Guide: DIY Cleaning your 7MGTE ISCV

[RObErT_RaTh]

DIY: Cleaning your 7MGTE ISCV
by RObErT_RaTh aka Stumpy

Disclaimer: I take no responsibility for any damage or harm you may cause to youself or your car while following this guide. I've put it here just to help some people have more of an idea what to do and what is involved. If you don't feel confident enough then leave it to your local mechanic.

Time frame: ~2 hours if you're noob like me and take ages to do anything

Reason for this guide: I recently developed some really poor idling in the colder weather and when clutching in slowing down for lights / traffic etc my idle would drop so low that the car would stall when I'm still moving along. Not a good thing when you lose power steering and things I'd read around that this can be a big help and decided I'd give it a shot and now the car idles sweet when it's cold and no more issues! Much better than heel-toe revving at the lights with people looking at you strangely just because you dont' want your car to stall

Tools / Materials Required:
-12mm Spanner AND/OR 12mm Socket
-Pliers AND/OR Vice Grips
-Philips head screwdriver
-Gasket material
-Sharp cutting knife / scissors
-Torch/light depending
-Multimeter
-RP7 / WD40 etc
-Some commen sense

First thing I decided to do before I embarked was to read up on the TSRM and see what it had to say about my ISCV

http://www.cygnusx1.net/Supra/Librar...ction=FI&P=106

I also did some searching on these forums and found this previous guide by Lambolica most useful as well but since it showed pictures for a 1G-GTE I figured I'd still do a write up specifically for the 7M-GTE

http://toymods.net/forums/showthread.php?t=3535

Step 1: Locate your Idle Speed Control Valve (ISCV) and unplug the 6-wire electronic connector.



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IF YOU HAVE A STRUT BRACE LIKE MINE REMOVE IT NOW FOR EASIER ACCESS
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Step 2: Use some pliers or some vice grips to loosen and slide the hose clamps surrounding the hoses going in and out of the ISCV. Some of them are a bit tricky to get to and I don't have any pictures of this stage but you should be able to loosen them all with a little bit of persuasion. There is 1x larger air hose and 2x smaller coolant hoses. You can completely disconnect the larger air hose at this stage if you wish but when removing the smaller coolant hoses I recommend you shove a rag in around the surrounding areas to catch the small amount of coolant that will come out. I didn't find it neccessary to drain my entire system but you might feel otherwise. I managed to remove the air hose and 1x coolant hose with the ISCV still mounted but to remove the last one I had to unbolt the ISCV.

Step 3: Use a 12mm spanner or socket to undo the 2x bolts mounting the ISCV to the intake chamber. The top one is easy to get to but the one underneath will require a certain length extender on your socket to be able to access it easily. I couldn't fit a ratchet spanner in there because it was hitting the Throttle Position Sensor (TPS) and I couldn't get any movement side to side (Also unplug your TPS for easier access). All my socket extenders were too long but I ended up using a combination of my breaker bar and one particular socket which reached about right and I was able to slowly undo the bottom bolt.

Step 4: Once you've removed the bottom bolt you can move the ISCV around more freely and it's easier now to reach the bottom coolant hose and disconnect it, remember again a small amount of coolant will flow out. Be sure not to splash it into your intake chamber. Once removed your ISCV should look something like this:



As you can see from the pictures it is quite dirty and I also noticed that my coolant line in the ISCV was completely blocked off with crap!



You can use a small sharp object to poke around and loosen it and then I used a can of compressed air to blow all the gunk out.

Step 5: If you're following the TSRM now would be a good time to check your ISCV and make sure that you atleast have the correct resistance between test points where the connector plugs in.

http://www.cygnusx1.net/Supra/Librar...spx?S=FI&P=107

Following TSRM I measured ~22 Ohms between all the points and they recommened between 10 and 30 Ohms so that's a good result. I didn't take the testing any further than that but you can test the other functionality if you wish.



Step 6: Take your philips head screwdriver and undo the 3 screws holding your ISCV together. You don't have to worry about any springs shooting out at you or anything. Once apart you will clearly be able to see how dirty it is and why it needs cleaning so bad.



On the above housing on the left there is a rubber seal around the top so I removed this before cleaning as the chemicals can be harmful to the seals. I used RP7 (other people use WD40 etc) and a clean cotton cloth to clean the inside of the left housing and the black tip of the solenoid on the right. I also stupidly forgot to take a photo after it was cleaned but it should be all nice and shiney and free from black gunk.

Step 7: Once you've cleaned both parts you can replace the rubber seal and screw it back together. Here's a shot from underneath to show how it looks now:



Step 8: Since we removed the ISCV from the intake champer we've broken the seal on the gasket and because of this I decided to remove mine and replace it with a new one. I used a sharp hobby knife to remove the old gasket material from the intake chamber and got some standard gasket material, traced out the shape, and cut up a fresh one. Again I don't have any pictures of this I'm afraid but it's pretty simple stuff to figure out.

Step 9: Once you've made your gasket and you've got your ISCV all back together you can install it back on your 7M-GTE! First off I'd try and connect the bottom coolant hose to the ISCV and begin screwing it back onto the intake chamber. The other coolant line and air hose should be able to slide back on with the ISCV in place. Once it's all bolted in tight and all your hoses are connected don't forget to plug the connectors back in for the ISCV and also the TPS if you disconnected that too.



That's it! You're all done! Go and enjoy your 7M and rest easy it will idle smooth and be trouble free for a little while longer and enjoy the fact you saved some cash doing it yourself and learnt a thing or two along the way

[Kedderz]

done this many a time on the 7m(s) that ive owned, wd mate +rep

[RObErT_RaTh]

done this many a time on the 7m(s) that ive owned, wd mate +rep

Cheers buddy You must be a pro at it by now Also I hear these ISCV's aren't cheap to try and get through toyota so it's nice to know a little maintenance can save a lot of heartache and money