TDStuart Tuning Adventure

[engineermike]

Does pcmtec use a speed density calculator or no?

No, and the hpt one probably wouldn’t be much help in this situation.

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[markmurfie]

I think that's what @markmurfie was pointing too.

From my research, the manifold volume might influence the speed density calculations so I want to try updating that.

I think what I was getting at was if your stock throttle body and model is not agreeing with your stock MAF sensor and housing about how much Air is getting into the cylinder. You might be chasing your tail with the SD tuning.

Still think it's something with your throttle body.

 

[engineermike]

@tdstuart Is the tb really dirty?

 

[tdstuart]

I think what I was getting at was if your stock throttle body and model is not agreeing with your stock MAF sensor and housing about how much Air is getting into the cylinder. You might be chasing your tail with the SD tuning.

Still think it's something with your throttle body.

You can't mention needing new parts pretty soon @GregO will demand I replace the entire car for new parts

Shouldn't we be able to compare voltages from my logs to someone else with a 15-17 throttle body? The car can only see the voltage so if it was truly the throttle body we should see some weird voltage things. From what I see the car seems to be reporting that the throttle body is perfectly fine

 

[tdstuart]

@tdstuart Is the tb really dirty?

No, I cleaned it not that long ago. From the logs you would think the car is perfectly happy with the tb

 

[engineermike]

@tdstuart I’ve tried manifold volume numbers down to 0 and up to huge numbers and never saw a load or SD issue. However, throttle response was drastically affected.

 

[tdstuart]

@tdstuart I’ve tried manifold volume numbers down to 0 and up to huge numbers and never saw a load or SD issue. However, throttle response was drastically affected.

Okay Ill give it a shot anyway. Its my only thought since I know nothing about the SD stuff

 

[engineermike]

Shouldn't we be able to compare voltages from my logs to someone else with a 15-17 throttle body? The car can only see the voltage so if it was truly the throttle body we should see some weird voltage things. From what I see the car seems to be reporting that the throttle body is perfectly fine

The throttle angle is on a PID feedback loop and very sensitive to errors. It will throw a code very very quickly if it isn’t where the pcm thinks it should be.

 

[tdstuart]

@ 133,000 miles who would argue that.
Also is there any merit in a new DBW accelerator pedal, that’s a lot of cycles at this mileage ?

Too bad I can't just throw an 18+ tb in. I think my friend has one laying around.

I guess I could try borrowing my friends tb off his gt and test.

 

[markmurfie]

You can't mention needing new parts pretty soon @GregO will demand I replace the entire car for new parts

Shouldn't we be able to compare voltages from my logs to someone else with a 15-17 throttle body? The car can only see the voltage so if it was truly the throttle body we should see some weird voltage things. From what I see the car seems to be reporting that the throttle body is perfectly fine

Install a manifold pressure sensor, and lets tune your SD.

Not sure it will fix it, but maybe.

 

[tdstuart]

Install a manifold pressure sensor, and lets tune your SD.

Not sure it will fix it, but maybe.

How hard and expensive is that? Can you wire it up directly to the pcm or am I going to need some standalone thing?

 

[tdstuart]

Manifold Volume did not fix it

 

[GregO]

You can't mention needing new parts pretty soon @GregO will demand I replace the entire car for new parts

Shouldn't we be able to compare voltages from my logs to someone else with a 15-17 throttle body? The car can only see the voltage so if it was truly the throttle body we should see some weird voltage things. From what I see the car seems to be reporting that the throttle body is perfectly fine

Maybe consider a thread title change to;
TDStuart Detuning and Misadventure

 

[tdstuart]

Maybe consider a thread title change to;
TDStuart Detuning and Misadventure

The logs don't indicate to me that anything is weird with the throttle body. Voltages hold steady, and the car thinks its fully open.

My point is that how much more do you want me to replace? First it was the maf, then the cai, then the injectors.

My car has a weird paddle shifting issue when you shift from 3-4 at high rpm. Is your first guess that its a transmission issue because the car has 133k miles? It's a tune issue because I had Lund specifically tune it out and it was a weird thing that was appearing in my stock tune file.

Its not that I don't appreciate your insight or opinions but I would like to see a little more proof that my tb is the issue before I spend money on a new one. I'll see if my friend has time this weekend to let me swap ours.

 

[WildHorse]

IF MAF and LOAD aren't agreeing:

1. MAF sensor malfunction: The MAF sensor may not be accurately measuring the amount of air entering the engine, causing a discrepancy between the MAF and Load readings. This can also be it's positioning in the tube.

2. Intake leaks: A vacuum leak or unmetered air entering the intake system after the MAF sensor can lead to discrepancies between the MAF and Load readings. At higher throttle positions, these leaks can become more apparent as more air is drawn into the engine.

3. Airflow restrictions: A clogged air filter or other restrictions in the intake system can disrupt the airflow, causing discrepancies between the MAF and Load readings.

4. Tuning issues: In some cases, discrepancies between MAF and Load readings can be caused by errors or inaccuracies in the engine tune itself.

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