How does the ecu calculate engine load?
How does the ecu calculate engine load?
Displacement, RPM, intake pressure.
Gxxgle this.
There is enough stuff…
So if the ecu sees TPS RPMS and MAP sensor readings correctly then it should calculate 100%
TPS doesn't matter for a load calculation. It uses displacement x rpm to calculate 100% theoretical airflow and the intake pressure to determine how much of the cylinder is actually being filled. If your talking about the PIDs listed in the scanner or scan tool for engine load/torque calculation take those numbers with a huge grain of salt.
Last edited by putts000; 01-04-2024 at 12:57 AM.
The jeep im workn on wont accelerate over 1800 in any gear (manual trany) and reads 30% engine load max but over 4500 n neutral
Let there be more information, this could be a hardware problem.
Otherwise log throttle and pedal to be sure it’s opening.
Maybe a log or the file can say more than words.
That issue doesn't sound like it's related to "tuning". Sounds more like the cat/exhaust is plugged up. Try pulling the upstream O2 sensors out and see if it changes.
Log a drive and share it here, then we may be able to spot a problem for you.
Its not the cat. already ck it. When you say hardware do you mean the ecu? the ecu sees tps as it should also map sensor readings as it should. I will post a log this weekend.
This issue sounds like a clogged fuel filter (I always forget to check those) or a vacuum leak. Try to test both then work your way to other things as creek-ranch said, your issue might be something mechanical. Best of luck
2010 Dodge Challenger SRT8 M6
Barton short throw shifter, aFe CAI, ARH Long Tube 1-7/8, CORSA Catback
401rwhp - 407rwtq
The log seems to show a limiting of/low manifold Kpa.
Check inlet and exhaust for restrictions.
Any mods or previous tuning done?
What is the manifold Kpa when engine not running? IE Barro.
A lot of full throttle in the log, is that the case?
The log file looks like the exhaust is restricted. At WOT manifold pressure should be equal to baro, jtec updates baro based on throttle angle and rpm, calculated for no throttle restrictions. There should be no restrictions to atmosphere in the intake and the least amount of residual pressure in the exhaust at WOT. Remove the upstream oxygen sensor and retest. In the log the longer you hold wide open throttle the more vacuum your building against a wide open throttle, excessive exhaust pressure is back feeding during valve overlap. Your O2 sensor is pulling fuel due to regurgitating inert exhaust gas that has no oxygen to burn. Does the exhaust have a really low grunty sound at WOT? If this was a fuel or spark issue the engine would be backfiring/detonating.
No restrictions in the intake system or the exhaust system. Removed the upsteam O2 sensor and no change. I actually checked the cat (with gauge) and intake system 1st thing when it come to me. Baro and map are the same key on engine off. Ive checked volt back probed at the ecu for map and tps. Ive already replaced the ecu and no change except engine show less with one ecu than the other. About 5% less. Also the ecu that I got was used. Ive replaced the air fllter tps sensor and map sensor.
What is the backpressure reading in psi while holding WOT for 5+ seconds? What are the map and baro readings in kPa with engine off and key on? What is you elevation? What are the sync counts on the crank and cam while running? What are the compression test numbers?
Last edited by putts000; 01-23-2024 at 10:29 AM.
Backpressure is less than 1 psi at wot. Baro is 98.9 MAP is 4.5 volts it dont show kpa reading. Elevation is 500 ft. One thing i did notice at wot is that baro slowly drops and when engine comes back to idle the brao does not come back up. Fuel status goes from closed loop to O/L drive at wot but once the baro drops fuel status stays in O/L drive at idle. Ive already replaced MAP sensor. Im going to try another one and see what happens
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