Throttle body cleaning issues EPIC Volvo saga...RESOLVED!!

[precopster]

Hey Sergio. I'd love to see you solve this one as easily (or hard depending on how long rewiring takes) as this. Just wondering as to how this will go as you had oscillating idle BEFORE you did the PCV job. Perhaps just an unfortunate series of events such as:

1) Failed MAF or ETA

2) Clean the PCV and create a short

3) Replace the above then never really adapt the new throttle because it had no voltage supply

Here's a toast to your rewiring project

I'd be VERY careful about charging with ignition in Pos II. Home grade chargers usually don't produce particularly clean power and often have AC at very high levels. I NEVER charge a battery while it's fitted in the car due to this.

Computer modules are too expensive to risk.

[sergio]

Continuity re confirmed
Short ( you told me so ) not detected.

Back to square on

[precopster]

It was worth a try

I wonder if your MAF also has incorrect supply. Time to check supply volts at ECM connector (did Draser do this with ECM disconnected?)

[sergio]

This is crazy...

1st
Further testing of MAF confirms that continuity. BUT there seems to be NO voltage at any of MAF connector!
MAF is connected to ECU but no juice is coming from ECU to MAF.


2nd
I left the battery charger connected and plugged on maintenance mode (I think 2 Amps).
I turn the key to position 2 the sound of the fan of the charger changes almost immediately.
Voltage drops to 10 V. I turn the key to 0 that sound changes in 2 second.
I mean I have the battery AND the charger both supplying juice and I get 10V.



.

[precopster]

It is sounding more and more like the ECM is at fault here.

Just an idea..... Buy a cheap guaranteed ECM from eBay and plug it in. Even though it won't start your car it should have volts at crucial test points such as MAF and ETA. The unmatched ECM will tell the immobiliser not to start the car.

Then send them both to Lucky from ARD and he will program match the new one to start your car

I'm not a fan of allowing battety chargers near a car's electrical system. Please promise me if you get a new/used ECM you'll remove the battery from the circuit (by disconnecting negative lead) before you charge the battery. Did you read my 2nd last post about chargers?

[sergio]

.

__ Buying parts has been a practice that until now has never, never, I mean never been good for me. From the first crankshaft sensor 3 years ago (to find out that the burnt wire of the fuel sensor was the reason the car wouldn't start) to MAF and ETA of last month $$$. Could have paid that money to a professional to have the job done.
I will rather send the ECM to be tested.


__ The battery, it is less than 3 years old under exchange warranty. I will try it tomorrow.


__ If push comes to shove, I will open the ECU to sniff the guts. Hell, maybe the contact cleaner left from cleaning the connectors gives a better result here


__ Regarding charger + battery to crank the engine, I had to do something, otherwise I don't make a habit of this practice, specially after having read your advice .


If by October the car is not fixed, I will sell it piece by piece.


.

[draser]

Just to be on the same page, you tested with black/negative lead connected to ground/chassis, and positive/red lead on each pin of the connector, meter set on volts continuous? If that's true then you've found your problem.
However, in order to get 12V to MAF and ETA, the ECM needs to get it first. So can you make sure that you find 12V on ECM as discussed before? You will not be able to measure on ECM directly, rather check voltage on fuses on top left of the diagram.
Fuse 11B/6 and relay 2/32 are in engine bay fuse box. Pull the relay and look at the contacts to be clean, have someone put key in pos 2 and make sure relay clicks. You should have 12V on the fuse if relay works. You can have the lead connected to the fuse via a short piece of wire (pull the fuse, stick a thin wire in one contact and put fuse back in) and tap the relay to make sure voltage is steady.

[sergio]

.

Thanks draser
[One of] My problems is that so far I have not been able to maintain 12V for more than few seconds after the key is set to position 2.
Even with the charger (output 13.45V) piggy backing a fully charged (12.7V) battery, as soon as the key is turned to position 2 the voltage, measured at the battery level or engine side, goes to 10.1 and stays there until key goes to position 0, then it starts inching up; 1/10 of a V each few seconds!

The last battery I had would get charged to 12V but after couple of extra cranks would go to almost 0.
This one goes to 10.
Anyways, tomorrow I will try to use my right to an exchange


.

[abscate]

Could have paid that money to a professional to have the job done

At least you didn't pay someone 100 USD an hour to do exactly as you have done, and many mechanics will end up doing exactly that.

[sergio]

.

Could have paid that money to a professional to have the job done

At least you didn't pay someone 100 USD an hour to do exactly as you have done, and many mechanics will end up doing exactly that.

Can I quote you to my wife who is convinced I am the reincarnation of Ralph Kramden


.