine oil hot and perform a dead head test. This will require a gauge that can go to 5,000 psi and a #6 JIC male fitting the thread into the high pressure oil hose. Use your break out T and apply battery power and ground to the ipr valve and crank the engine. The gauge should read 4100psi. If it does not then swap in a test IPR valve and retest. The ipr valve is the same is a 7.3l. It is usually a safe bet that the hpop has failed if you do not have a good ipr to test with. A 333 code will be set when the ipr duty cycle exceeds around 50% for more than a few seconds. The icp is not matching the desired. Once the hpop starts to fail, become weak, it can not produce enough pressure to satisfy the icp desired and the 333 dtc will be set. A failing IPR valve will usually leave you with a intermittent stalling condition with no codes or a crank no start.

[robp823]

Thanks guys.O rings were ok on ipr.Put test Ipr in.Waiting to hear back.Will dead head pump if that doesnt fix it.

[robp823]

saga continues.Was driving the truck last night and cel came on.code 333.So its not the IPR.Going to get it hot and dead head pump tonight.Is it possible for injector o-rings to cause this issue bleeding off pressure?"

[Bruce Amacker]

Unlikely, my money is on a bad pump. Why didn't you deadhead the pump? It's quicker than changing the IPR-I do it at idle by grounding the IPR return and watching pressure. I'm assuming you have SM or a good scan tool. If you don't, you could watch ICPV with a DVOM while backprobing the IPR and grounding the return wire. (It should be .2V KOEO and I'm thinking 4.5+ VDC grounded) IH also makes breakout harnesses for this (I could get the PNs if you really wanted, but they should be on the SPX site) but the IPR is very easy to access on this engine. Pull the IPR plug off- KOEO, one wire is hot, that's the power supply, you want to identify and ground the OTHER wire, which is the ECM PW modulated ground side. (sidebar- beware the EGED diag sheet has a misprint on this circuit and the wrong voltage is shown in the chart)

 

You could also test drive the truck and watch IPR% and ICP which would tell the tale. My guess is that at WOT IPR is going to 70-85% and ICP is staying around 2k, which is what I usually see. Mark might chime in here as I'm sure he's seen more of these than me.

 

If the injector O-rings leak it's a different complaint- if the center O-ring leaks, it pumps the contents of the oil pan into the fuel tank. If the top O-ring leaks, it's usually a hard start cold (extended cranking) along with an elevated IPR command, because the oil bleeds out of the HP oil rail while it's parked. If you have a lot of experience with 7.3 PSD's, there's a lot of similarities in the systems.

 

 

Good Luck!

 

[robp823]

Ok......So lets recap.Ive tried an IPR.Tried a test ICP sensor.Checked over connectors to IPR ,ICP and ECM.Ohmed and load test circuits for those.Shooked down harness.Now i just got finished dead heading the pump with an actual gauge,cranking after getting it hot,the pump makes almost 5,000 psi.Thats without energizing the IPR.I agree with you Bruce on it being unlikley bad injector orings.Could the pump just be acting up intermitenly????I dont have have a test Pump.Pumps are expensive.So when i tell this customer it needs a pump i want to be right.Unfortunatly the only time ive ever gotten it to throw the code and cel i did not have my laptop hooked up.I do have DLC2.

[Bruce Amacker]

Something is seriously wrong here- it should not make 5K without the IPR energized, it should be somewhere between 0psi and 200psi. The IPR is a dump valve which is normally open. If it is not energized, it sends 100% of the oil the HP pump makes back into the sump via the front cover, not making any ICP. Later engines make 200-300psi with an open IPR but I can't remember what a E engine makes. If you are truly making 5K with an open IPR, your edge filter is plugged with crap in the HPOP and easily cleaned. I've seen this before caused by sloppy workmanship doing stuff inside the engine and leaving silicone and debris which gets into the pump and blocks the passageway going to the front cover. If this is true your IPR will be under 5% idling because the ECM will not call for more HPOP. You should be able to unplug your IPR idling and the engine should immediately stall. If your ICP is really high, the engine will sound super aggressive, noisy, and pissed off because the timing will be cranked up really high by the ICP pressure. The noise will make it stand right out. If it idles fine, I doubt your ICP is that high (maybe your gauge is fucked?).

 

 

If the HPOP makes 5Kpsi it's probably not the pump, I can't ever remember seeing a pump that was intermittent. If your ICP is low look harder at the LPOP pressure, that kicks a lot of guys asses. They struggle with the system, not realizing the whole HP system depends on the LP system supplying enough oil. Go for a RT with SM hooked up, and the following pids pulled- ICP, ICPV, ICP desired, IPR, and oil pressure. Do a recording of a bunch of WOT blasts like 1/4 mile drag races. You should expect IPR to be high during this time, but (IIRC!) not over 70-80%. IIRC if it hits 85% for a few seconds and ICP/ICP desired spread considerably it will set your 333.

 

IIRC IPR% should be 9-11% at a hot idle but will go up drastically with load. You should see 550-600ish at idle and 2700+PSI at WOT under load depending on HP rating and other things. I like to look at ICPV and not ICP, that translates to .20v KOEO, 1.5v cranking, and about 1.0v idling hot. ICPV is an input into the computer which is more accurate than ICP, which is an output calculated by the computer. If the ECM is pissed off because the clean power is dirty, the alt makes too much AC, or a number of other things, it might make bad decisions and lie to you about ICP. You're young, learn to use ICPV over ICP, it will save your ass a few times during your career. I'm in town tomorrow if you want to call.

 

[robp823]

Bruce im sorry the IPR was energized when i did the dead head test.Was going from 6 in the morning till late last night .PM me your number and i will call you tommarow.Thank you

[Bruce Amacker]

It's in my profile, 440-846-3885.

 

[blown99]

A hpop can be intermittent. Many times, they pressure test fine with cold oil then once at operating temp, they begin having issues. They also can be intermittent when hot. In these situations I bring my gauge with me on the road test and as soon as the 333 goes active, I pull over and dead head the pump. You can do this by yourself, bring a jumper wire, pop the cover off the power distribution box, with the key on, unplugg the starter relay and jump the pins, watch your gauge, there is no need to full field the IPR, the ecm will give it its max duty cycle and with the limited volume of oil needed to actuate a pressure gauge you will be able to get an accurate reading - 5,000psi. Injector o-rings will give you crank no start conditions, typically not a 333 code. You can though, have injectors bleeding off oil out of their return port this is much more common on injectors with more than 5,000hrs. To check this, remove the valve cover, remove the plastic oil deflector shields, unplugg the cam sensor, energize the IPR, crank the engine, look for an injector that is dumping more oil than the others. The valve cover is very easy to remove on a 4300, you do not need to gut the cab to remove it. I have also seen an EOP sensor shorting v-ref to ground, this was causing an inaccurate icp voltage causing a 333. You could unplug your other 5v sensors and run the engine to see if you could duplicate the complaint. Your IPR % should not go over 45% under full load. Anything much more than that indicates a system leak/problem. SM makes this hard to view with their auto scaling, MD you could see the two graphs (ICP and IPR%) separating from each other with just a glance of the screen. Also, Do not forget what the code description is. ICP above or below spec. Usually the problem is low ICP but there are times when the ICP is above spec. ICP above spec will occur when there is a low voltage condition and not necessarily with the ICP/IPR. Use SM or MD and monitor battery voltage, be sure it is the same as vbat. Old well used ECM relays that have some arching on the contacts will cause low voltage to the ecm, somebody that change a set of batteries and missed one of the jumper cables so the battery that the ecm clean power wires are hooked to is not charging or receiving a low charge from the alternator, loose starter cables/battery cables as well.

Also when dead heading the pump, do not be afraid to crank the engine for 20-30 secs continuous. Sometimes it takes some sustained pressure for it to show its weak under load.

[robp823]

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[robp823]

Finally got this thing to act up and got a recording.Bruce i tried getting ICP volts but using Diamond logic controller 2 it just kept saying NA.This is wide open pulling a hill.At around 31 seconds is where it throws the fault code 333 and goes to derate and the ECM goes off its calculated values.Before that you can see how much lower ICP is than ICP desired.The IPR is pretty much at 65% the whole time.Thoughts?

[blown99]

You don't want to be using DLCII for a DLC system. When you open up MD, scroll down and click on DLC. Most things will work in DLCII but the ecm's are two different animals. Your IPR duty cycle should not go over 45% on a good system. 65% indicates a condition that the ecm can not compensate for whether it be a worn hpop, leaky injector, sticking ipr valve. You need to dead head that pump when the fault code is setting. Keep an eye on the oil temp as well. make sure when you are road testing trying to duplicate the condition, that you oil temp is 185 or hotter.

[robp823]

I have a known good IPR valve in it when the problem is occuring.Problem usually only occurs when EOT is up over 185 degrees.Is it possible for an injector to bleed off that much ICP???

[blown99]

Yes, it is possible for an injector to bleed off enough to cause the 333 code. Not to common though. To check, get the breather tube assemble into the valve cover worked free, run the engine in the shop, get the oil temp up to 185 or hotter. Shut off the engine, remove the valve cover as quick as possible - remove the ac compressor and the cover slips right out. Unplug all the injectors, install your breakout t into the IPR valve and full field the ipr. Have somebody crank the engine and look for oil coming out of the injector return port. One of them will have an excess amount of oil compared to the others that will be coming out of this port. If they are all equal, then move on. With the valve cover off and the ipr energized, with someone cranking the engine, look for oil leaks around the injector body indicating a failed upper o-ring.

[robp823]

Sorry it took me so long to update this.I finally pulled the valve cover off while the engine was hot.Ran engine.Cylinder 2 top injector oring was completly blown out.Never seen that before.Lesson learned.I appreciate all the help guys .Thank you.