doing a 7mgte swap, have a few questions

cre · 07-06-2010, 03:33 AM

The pigtail coming out of the pre89 GTE TCCS (ECU) is for the HAC sensor (High Altitude Compensation)... it's essentially a clumsy MAP (Manifold Absolute Pressure) sensor which is used to help adjust fueling when there are significant changes in air pressure. You can run without one if you live at sealevel... if you live at a higher altitude you'll be fine too as long as your dialy driving doesn't involve a lot of changes in altitude, but you will be running richer than you need to and your gas mileage will suffer a bit.

I don't to gibberish....

....except for when I do.

07-06-2010, 03:33 AM	#7
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The pigtail coming out of the pre89 GTE TCCS (ECU) is for the HAC sensor (High Altitude Compensation)... it's essentially a clumsy MAP (Manifold Absolute Pressure) sensor which is used to help adjust fueling when there are significant changes in air pressure. You can run without one if you live at sealevel... if you live at a higher altitude you'll be fine too as long as your dialy driving doesn't involve a lot of changes in altitude, but you will be running richer than you need to and your gas mileage will suffer a bit. I don't to gibberish.... ....except for when I do. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->