|
|
|
|
|
#1
03-11-2010, 01:06 PM
|
|||
|
|||
|
Voltage to ICV?
First, forgive me for starting yet another thread on this topic (high idle), as I'm doing everything i can to prevent taking to shop - while also learning about my car. Have spent weeks studying posts but not sure Im making any progress.
Just installed remfg Idle Control Unit and idle still varies from 800 - 1500 rpms. Seems to idle fine when first started, but rises when it reaches operating temp. Checked voltage at Idle Control Valve (pulled back connector to reveal pins) and it's reading 0. HOWEVER, if I totally remove conector to ICV, idle surges. Since it surges, wouldnt this mean there is power to ICV? If I disconnect ICU, idle surges. Maybe wiring between ICU and ICV is shorted? I've put 9v battery to ICV pins and can hear audible click. I also disconnected oil temp sensor - no change. And vacuum lines seem ok. I'm stumped again. Ragtopper 1982 380SL 
|
|
#2
03-12-2010, 12:17 PM
|
|||
|
|||
|
It could be the wiring from the idle relay to the valve. That's easy enough to test.
You should also check that the relay has power (pin 2) and ground (pin 4). The relay gets power from the overvoltage protection relay.
__________________
Chuck Taylor Falls Church VA '66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe
|
|
#4
03-12-2010, 02:08 PM
|
|||
|
|||
|
Correct, relay = ICU.
Those are the correct test points. I just looked in the testing section, and it says and I quote "approx 12v between jacks 2 and 4." If you want a copy of this section off the CD, send me an email. Sounds like you have a bad OVP relay or wiring, and the ICU isn't getting enough power to operate.
__________________
Chuck Taylor Falls Church VA '66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe
|
|
#5
03-20-2010, 11:08 AM
|
|||
|
|||
|
update
Bought new OVP relay from MB dealership ($100). Plugged it in and no change. Still idles around 1100 rpms when warm.
Checked new relay and NO voltage to ICU. (fuse good) Plugged in OLD ovp relay and still feeding 7 volts to ICU. I guess dealership sold me bad OVP? Ragtopper 1982 380SL
|
|
#6
03-20-2010, 03:22 PM
|
|||
|
|||
|
What voltage are you getting to the OVP relay? Is there corrosion in the socket?
__________________
Chuck Taylor Falls Church VA '66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe
|
|
#9
03-20-2010, 04:17 PM
|
|||
|
|||
|
Something flakey in one of the wires or the sockets. Do some shaking and wiggling of wires to see if you can identify it.
If you look at p. 108 of the wiring diagram, the OVP gets its power on on pin 1, big black/red wire from connector c105. That's the big terminal on the right hand inner fender. I think that bad boy is fed directly from the battery.
__________________
Chuck Taylor Falls Church VA '66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe
|
|
#11
03-20-2010, 08:41 PM
|
|||
|
|||
|
My opinion is that that's not enough juice to get the ICU to function right. The spec is 12v. I think you need to find out why the OVP input voltage is low. You should have very close to battery voltage at pin 1.
Suggest y measure your at the big lug on the right fender, then check C105 for corrosion, and test the black/red wire for resistance.
__________________
Chuck Taylor Falls Church VA '66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe
|
|
#14
03-21-2010, 03:52 PM
|
|||
|
|||
|
What voltage are you seeing across the battery posts with the engine running?
__________________
Chuck Taylor Falls Church VA '66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe
|
 |
| Bookmarks |
|
|
Linear Mode
