uberlawyer

Had the ISV cleaned, now the engine promptly stalls on ignition. Was working fine before ))))))))))

Connected the durametric, received errors 27 - IACV opening winding/IACV closing winding and 28 - IACV opening winding/IACV closing winding.

Cleaned the errors, disconnected the battery (well, the general connector), no joy.

ISV arrow is on top and pointing towards front of the car. ISV is humming continuously on ignition on.

Ideas? I'll have it cleaned again, maybe some dirt got dislodged and is preventing proper operation.

Durametric reports that ISV opened maximum 60% (last time 57%) on ignition. Does anyone know how much it should actually open?

techman1

I believe the arrow shows the direction of air flow, just verify you have it pointed in the correct direction.

mpruden

That stinks. Perhaps cleaning it somehow fried the electronics?

uberlawyer

@techman1: I know, but for Varioram I think it points towards the front of the car.

@mpruden: That's what I'm afraid of. Not only that it's not exactly cheap, but I'll have to have it shipped.

I would really help if someone could let me know how open it should be on ignition.

mpruden

With the durametric, can you run the ISV test "drive link." I believe that's what it's called with the Bosch Hammer.

On my car, with what I can only assume is a working ISV, you'll hear it click once every second or so while the test is running. Can you run a similar test with the Durametric?

Edit: I'm not sure how much it should open, but if the car is stalling, I can only think that it's currently "not enough."

This could be a combination of things. Perhaps an ISV that isn't opening enough plus a car that is in the process of relearning the proper idle speed since the battery has been disconnected. Does it always stall? What if you give it a little throttle once it starts? Can you keep it running then?

Rdelvalle

http://www.pistonheads.com/gassing/topic.asp?t=977858

After you clean it , when you shake it should rattle.

uberlawyer

@Rdelvalle: thanks for the link!

@mpruden: That's just what I did. Went to the service shop, started the car, then gave it some gas and kept it somewhere around 2,000 RPM.

Lifted after 1-2 minutes and it kept the idle, no problem. Shut it off, started it again - all is well. Idle oscillates between 840 and 880 RPM (as read by Durametric), just as before.

It will be interesting to see what it does tomorrow on a cold engine.

I also used the drive link function that you mentioned - it's called 'activations' in Durametric. The mechanic said he could hear a click.

I've tried activation on Varioram - nothing: not a click, buzz or anything. Does anyone know what should happen?

nine9six

Just outta curiosity, what did you clean your ISV with?
Carb cleaner has the chemicals that break down old fuel and gasses; brake cleaner does not. I do know that most like to use these chemicals interchangeably, but they are indeed different and so are their properties for cleaning.

After cleaning, the butterfly in the ISV should spin freely with very little compressed air...

uberlawyer

They've definitely used brake cleaner - I've asked that, too I have suggested carburetor cleaner, the mechanic was not very confident. I'll ask to clean it again using carb cleaner this time.

Good tip about the compressed air - thanks

JasonAndreas

Most 'brake cleaners" are acetone and you never want to let that get anywhere near your 993 (especially your painted brake calipers...) Depending on how they cleaned the ISV, it can work its way into the electrical motor portion of the ISV and start dissolving things.

coreseller

Not to be condescending, but did you reattach the electrical connection after reinstalling the ISV?

After cleaning mine I had a similar scenario as yours, turns out I indeed forget to plug it back in lol.

nine9six

Thanks for chiming in on this, Jason!

As far as brake cleaner on calipers; it took the clear coat right the eff off of the caliper. Now I dont use brake cleaner cept on non-painted or non-coated parts.

I'd tell them to please stop using brake cleaner on the ISV, unless they are willing to pony up for a new valve, in the event it starts melting stuff.

Of course the mechanic now has plausible deniability, since you brought the car in to have the ISV cleaned...

pp000830

My gut feel is that you have it in backwards or the plug connector on it needs cleaning as the part tends to be very durable and should last the life of the car.

For future reference brake cleaner & carb cleaner are both made with petroleum distillates that can be hard on electrical plastic parts and wire insulation. I use electric motor cleaner. It seems to work well without the potential damage.
Andy

bjornebo

I also did this once...

uberlawyer

@JasonAndreas & nine9six: Thanks for you suggestions, duly noted.

Surely reconnected: as indicated above, it is humming and Durametric reads its opening position.

I am pretty confident it’s not backwards. Since it’s Varioram, the arrow should be pointing towards the front of the car. Good tip on the electrical connector.

I should find out more today and update accordingly.