91 civic dx with y7 swap

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importphanatic94vx

New Member
i have a 1991 civic hb dx with a d16y7..i am running the stock d15b2 intake manifold till i wire up the mpfi when i get the y8 head..the motor keeps reving up to 1,500rpm then back down to like 950rpm..it does this all the time..i unplug the MAP sensor and then plug it back in when the motor is running then it quits.as soon as i shut the motor off and start it back up it start to idle up and down again..so i unplug the map while its running and plug it back in it runs perfect.i am running the obdo wiring and ecu..please help me




thanks alot d
 
importphanatic94vx said:
i have a 1991 civic hb dx with a d16y7..i am running the stock d15b2 intake manifold till i wire up the mpfi when i get the y8 head..the motor keeps reving up to 1,500rpm then back down to like 950rpm..it does this all the time..i unplug the MAP sensor and then plug it back in when the motor is running then it quits.as soon as i shut the motor off and start it back up it start to idle up and down again..so i unplug the map while its running and plug it back in it runs perfect.i am running the obdo wiring and ecu..please help me
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are you unplugging the MAP or the EACV? if you unplug the EACV (on top of intake manifold on driver's side with green 2-wire connector) you should get a check engine light (code 14), the idle should drop down to around 500-600rpm and remain steady - if it does, the EACV is working correctly and you need to look elsewhere - make sure the engine is completely full of coolant with all of the air bled out of the system (including the heater)
 
jlicrx said:
are you unplugging the MAP or the EACV? if you unplug the EACV (on top of intake manifold on driver's side with green 2-wire connector) you should get a check engine light (code 14), the idle should drop down to around 500-600rpm and remain steady - if it does, the EACV is working correctly and you need to look elsewhere - make sure the engine is completely full of coolant with all of the air bled out of the system (including the heater)
Click to expand...

he's right. itll rev that way when theres air in the coolant system. mines actually doing the same and i have a small coolant leak.
 
My buddys stock 90 rex does this and its the IAC sensor.
 
still idles weird

ok replaced the map sensor and the idle air valve..still fluxuates 1,300rpm down to 950 rpm then back up..like i said i pull the plug on the map sensor well its runing and plug it back in it runs perfect ..soon as i shut the key off and start it back up..idle goes back to fluxuating..


help help
 
ok

ok if resetting the ecu does not work what is next..there is a sensor below the intake that i heard was callled the cam positioning sensor that is unpluged..its right below the intake /....the b2 block has two wirres the y7 has a one wire sensor..
 
That could be it. My buddys car dident run right cause that wasent pluged in but it still has the IAC sensor out so it does the rpm fluctuating still.
 
I have no idea. you could alwase test to see what wires you should use.

Try them one at a time and see what wire combos will clear it up.
 
help help

hooked up the sensor below the intake think it was the cps..still idling weird..up down,,,up down...up down..pissen me off..help help help
 
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