Help With Engine Load

[Caleb Hardy]

I have been trying to chase down what would be causing my high egts. At first I bought into my turbo was not the right size, the tuning on quadzilla could off, and bit the bullet after all that and got rpms in the range they “should be” with no luck still. So I watched a video of MM and noticed the engine load was 17-19% while driving 65mph. My engine load at idle in neutral or park is 20-22%. In drive not moving 26%. Driving at 65mph on flat ground little to no wind 25-30% engine load=warmer egt’s. Now if I’m going slightly down hill and my engine load is 23% or lower my egts mimic the egts in the video I watched. I have a few questions. What are some possible causes of high engine? What kind of engine load are others seeing at idle and cruising? (Automatics) How does your engine load reflect your egts? Thank you ahead of time for all your input.

[Me78569]

what injectors do you have and how old are they?

 

[Caleb Hardy]

Newer injectors 40k miles on them or so. They are 7x0.010 VCO set to 320 BAR. Engine load readings have stayed the same since those were put in. Engine load prior those injectors is unknown never looked at engine load at the time.

[Me78569]

what brand injector?

[Caleb Hardy]

They are back to DAP.

[Caleb Hardy]

Just my luck……crickets…….hahahaha!!! I usually abnormal mechanical problems. If I’m able to track down the problem I’ll be sure to share. God bless.

[LorenS]

On 8/15/2022 at 10:17 AM, Caleb Hardy said:

They are back to DAP

This sounds like you pulled the injectors and them them back to have them tested.

 

My engine load in park is 6-8%,  it fluctuates a little. Cruising on highway, my engine load is higher than yours, but your injector flow rate is higher so duration is lower for same amount of fuel.

[Caleb Hardy]

So given your higher engine load percentages at cruising speed your EGT’s I’m assuming are still low (500-650). If it is I’m going down a rabbit hole that leads to nowhere. I even went overboard with cruise timing 23* with oil temp varying between 150-165 degrees. I guess the “high engine load” I think I have is not the cause of the elevated EGT’s. Forgot to mention I don’t think it matters after reading about EGT’s towing I have around 2000lbs-2400lbs in the bed of the truck. (Welding equipment) but it might.

Edited September 27, 2022 by JAG1

[LorenS]

I've tried all I know to do with my tuning, and 650⁰ is just pretty normal for my truck even flat ground, both Adrenaline and my ISSPRO. Slight hill and it's pushing 800. My injectors are remans, ballpark 50k miles.

 

I'm no expert on this stuff, but it sounds like your injection pump is fighting like hell to put fuel in the cylinder. Do you have a fuel pressure gauge? Filter(s) clean? Sock in fuel tank crudded over?

[Caleb Hardy]

Fuel pressure is 15-18psi. Fuel filters (CAT 175-2949 CAT 1R-0750) are changed every 5k during truck service. Lift pump is a fuel boss (mechanical). The fuel tank sending unit was recently removed and cleaned when I replaced the stock 35 gallon tank with a 60 gallon. I have thought about putting the stock injectors in just to see if it is the injectors causing the issue but it is quite a bit of work just to see. Same with idea of pulling out the transmission. (Working out of town, home 1.5 days week, little family time hahaha) I just know I threw a lot of money at this truck trying to get my EGT’s in the ballpark to what other guys are reporting. The one I thought would be the cure all turned out to be the biggest costly mistake with no gain, re gearing. But you live and learn. Makes me wonder about engine load percentages and how the ecm calculates it. Do you have bigger than stock tires? Thanks for chiming in!

[LorenS]

4 minutes ago, Caleb Hardy said:

Do you have bigger than stock tires?

No, but I have 3rd gen 17" wheels so currently running 265/65-17 at ~30.5" diameter, similar to 245/75-16. They may weigh more, but doesn't mean much at a constant rotational speed.

 

I haven't a clue how the ECM actually calculates % engine load or what it uses for assumptions. Being 90s technology I'd say it has no way of figuring out on its own if injectors are changed.

 

Perhaps it just determines what percentage of the total available injection duration is being utilized and reports that. I just don't know.

[Caleb Hardy]

I’m wondering with higher pop pressure I can afford to go even more with light throttle timing as long as the oil temp stays where it should. The transmission locks the TC in 2nd gear and stays locked through 6th. And haven’t had any bucking issues. I’ll try adding a little at a time and see what happens. Thank you!

[Mopar1973Man]

Watch the timing close and then listen if the rattle gets too loud you might be getting negative torque. About 21 to 22 degrees at 2k RPMs is about as fair as you can reach. But this is based on the cetane of the fuel. Lower cetane can take the extra timing. If your using any cetane booster you have to retard because the inherit advancement that cetane boosters give. Be aware that higher cetane has lower BTU's. Lower cetane is best being it has the most energy.  

 

As for engine load if your going the right way the engine load will get lower. If its rising then you going the wrong way in timing. 

Edited August 18, 2022 by Mopar1973Man

[Caleb Hardy]

What I’m not understanding is that the engine load doesn’t change when cruising when timing is adjusted. Even if I run the quad at 0 engine load is the same (25-30). No cetane boosters. In warmer weather is cetane higher or lower? Could it be something in the injection pump? Thinking it’s calibrated one way but it’s actually the other way? If that even makes sense.

[Threadzy]

What does your tune look like? 

[Caleb Hardy]

It’s on my I pad that does not have a service plan on it. Once I get to the hotel I will post them. Or if one of the guys at work can figure something out I’ll do it sooner.

Got it figured out! Hahaha

iQuad-tune.json

[Me78569]

Issue is not in the tune.  Your load is high at idle so it must be something in the pump or injectors causing you to need a lot more duration than normal to run.

[Caleb Hardy]

Anyway of adjusting duration with the quadzilla? Or just pull the pump and injectors and have them test everything?

[Mopar1973Man]

Nope. Below 1200 RPMs the ECM is in control. Quadzilla is only monitoring the CANBus, till RPMs rise.

[Caleb Hardy]

Dang…..I guess I’ll pull the pump and injectors to have them tested.