"engine load 66%" while uphill full throttle?! t444e

[wanderingturtl]

ServiceMaxx says engine load 66% while going 45mph trying to accelerate, full throttle, slight uphill. Shouldn't it be 100% engine load or close? it also was not accelerating and felt low powered. I verified that the accelerator pedal position sensor is good; it goes to 102% throttle.


Previously it had given a code like "engine power reduced to match cooling system efficiency *M*", but I cleared that code and it didn't come back. Would it still be running in reduced power mode even though it wasn't showing that code?

[magnakansas]

Boost pressure, fuel?, fuel pressure, injector on time or pulse width, exhaust temperature, .... with 100% throttle, you should have, 100% fuel- provided everything the fuel computer thinks it needs is there and there are problems..... 66%. Sounds like you are missing boost. And because of that the computer will not add needed fuel. THIS IS A GUESS!

More information is needed. This maybe a good time to pay mechanic that is knowledgeable. The knowledge he has earned is what you are paying for.

William

[cadillackid]

what did the servicemaxx say your oil temp and Coolant temp were. (not the dash gauge).. the ECM will de-rate on oil or coolant temp.. a bad sensor can send the reading to the ECM way high..

[Bert06840]

Originally Posted by cadillackid

what did the servicemaxx say your oil temp and Coolant temp were. (not the dash gauge).. the ECM will de-rate on oil or coolant temp.. a bad sensor can send the reading to the ECM way high..

Makes me think… most coolant sensors are NTCs, which have a very non linear characteristic…




So the ECM must compensate for that lack of linearity in an algorithm. If there’s water ingress into the sensor, or if the wiring is exposed or oxidized or otherwise messing with the curve, it could not only report an incorrect value, but the curve shape would be off, or the curve could be shifted. In such case, the ECM could see it as the engine heating up too much given the amount of energy that is being put into the system.

If I had to bet, that sounds like a good candidate.

If you can read codes, you can probably also read live data. What is the coolant temp reported, when cold and when hot? You should see pretty accurate numbers.

[Simplicity]

Okay, my ignorance is showing here.

How did you read what the ServiceMax was reading for engine load?

I've got a bluefire and it won't show my engine load. If it's available in the ECM, I'd think the bluefire would pick it up??

This may be overly simplistic, but how old is your fuel and fluids?

When I first had my bus, it would occasionally give a sputter. The more I drove it, the less it did it. Then, when I put in new fuel and added some PS additive, it really cleared things up more.

It's a cheap and easy thing to try. If it helps, it may also give a better indication of what is the issue.

The oil cleanliness could be an issue considering the HPOP system.

[cadillackid]

Maybe you have to turn on that PID? I thought I’ve seen engine load in my bluefire .. my digital dash device shows it.

Bert - that’s often how coolant temp sensors fail they are just off. They are thermistors and like any electronics are subject to drying out or cracking or contamination .. I’d have to look but I was thinking the service manual said for her code that it’s an oil temp thing .. my service manual would tell me ..

[wanderingturtl]

Originally Posted by magnakansas

Sounds like you are missing boost. And because of that the computer will not add needed fuel. THIS IS A GUESS!
William

I was wondering if the turbo is working right. It's not whistling as loud as I think it should. Is there a boost pressure sensor? Does the ECM control boost pressure?

[wanderingturtl]

Originally Posted by cadillackid

what did the servicemaxx say your oil temp and Coolant temp were.

When my laptop died coolant was 210F and oil was 202F. I'll go on another run tomorrow morning and monitor it.

[wanderingturtl]

Originally Posted by Simplicity

How did you read what the ServiceMax was reading for engine load?

I just click Session and then Performance and it's one of the parameters listed.



I just went to look again and possibly answered one of my own questions - boost pressure is listed. I'll be monitoring that in the morning too.

[wanderingturtl]

Ok, so I learned that boost pressure is monitored by the MAP sensor.
I replaced the MAP sensor and now it reads boost pressure. But the highest the engine load got up to was 91% under full throttle, and it only had 1.1 psi boost or thereabout.


I think that maybe old fuel could be a contributor. The engine is pinging or a mild knock and I *hope* that's because of old fuel. The exhaust smells bad and I know for sure the diesel in the tank is at least a year old.


But I'm also wondering if the fact that it only go to 91% engine load is that it's set at 195 hp and these engines can be set up to 230 hp. Or is something wrong with my turbo?


My next step is to run out the old fuel and fill up with fresh diesel. I've heard that can make a world of difference.

[magnakansas]

I am unaware of any turbo diesel that runs less than 8 psi of boost. Most diesels run around 15 to 30 psi. I don’t think your year old diesel fuel is the culprit. I would assume engine control system is adding all the fuel it can with low boost. I would add a 0 to 60 psi mechanical gage and drive again to verify intake manifold pressure.

William

[cadillackid]

I cant remember what wqe went thriough and didnt on here but low boost.. check that your EBPV isnt stuck closed that will kill your boost and power (you could be lucky and not have EBPV but most did..



if you blew a hole in a turbo boot osmeplace that will cause low boost.. I know on the later navistar stuff if your boost is too low it will defuel not sure on these if they do.



my 190 HP 444E was making 14-16 PSI of boost stock at about 2300-2400 RPM (it makes about 28 now tuned)..


the fuel pressure at the fuel pressure test port under the hood on the regulator should be 45-72, the higher numbers come from the later models (01+) or if the Fuel pressure spring kit was installed.. otherwise closer to 45.. and the needle on your test gauge will bounce because your pump is mechanical.. thats normal.



Gallons per hour of fuel used is another parameter to look at. .if the engine thinks its fueling up heavy your GPH will jump up from the 0.5 it typically is at idle. GPH isnt measured there is no transducer it is perceived based on pulse width and fuel PSI (constant).. I suspect with the load factor low that its defueling for some reason.


im also assuming you didnt accidentally set a speed or RPM limiter in servicemaxx



the HPOP IPR duty cycle should run at least 50%, I think it maxxes at 65% on 190 units. the pressure will be north of 2000.. you will set a code usually if HPOP is an issue.. I was setting code 333 on mine when the HPOP was weak.