unplugging an o2 sensorr, Defaultt lean ? - Great Lakes 4x4. The largest offroad forum in the Midwest

Mclovin · May 9th, 2006, 08:28 PM

does the ECU go to lean default when o2 is unplugged ? or is default rich ?
Its an 88 chevy TBI 350 truck motor

MuddyPaws · May 9th, 2006, 09:24 PM

It goes to a default set of parameters. Now if it is cold and tha air is dense, then it will ne a bit on the lean side. If it is hot and the air is thinner then it will be running a bit rich. It will not adjust for temp, pressure, or load changes. So there is no real answer to your question.

Mclovin · May 9th, 2006, 11:25 PM

Hmmm ok.. got any ideas on how to make the computr lean it out more..
on a side note: i have the Holley TBI unit and i know they're headaches but with my heads i need the extra CFM.. just not all the fuel..

I know this makes no sense

auburn6887 · May 17th, 2006, 10:31 PM

did you plug the holley into the oem wiring to the oem computer? if so just get a new tbi chip for your motor.ebay $15 i think it was tbichip. i told him what i did. on the tps sensor you should read .500 volts at idle. you can oblong the holes to make the tps read it is open farther and you will run richer.

Mclovin · May 17th, 2006, 11:37 PM

Quote:

Originally Posted by auburn6887

did you plug the holley into the oem wiring to the oem computer? if so just get a new tbi chip for your motor.ebay $15 i think it was tbichip. i told him what i did. on the tps sensor you should read .500 volts at idle. you can oblong the holes to make the tps read it is open farther and you will run richer.

I need to lean it out not dump more fuel in.. Im gona try and find a stock TBI unit to put on and see if that helps...

May 9th, 2006, 08:28 PM	#1
Mclovin "The Situation" Join Date: 11-07-05 Location: Dearborn Heights, Mi Posts: 14,336 iTrader: (15)	unplugging an o2 sensorr, Defaultt lean ? does the ECU go to lean default when o2 is unplugged ? or is default rich ? Its an 88 chevy TBI 350 truck motor

May 9th, 2006, 09:24 PM	#2
MuddyPaws Boink Join Date: 11-05-05 Location: Sault Sainte Marie Posts: 10,977 iTrader: (12)	It goes to a default set of parameters. Now if it is cold and tha air is dense, then it will ne a bit on the lean side. If it is hot and the air is thinner then it will be running a bit rich. It will not adjust for temp, pressure, or load changes. So there is no real answer to your question.

May 9th, 2006, 11:25 PM	#3
Mclovin "The Situation" Join Date: 11-07-05 Location: Dearborn Heights, Mi Posts: 14,336 iTrader: (15)	Hmmm ok.. got any ideas on how to make the computr lean it out more.. on a side note: i have the Holley TBI unit and i know they're headaches but with my heads i need the extra CFM.. just not all the fuel.. I know this makes no sense

May 17th, 2006, 10:31 PM	#4
auburn6887 Newbie Join Date: 03-28-06 Location: detroit Posts: 14 iTrader: (0)	did you plug the holley into the oem wiring to the oem computer? if so just get a new tbi chip for your motor.ebay $15 i think it was tbichip. i told him what i did. on the tps sensor you should read .500 volts at idle. you can oblong the holes to make the tps read it is open farther and you will run richer.