TPS adjustments, unclear on voltage readings.

Nathaninwa · 01-22-2012, 04:25 AM

So got the truck fired up today. Pretty much like I shut it off yesterday, but its been 10 months and an intake/ecu wap later! Have my wideband installed and the thing ran really lean at idle. I played with the flapper door bypass screw and rotated the spring setting. At first it had a hard time idleing lean in the 17's for afr, had to loosen the door to get it to come down to low 15's at idle, but now the door is so loose the arm does not turn the fuel pump off anymore?

Seems weird since Im running an 87 ecu which is tuned around the 295cc injectors, and I have the later Cressida 315cc injectors. Base timing is at 10*, TPS is properly setup by grabbing the voltages at the ECU.

Im going to get it out on the road tomorrow to see how it drives, and tune the afm more. Ill be checking the VF signal and keeping an eye on AFR's while cruising to try and target the 2.5 volt VF (zero fuel trim) and see what wot is as well. Im bothered by the idle tune at this point.

Is there anyway I can wire in a heated O2 and have closed loop idle, or does the early (87 ecu) not go closed loop idle?

One more question. How is the crankcase vent supposed to be routed on an NA setup. Mine is setup like the Turbo system, gos from the valve coves to the TB so full engine vacuum is on the case at all times. There is a restrictor inline in the system like stock too. There is so much vacuum in my case that I get seal squeel, at first it sounded like a throwout bearing going bad. So for the last couple years I have had a small hole drilled into the fill cap. I dont think this is enough to significally lean out the mixture, but it is unmetered air.

01-22-2012, 04:25 AM	#29
Nathaninwa Intake Join Date: Jun 2011 Location: Aberdeen, WA Posts: 43	So got the truck fired up today. Pretty much like I shut it off yesterday, but its been 10 months and an intake/ecu wap later! Have my wideband installed and the thing ran really lean at idle. I played with the flapper door bypass screw and rotated the spring setting. At first it had a hard time idleing lean in the 17's for afr, had to loosen the door to get it to come down to low 15's at idle, but now the door is so loose the arm does not turn the fuel pump off anymore? Seems weird since Im running an 87 ecu which is tuned around the 295cc injectors, and I have the later Cressida 315cc injectors. Base timing is at 10*, TPS is properly setup by grabbing the voltages at the ECU. Im going to get it out on the road tomorrow to see how it drives, and tune the afm more. Ill be checking the VF signal and keeping an eye on AFR's while cruising to try and target the 2.5 volt VF (zero fuel trim) and see what wot is as well. Im bothered by the idle tune at this point. Is there anyway I can wire in a heated O2 and have closed loop idle, or does the early (87 ecu) not go closed loop idle? One more question. How is the crankcase vent supposed to be routed on an NA setup. Mine is setup like the Turbo system, gos from the valve coves to the TB so full engine vacuum is on the case at all times. There is a restrictor inline in the system like stock too. There is so much vacuum in my case that I get seal squeel, at first it sounded like a throwout bearing going bad. So for the last couple years I have had a small hole drilled into the fill cap. I dont think this is enough to significally lean out the mixture, but it is unmetered air.