cosy trav

iTrader: (1)

Ive got a problem with the ISCV , basically it isnt working . Tried a new one and thats the same , its just not opening up . Could this be an ECU fault . Ive tried both ISCV to the battery with and they both open then close when i take them off . Its on a L8 ecu , Not the loom as its a new RYAN loom , just doing my head in . What voltages should i have , im getting 13v when i test both connections to negative with the valve connected so theres power going through the solenoid . What voltage should i get if i unplug the valve and test across the pins ? im guessing it should be 13 v or there abouts but it isnt . All checks have been done when the engine is cold .Its had all new sensors about a year ago when i rebuilt the car and runs fine other than the ISCV .Any help would be appreciated .

OAP Pete

As EX Auto Elect [ Now retired, i can only tell you the Circuit to the ISCV... When engine running you should [ with the ISCV plug off Solonoid] have battery voltage to one terminal, the other terminal goes to ECU.. the ECU needs to see Water sensor for injection system [ rear of Head] to adjust idle...ie Cold to Hot.. Check the circuit. Sorry i cant help any more. If the Water sensor was "Duff" then you would be getting for sure more faults....ie High Fuel consumption... rough running... Check the Water sensor plug...and wiring back to ECU, Pete.

cosy trav

iTrader: (1)

Thats what i was thinking Pete , it does seem like an ecu fault maybe the power transistor or circuit is goosed . I will check the voltages over the weekend . It could even be the wiring is reverse polarity to the solenoid which would cause a major problem .

cosy trav

iTrader: (1)

Hows your car doing now Pete ? Your missed a bit off the rsoc 3dr secion you know . Get back on there .

martysmartie

iTrader: (1)

You should have 12V+ at one side, this comes from the fuel pump relay, the earth is pulsed via the ECU (PWM), so that part is not happening as you have power.

The input comes from multiple sources, the CTS as said as when cold it will open the ISCV to achieve a faster idle, the TPS can also effect the ISCV operation.

Martin

OAP Pete

Car is Fine thanks....back on full song now... Do check the 2 wires re-the Water sensor [ Blue ] right back to ECU, you have 12v on one wire of ICSV so thats OK, and as the other Gentleman said does come from Fuel pump relay, hope its not ECU...guess your have to borrow one to try ! Do remember when the water sensor used to fail....ie ..open circuit or wiring problem...you allways loose Fast idle...and engine stalling all the time till fully Hot.. Peter

cosy trav

iTrader: (1)

Just checked the voltage on the pins without it connected to the iscv im getting 12v on one to neg on battry and 5v on the other . With the iscv connected i get 12 v on both to the battery . How do you set the TPS up , what voltages should i have ?

cosy trav

iTrader: (1)

Just changed CTS is still the same .Wirings ok as the secs monitor is picking it up .

OAP Pete

To test TPS... very difficult to do on engine as you cant get at with meter. What i used to do is go to ECU unplug socket... being carefull you can un-screw the block which hold all the wires...pull out..[ carefull]...plug back in to ECU. This now allowes you to put + of your meter into pin 17...neg of you meter to earth. Ign on you should see 5v/4.5v....slowly open throttle..reading goes down to 0.5v on full throttle. Before doing this....WHEN SOCKET UNPLUGED you looking at the 35 pins, there is a longer line to the right, shorter line to the left. Pin [1] is the first in the longer line at the loom end...ie ..then pin [18] lower one...back to loom end again for pin [19] [ shorter row ] down to pin [35] so that will tell you where pin 17 is. Hope helps. While there you might as well check CTS, pins [29] and [11] you need.. with ohms only..

10deg C..........15 / 18K
20 : : ::::::::::::3 / 5K
50 : ::::::::::::: 950 ohms
80 : :::::::::::::: 300 / 400 ohms

Hope Helps OAP Pete.

cosy trav

iTrader: (1)

Cheers pete will try that tomorrow .

martysmartie

iTrader: (1)

Pin 17 is black and red IIRC it's on the top row of the two.

Martin

OAP Pete

Pin [17] .... Well looking at all my plans, which i used all the Time when i was working. Plug disconnected from ECU...looking at all 35 terminals, with the socket pointing downwards, right hand side is the longer row, Pin 17 ..2nd up from bottom.

Pete.

martysmartie

iTrader: (1)

Yes thats right as I say second row up of the two.

Martin

tabetha

Nothing at all to do with the CTS, this problem, if getting 12v one side and 5v the other side your valve is knackered, as it is not doing what it should do, even though getting the required input from the relay(12v) and the ecu(5v).
To test simply disconnect and drop your idle speed artificially low to almost stalling, now reconnect the iscv, this should pick the revs up to correct idle, as it only raises the rpm above the base setting, if it doesn't raise the revs and you have the correct input, then it's knackered.
Kicking the shit out of it with 12v direct from a battery will make most duff ones move, as they are overpowered big time like this.
The 5V from ecu is a pulse, which in a million years you won't see on a digi multi metre, as it simply can't capture the fast moving changes of lecky pulses, osciliscopes are used for this.
tabetha

cosy trav

iTrader: (1)

Tabs The 5v on the pin to earth is when the iscv is unplugged , when its plugged im getting 12v on both sides to earth . Tried another valve and its still not working . Going to try and check the voltages pete posted and try both valves on my mates escos .

cosy trav

iTrader: (1)

Tried both valves on my mates escos and there working , tried checking votage on pin 17 getting 0.3v with throttle closed , 4.8v with throttle open , is this right as its the opposite to what pete posted but im running L8 with 4x4 cosworth TPS .All wiring should be ok as its a new Ryan loom .

martysmartie

iTrader: (1)

That sounds right mate, your seeing the earth side of the ISCV when connected hence the 12V and when disconnected you see the ECU power as described below, it controls the valve by PWM.

One things for sure the valves are FINE, it's rarely the valves that are the problem, it's the ECU's inability to control them correctly due to receiving duff info.

The reading is correct for 2WD the voltage DECREASES with throttle, however as you have L8 the voltage should INCREASE with throttle, this is the very reason for swapping the wires of the PF01 TPS when people fit L8 on a 2WD car, you have PF09 but in any case it should still read the other way, I.E voltage increasing with throttle, I feel pretty confident in saying this could well be your problem.

Martin

cosy trav

iTrader: (1)

It is right then Martin as the voltage is increasing with the throttle opening .

Looks like it might be an ECU fault after all .

Next question , who repairs or tests ECU's ? Not getting it done yet as it isnt causing any major problem having the ISCV not working , its when its cold it idle's low .

Thanks for the advice so far .

martysmartie

iTrader: (1)

Sorry I misread your post, yes 4.8V at WOT is ok.

As to repairs I would try MSD, but eliminate everything else first.

It won't as thats really the only time ISCV is utilized for a cold start, the other time it can be needed is a heavy electrical demand etc.

Martin

OAP Pete

Yes my readings for you were re-standard ECU...Looks like L8 ECU opersite !, could it be your new loom being for standard ECU.
OAP Pete

martysmartie

iTrader: (1)

Don't think it's anything to do with the loom so far as I know there almost identical and it is giving the correct readings, if you have L6 loom and L8 ECU whilst keeping PF01 TPS then you have to swap the outer wires so as to reverse the output.

Martin