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running peg rich at cruising speeds? help!


2fast2six
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Closed loop is when the ECU is using the o2 sensor to control fuel. Since the old narrow band sensors are only accurate in one place, 14.7 AFR, the ECU actually richens and leans the mixture so its constantly crossing over the accurate spot and on your wideband it would appear to be oscillating from maybe 14.2 to 15.2 AFR at cruise, constantly. That's closed loop control. Do you still have the factory O2 sensor hooked up?
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its a 1987 .no im just running the wideband sensor in the spot where the oem o2 sensor was and it never seemed to be an issue before.. and i believe the injector clips are in the right spot. im at work right now but i believe the black injector is closest to drivers side fender... blue/greenish one is towards passenger side
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so you do away with the factory 02 sensor and then wonder if the ecu is in open loop hum

 

that wide band sensor ain't gona last long in the oem 02's position , too hot for it

you want it about 12-14" down the down pipe just above the turn

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ok first get an oem 02 sensor or a 3 wire and install that,, remove the wide band sensor and save for a new location further down the exh down pipe

behind the abs unit on the fire wall you should see a single wire grommet this is the ecu 02 sensor signal wire , connect the 02 signal wire to this wire , be careful the wire is shield'd so make sure you do not short out the signal

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ok first get an oem 02 sensor or a 3 wire and install that,, remove the wide band sensor and save for a new location further down the exh down pipe

behind the abs unit on the fire wall you should see a single wire grommet this is the ecu 02 sensor signal wire , connect the 02 signal wire to this wire , be careful the wire is shield'd so make sure you do not short out the signal

what he said... also check your cts and isc, they'll make it run rich also
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took out the wideband sensor and put in a stock o2 sensor. same problem. nothing changed... could a bov sticking or not working correctly cause this problem? how can i tell if injector clips are backwards? Edited by 2fast2six
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:rolleyes: unplug both injs clips,, plug one at a time onto the pri inj, when the engine starts you have the clips right , now once you know what clip is what,, mark them so you can id them at a later date

 

pri inj is blk and towards the drivers fender

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the enigne starts now.. and runs it just gets too much fuel under light driving throttle or not enough fuel under hard on the throttle.. maybe i should check on the cts. which one is it in the intake

it's the verticle two prong sensor. Disconnect your battery, unplug it, reconnect your battery then take it for a drive... It'd probably be good to disconnect your ISC at the same time, that nose switch goes bad and sends the computer all kinds of weird stuff. When they are disconnected the computer throws them in closed loop, so it will assume everything is perfect. If it's not that probably a leaky injector or something
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people one more time READ the How the System works in the beginning of the FUEL chapter in the FSM

if you do not understand how the system works and what part does what ,, you will NEVER get it running properly

 

it's only 20 minutes worth of read time but it will save you weeks worth of time

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i tried swapping the injector clips.. seemed to not change anything. i unpluged the cts sensor and it seemed to run alot better. gunna try and swap out a differnt cts and see what happens

 

swaping both inj clips tells you NOTHING , the engine is running on ONE inj only,, which inj clip is it running on

and is one or more inj stuck open,, your going to have to do some real work here and see whats going on , remove the inj top cap KEEP the injs in place , they will blow out of place from the pressure if you do not and spray gas every where , use some heavy string or wire to tie the injs in place , run the fuel pump by way of the fuel pump test connector and a jumper to the batt posi terminal,, check both injs for fuel leaking also check the pressure regulator hose for fuel leaking out of it ,, while at it check the letters on the injs to make sure the proper inj's are install'd

 

you can find your problem with in 10 minutes if you realy want to

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