I'm looking for help in diagnosing high EGTs on a S/C engine only when under load. Here's the scoop:
Normally, during the summer, my EGTs under load with a trailer in tow runs between 1300 and 1425 F (max) when going up 5-8% grades at 65-75mph. I've noticed that the EGTs I'm seeing now are running 1300-1450 under mild loads without a tow at the same speed or less, and with temperatures significantly lower than during the summer.
On flat grades, I used to run just under 1200...now run just over 1200. So the difference here is not much, expect that I would have expecte somewhat of a lower temp due to ambient temperatures.
The "problem" seems to be noticable only when really under load.
Initiall thoughts are:
1) lean-run condition leading to high EGTs...why? Fuel filter is less than 1yo. Regulator?
2) dirty air filter leading to constricted air flow (should not result in lean condition due to ECU and MAF correction?). Beats me.
I'm conflicted here.... I do not know enough about the LC computer and just what would cause a S/C engine to run high EGTs. I can see reasons why both a rich or lean condition would lead to high EGTs, but it always ends up being something the ECU or MAF should correct for if I understand it right... ???
If you have any idea or (preferably) knowledege of why this would happen, please let me know...
Tom
Normally, during the summer, my EGTs under load with a trailer in tow runs between 1300 and 1425 F (max) when going up 5-8% grades at 65-75mph. I've noticed that the EGTs I'm seeing now are running 1300-1450 under mild loads without a tow at the same speed or less, and with temperatures significantly lower than during the summer.
On flat grades, I used to run just under 1200...now run just over 1200. So the difference here is not much, expect that I would have expecte somewhat of a lower temp due to ambient temperatures.
The "problem" seems to be noticable only when really under load.
Initiall thoughts are:
1) lean-run condition leading to high EGTs...why? Fuel filter is less than 1yo. Regulator?
2) dirty air filter leading to constricted air flow (should not result in lean condition due to ECU and MAF correction?). Beats me.
I'm conflicted here.... I do not know enough about the LC computer and just what would cause a S/C engine to run high EGTs. I can see reasons why both a rich or lean condition would lead to high EGTs, but it always ends up being something the ECU or MAF should correct for if I understand it right... ???
If you have any idea or (preferably) knowledege of why this would happen, please let me know...
Tom