need 240 wiring diagram for idle control valve

green 1992 245 b230f --- stock

idle is very bad, shaking side to side

brand new genuine volvo motor mounts
stock m47 volvo tranny mount --- good condition

using electronic vacuum leak test --- passed. perfect. zero leaks
using vape smoke test into intake side --- passed. zero smoke leaks

disconnected the idle control valve --- nothing happens. zero effect. bad idle continues

swapped ICV with my other stock white 240 b230f

1. icv from the green 245 works perfectly on the white 240

2. the working icv from the white 240 into the green 245 --- results to bad idle on the green 245

in short: both ic valves work perfectly on the white 240 , but both do not work at all on the green 245

both engines are stock b230f

therefore --- must be a wiring issue on the green 245

my mechanic friend can trouble shoot the green 245 but says he needs the wiring diagram for the icv

a. where can I obtain this wiring diagram for a stock b230f 240/245

b. any other ideas of the source of this bad idle before we go on a ghost hunt via the wiring diagram?

thanks in advance

andrew

This assessment is a questionable cause logical fallacy.

You have bad idle and therefore assume that your IACV has a wiring issue but have you confirmed a number of other issues that would cause idle problems?

Are you implying that your idle is low? Does your AC function? Is your TPS adjusted properly and functioning? Is your throttle body and plate cleaned? Are any codes being stored? Have you reset the LH ECU at any point? Have you run the IACV diagnostic testing in the LH OBD system? Don't just start hacking a wiring harness because you assume your IACV isn't getting proper power... lets find out WHY it isn't. It may well be the wiring, but there are plenty of stops along the way worth checking.

I'd start with cleaning your TB and plate, checking your TPS for proper adjustment, tell us what your idle really is (though you might not have the tach now that I think of it) are you auto or manual, AC or not, and of course... run the LH OBD test to SEE/HEAR if your IACV can in fact be controlled by the ECU.

+1


After you do the above, check for vacuum leaks. Don't forget the intake manifold gasket.

EivlEvo said:

This assessment is a questionable cause logical fallacy.

You have bad idle and therefore assume that your IACV has a wiring issue but have you confirmed a number of other issues that would cause idle problems?

Are you implying that your idle is low? Does your AC function? Is your TPS adjusted properly and functioning? Is your throttle body and plate cleaned? Are any codes being stored? Have you reset the LH ECU at any point? Have you run the IACV diagnostic testing in the LH OBD system? Don't just start hacking a wiring harness because you assume your IACV isn't getting proper power... lets find out WHY it isn't. It may well be the wiring, but there are plenty of stops along the way worth checking.

I'd start with cleaning your TB and plate, checking your TPS for proper adjustment, tell us what your idle really is (though you might not have the tach now that I think of it) are you auto or manual, AC or not, and of course... run the LH OBD test to SEE/HEAR if your IACV can in fact be controlled by the ECU.

Click to expand...

ok lets go through that list slowly:

Are you implying that your idle is low? --- nope, not implying. after I unplugged the iacv nothing happens. so that is a strong sign that I should pursue that furthr , hence my posting

Does your AC function? --- entire AC system deleted. all parts removed, very cleanly done. could this have something to do with this bad idle? I might have missed something

Is your TPS adjusted properly and functioning? --- I HAVE NO IDEA

Is your throttle body and plate cleaned? ---- very clean. engine was out of the car and disassembled except for the head. everything is brand new

Are any codes being stored? --- car has no black box tester for codes

Have you reset the LH ECU at any point? --- I HAVE NO IDEA WHAT THAT IS

Have you run the IACV diagnostic testing in the LH OBD system? --- NOPE, BECAUSE I DO NOT KNOW HOW TO

Don't just start hacking a wiring harness because you assume your IACV isn't getting proper power... lets find out WHY it isn't. It may well be the wiring, but there are plenty of stops along the way worth checking. --- fully agree with you

I'd start with cleaning your TB and plate, --- done

checking your TPS for proper adjustment, --- HOW DOES ONE ADJUST THE TPS?

tell us what your idle really is (though you might not have the tach now that I think of it) --- idle is sawing the engine left to right by more than one inch, but when I rev it smoothens out

are you auto or manual, --- m47, new oil, very good condition mount

AC or not, --- AC deleted

and of course... run the LH OBD test to SEE/HEAR if your IACV can in fact be controlled by the ECU. --- please tell me how to do that. please please please

plug wires --- checked. all sending spark

thanks in advance

andrew

Go to volvowiringdiagrams.com and down load the green book for LH2.4. It tells you how to do everything you are asking about. It has easy to read troubleshooting flow diagrams for every possible failure in the fuel system.

Lando said:

Go to volvowiringdiagrams.com and down load the green book for LH2.4. It tells you how to do everything you are asking about. It has easy to read troubleshooting flow diagrams for every possible failure in the fuel system.

Click to expand...

thank you lando

andrew

If it's a '92, it's got either 2.4 or 3.1 and it absolutely has a black box tester unless someone removed it. Inside the driver's side fender, up on the back side of the strut tower. It's pretty small, maybe 2"x3".

ok lets go through that list slowly:

Are you implying that your idle is low? --- nope, not implying. after I unplugged the iacv nothing happens. so that is a strong sign that I should pursue that furthr , hence my posting I'm trying to figure out which problem you've got and are trying to solve. Just because your idle doesn't change when you unplug your IACV doesn't mean that it's bad... there are some other variables at work here.

Does your AC function? --- entire AC system deleted. all parts removed, very cleanly done. could this have something to do with this bad idle? I might have missed something The reason I asked about this is because if you have LH2.4 (I don't know about 3.1) the AC switch/relay sends a signal to the ECU to increase the idle speed during compressor operation.

Is your TPS adjusted properly and functioning? --- I HAVE NO IDEA lol well dude, you've got to check! The throttle position switch is on the firewall side of the throttle body (it's a black bosch thing usually) with the engine off, if you manually open the throttle plate, you should hear/feel it clicking. That might lead you to it. Also... the wires for it come out of the same harness for the IACV. iirc it's IACV, starter and the TPS.

Is your throttle body and plate cleaned? ---- very clean. engine was out of the car and disassembled except for the head. everything is brand new Good, but just consider that new doesn't always mean working or adjusted. Let's sideline this for now though.

Are any codes being stored? --- car has no black box tester for codes As was mentioned, if you have a stock ECU on this car it's either 2.4 or 3.1. Both of these are OBD1 and have a black box for diagnostics under the hood on the intake side strut tower. It has it's own connectors

Have you reset the LH ECU at any point? --- I HAVE NO IDEA WHAT THAT IS The engine control unit (ECU) is your fuel computer. You need to check codes that might be stored in that aforementioned black box. Have you gotten any check engine lights? You can also "reset" this all by disconnecting the battery for a few minutes BUT we should maybe diagnose before we just do the battery.

Have you run the IACV diagnostic testing in the LH OBD system? --- NOPE, BECAUSE I DO NOT KNOW HOW TO First. It might be worth while to go into your passenger (right side) footwell in the car and remove the kickplate that's just ahead of the door. You'll find your fuel ECU there and under the knee bolster cover thingy in the same spot you'll find your EZK (ignition computer). Grab the numbers off of these and you'll then be able to find out which LH system you've got... might help with all this diagnosis.

Don't just start hacking a wiring harness because you assume your IACV isn't getting proper power... lets find out WHY it isn't. It may well be the wiring, but there are plenty of stops along the way worth checking. --- fully agree with you

I'd start with cleaning your TB and plate, --- done

checking your TPS for proper adjustment, --- HOW DOES ONE ADJUST THE TPS?

tell us what your idle really is (though you might not have the tach now that I think of it) --- idle is sawing the engine left to right by more than one inch, but when I rev it smoothens out Do you have a tachometer though? A redblock vibrating side to side isn't good, but that might not be an idle issue... it could be a balance issue as well

are you auto or manual, --- m47, new oil, very good condition mount

AC or not, --- AC deleted

and of course... run the LH OBD test to SEE/HEAR if your IACV can in fact be controlled by the ECU. --- please tell me how to do that. please please please

plug wires --- checked. all sending spark

thanks in advance

andrew

Pull the intake hose and check for leaks.

I use a smoke machine.

Double check for vacuum leaks(manifolds, hoses/lines), clean grounds, conduct a wiggle test on your IACV and TPS as well as your knock sensor under your intake manifold. A poor connection could cause this and with a vacuum leak can cause a rough idle. Green Books are your friend, to double tap with Lando, Green Books galore