Hi all,
I had a slight problem with the idle speed when air con was on.
Car didn't stall or anything like that it just idled a bit rough at 600 rpm. ( RPM drops in gear, but ISC IS GOOD)
I rang a mechanical group I won't use names but they are Australia wide.
They said "could be the ECU", and they could check it and also set the base idle.
So I wanted to get the idle perfect,, and I agreed to take it too them. They took out the ECU and took off it's cover , BUT they really won't sure,, a lot of humming and haring.
Anyway they proceed to go ahead and set the base idle. They cleaned the throttle body still ON the engine just sprayed a heap of carby cleaner in it and wiped it with a rag. Then started it up,,and revved all the shit out smoke every where. Now it's idling at about 2000 rpm the motor is already HOT so it's not a cold start. He turned the idle screw all the way in and it is now at about 1200 rpm
Him and his boss are walking away from me talking about what it could be. They come back disconnect the battery this didn't work. I said "it's the fast idle valve it must have shit stuck in it",,
AS THE IDLE SCREW IS ALL THE WAY IN,,and theoretically the engine should now stall with that screw all the way in. They ask me if I want to leave it with them and they will fix it at my expense. I just laughed and said "Yea right you guys will charge me a gujillian DOLLARS,,no thanks"
I bitched and moaned about it. They just shrugged their shoulders saying it's not their fault.
I said I'll take off the throttle body MYSELF and clean it properly,,and hopefully fix that fast idle valve.
They offered that once I fix it they will set the base idle for free.:eek2:
Then they promptly charged me $65.

Well at least I know now what wires to bridge to set the base idle I might just do it myself.:tired:

We learn how to service our cars and fix problems by trial and error. Mechanics do it the same way. The only difference is they charge you for it. lol

You paid the bill, so there's no reason not to name the mechanical group and Suburb, as it could prevent another member going through the same.

I wonder if when they sprayed that cleaner in the throttle body if they plugged the ISC air ports so it did not stuff it. I belive there's a warning about that in the manuals.

3. Plug the bypass passage inlet (arrow) of the throttle body.
Caution
Do not allow cleaning solvent to enter the bypass
passage.

You paid the bill, so there's no reason not to name the mechanical group and Suburb, as it could prevent another member going through the same.[/QUOTE


Hi thanks for our reply, the only reason I don't want to name the company is for legal reasons. I think you can still get in the shit if you slander a company's name even if it is true. They can claim they have lost Business because of what you said. They also told me on the phone they charge $110 per hour and it would only take half an hour and would be $55. I ouoted this when they stiffed me for the $65,, but they claimed they worked for an hour and was doing me a favour by charging me only $65. I came back with you did 30 mins work and 15 mins of trying to work out what went wrong. My daughters car came out worse than when it went in[QUOTE=Ozzcaddy;1354153]

Like I said, some mechanics experiment on your car as a learning experience, and expect you to pay for it. Maybe you could say up front something like "Don't expect any money if you can't fix it." lol

Well if they're a Nationwide "reputable " Group try sending a written complaint to their Head Office if you believe thay have not done the right thing. To me it sounds like the ISC might be jammed alowing too much air to bypass the throttle body.

Assuming all they did with the ECU is open the case and inspect for possible leaking capacitors and did not play with it and as far as I know there's nothing adjustable in there anyway, there's no logical reason why the car should not be idling somewhere around where it was.

A little higher maybe but not what you are saying. If solvents have affected the ISC I would expect that would be evident upon removal and inspection.

Or you might be really unlucky and something else has failed but I doubt it.

Sounds like they did not know what they were doing and I bet they're franchises. Why you'd remove an ECU as a first course of action has me beat, are they electronic technicians too ?.

You might find after time the ecu will correct the idle. I'd put the idle screw back where it was (should be marked) and leave it for a couple of days. Also check the throttle movement is free and comes to it's stop position instantly. If not, clean and lube.

Like I said, some mechanics experiment on your car as a learning experience, and expect you to pay for it. Maybe you could say up front something like "Don't expect any money if you can't fix it." lol
I think I should find a good mechanical shop and stick with them. I do have one but he is more for brakes and suspension and some other stuff, but he didn't want to play with the idle settings on the magna. I have let him do work on our VT and it has all been good, and at a fair price. I never expect people to do good work for peanuts.

You might find after time the ecu will correct the idle. I'd put the idle screw back where it was (should be marked) and leave it for a couple of days. Also check the throttle movement is free and comes to it's stop position instantly. If not, clean and lube.

Thanks for your reply, but I don't think the ECU is going to be able to adjust the idle as it is currently running on the fast idle valve, which seems stuck open.. If i turn the idle screw back to where it was it will be idling heaps high. They had disabled the ISC and were trying to set the base idle but couldn't get it any where near it. This weekend I will be pulling off the throttle body and pulling it to bits and will hopefully see what is wrong.

What about (1) disconnecting the battery so to reset the ECU, (2) resetting the idle screw to where it should be, (3) reconnect battery and start it up, and turn on the various accessories one at a time with about a couple of minutes in between each accessory (headlights, fan, A/C, Neutral to Drive if auto) , so the ECU can re-learn itself.

What about (1) disconnecting the battery so to reset the ECU, (2) resetting the idle screw to where it should be, (3) reconnect battery and start it up, and turn on the various accessories one at a time with about a couple of minutes in between each accessory (headlights, fan, A/C, Neutral to Drive if auto) , so the ECU can re-learn itself.
Thanks for the reply,,but they tried resetting the ECU and didn't have much luck.
It just gets me how they say its nothing they have done. Hey look I know cars are funny things,, but they just tried a few things and then just washed their hands of it. I said "Tell me was it idling like that when you drove it into the workshop"???
So now I've paid you $65 for my car to come out of you workshop worse than it has gone in

Well if they're a Nationwide "reputable " Group try sending a written complaint to their Head Office if you believe thay have not done the right thing. To me it sounds like the ISC might be jammed alowing too much air to bypass the throttle body.

Assuming all they did with the ECU is open the case and inspect for possible leaking capacitors and did not play with it and as far as I know there's nothing adjustable in there anyway, there's no logical reason why the car should not be idling somewhere around where it was.

A little higher maybe but not what you are saying. If solvents have affected the ISC I would expect that would be evident upon removal and inspection.

Or you might be really unlucky and something else has failed but I doubt it.

Sounds like they did not know what they were doing and I bet they're franchises. Why you'd remove an ECU as a first course of action has me beat, are they electronic technicians too ?.
Thanks for the reply, I have a spare ISC I could try swapping it.
With this Magna it was dropping about 300 rpm when you put it in gear it was still idling ok as I set the Park idle at about 1000rpm. Now I'm just fussy I should have left it. This car was brought for daughter on her Learners.
Anyway they claimed that it is common for the ECU to stuff up and do this ( The ISC is OK ) They SAID they can tell just by looking at it. WELL they looked at it and didn't know, So they just put it back
This company is Australia wide I might write a complaint letter to their head office,,,,,,,but they may just chuck it in the bin.
They are a franchised

i never know taking a visual look at a ECU to be a proper diagnostic method, but i dont have 20years in the trade, are you sure they just looked at it or did they actually test it?

Thanks for the reply, I have a spare ISC I could try swapping it.
With this Magna it was dropping about 300 rpm when you put it in gear it was still idling ok as I set the Park idle at about 1000rpm. Now I'm just fussy I should have left it. This car was brought for daughter on her Learners.
Anyway they claimed that it is common for the ECU to stuff up and do this ( The ISC is OK ) They SAID they can tell just by looking at it. WELL they looked at it and didn't know, So they just put it back
This company is Australia wide I might write a complaint letter to their head office,,,,,,,but they may just chuck it in the bin.
They are a franchised

Dropping by 300rpm sounds like the isc is not compensating enough. I don't know if you need to dismantle the throttle body though. I'd focus on the isc first which is removeable without dismantling the TB. The manuals have some basic resistance checks you could do for the ISC windings, how sure are you that it is still functional? I'm just suspiscous about it if the only 2 things they touched were the ECU and the ISC/TB clean. Now that idle screw has been adjusted the ECU is going to try and use the ISC to return the engine back to its correct speed within the adjustable range of the ISC.
Now assuming that the throttle stop screw has not been messed with, the TB is clean, the TPS in set correctly and I think you said it was idling too high even with the idle adjustment screw all the way in then that suggests to me that too much air is being bypassed through those ports in front of the butterfly.

,
Send a letter anyway, you may even get your money refunded at least you could use that to put towards getting someone to diagnose your problem correctly. Don't just cop it, there's a lot of average service around.

My philosophy is nothing will change unless you make noise about it. Likewise if find someone really reputable and good spread the news. Just an opinion.

Hi well I pulled the throttle body to bits and cleaned it. When doing this I checked the butterfly and I could see it wasn't fully closed.
It must have been that when it had lots of build out around it it was making it seal,,but when they cleaned it they cleared all of the build up away.
I readjusted it and put it all back all is good now.
Hope that makes sense
ISC test is good with meter