MPFI done but low idle at warming up
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Honda-Tech Member

Joined: Dec 2007
Posts: 273
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From: san jose, ca, united states
i just fixed my tps sencer wires but now it has low idle could it be the warming up valve in the back of the manifold? and also when i start it up it boggs down when i keep steping on the gas pedal then it revs up fine after that.
the fitv doesnt have any wires for clarifiation. it opens and closes from the coolant that passes through it. but it could be stuck closed. its located right under the throttle body. if you do a search there are writups on removing and inspecting it on here.
if you're using like an a6 intake mani and tb then you won't have a fitv. it is possible i would imagine that if the iacv was stuck closed all the time it might cause a low idle. is the idle always low or does it come up once the car is warmed up? it could simply be that the idle screw is set too far in.
try adjusting it
"Instructions to set the Idle:
-Warm the car up to operating temperature. This is generally determined when the radiator fan turns on if the car is stationary.
-Unplug the IACV valve on the back of the intake manifold. This needs to be done because the IACV valve is what the ECU uses to dynamically control the idle by allowing more or less air to bypass the throttle plate. Be careful not to burn yourself!
-Set the idle to 600rpm using the idle control screw. This screw controls the static amount of air that bypasses the throttle plate.
-Turn the car off and plug in the IACV valve.
-Reset the ECU. This needs to be done because the ECU will have thrown an ECU error code.
Restart the car. The idle should be running nice and close to 750 rpm."
try adjusting it
"Instructions to set the Idle:
-Warm the car up to operating temperature. This is generally determined when the radiator fan turns on if the car is stationary.
-Unplug the IACV valve on the back of the intake manifold. This needs to be done because the IACV valve is what the ECU uses to dynamically control the idle by allowing more or less air to bypass the throttle plate. Be careful not to burn yourself!
-Set the idle to 600rpm using the idle control screw. This screw controls the static amount of air that bypasses the throttle plate.
-Turn the car off and plug in the IACV valve.
-Reset the ECU. This needs to be done because the ECU will have thrown an ECU error code.
Restart the car. The idle should be running nice and close to 750 rpm."
check your plugs.
are you doing obd 1 swap? if yes, make SURE you are not using tps or iacv as the coolant tempt swtich ( i did that and after i switched it, idle problem went aawy)
make sure you got the FITV, TPS, and IACV at the right place.
http://www.nobodysuspectsthewagon.co...cm-wiring.html
theres the wiring diagram so make a double check.
3rd check timing either retard or advance.
Check your vaccum lines too.
other than that...thats pretty muich what i can come up with
are you doing obd 1 swap? if yes, make SURE you are not using tps or iacv as the coolant tempt swtich ( i did that and after i switched it, idle problem went aawy)
make sure you got the FITV, TPS, and IACV at the right place.
http://www.nobodysuspectsthewagon.co...cm-wiring.html
theres the wiring diagram so make a double check.
3rd check timing either retard or advance.
Check your vaccum lines too.
other than that...thats pretty muich what i can come up with
edited: B2 is ECU pin is for FITV, and if i remember right it was a blue wire.
http://hondaswap.com/reference-mater...pinouts-28667/
Last edited by r4BBiT; Mar 6, 2009 at 12:15 PM.
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I don't know about your FITV, but mine has to wires and its plugged in to the ECU. Also mine is not located under TB, its behind the IM on the oppposite corner of TB. First i didn't have it plugged in, because i had to use that pin for something else when i was doing MPFI swap, but afterwards i got a couple ECU plugs from junkyards and wired it in. There was a www with ecu wiring (or maybe it was in manual).
edited: B2 is ECU pin is for FITV, and if i remember right it was a blue wire.
http://hondaswap.com/reference-mater...pinouts-28667/
edited: B2 is ECU pin is for FITV, and if i remember right it was a blue wire.
http://hondaswap.com/reference-mater...pinouts-28667/
I'm talking about that thing on the right, one of the wires is blue, which according to this link http://hondaswap.com/reference-mater...pinouts-28667/ is Fast Idle Control Solenoid Valve. I might be wrong though 
Anyways work is done, time to go home

Anyways work is done, time to go home

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ON Cold start-up, my idle is stays too low and wants to die, it use to be at 2000rpm until it warmed
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Jun 10, 2008 06:11 PM




