backdoc

Hey paul,
So I did what you told me to do. With the power output stages as is, i got to the measuring blocks channel 19 and 20. started the car and got misfires on cylinder 2. At one point the misfires/1000rev went up to 26 but mostly stayed around 5. Shut off the car and swapped the power output stages plugs. There were 4 plugs in total, two on the top of the bracket and two on the bottom. I took the bottom ones and put them on the top connectors, and the top plugs on the bottom connectors. I assume that's what you ment.
Got back into the measuring blocks and started the car up. Misfires again in the #2 cylinder. Now what? One thing of note, I cleared the codes and started the car and it seemed to idle ok and the check engine light did not come on. Went for a drive and it was still rough at low RPM's. The check engine light came on a mile down the road. It almost seems like it's a little better, but I still have problems. Let me know what I should do?
Thanks!
Doug G.
97 A8 4.2

PaulW

Do you have the Bently?

Your power output stages are good, you could have a bad signal from the ECU to the power output stage, but I'm going to say that's not likely right now.

So first things first.....check the resistance of the fuel injector. Go to cylinder number 2 (should be shown once you take the beauty covers off) and pull the injector wire connector.

On the injector itself, using a multimeter selected to OHMS, in the lowest range. Go across the two terminals on the injector and measure the resistance. It's best to do this with a digital multimeter.

If you don't have one and want to buy another tool, get one, but make sure you get an auto ranging multimeter (digital, of course), should be around $40-$100. If you want a real nice one, get a $99 Fluke model at Sears. It's super simple to use and the very highest quality.

A $40 auto ranging one from Pep Boys or Radio Shack will work too. Don't get a $30 one.

The resistance of the injector should be 12-20 ohms. If it is out of this range (probably will be open circuited, very high resistance) then it needs to be replaced.

If it's in this resistance range, it's most likely good. I'm thinking it is mechanically clogged. That is what has happened to a bunch of us.

If it's good, then I would get the o-rings for the injector from the dealer, pull it and inspect it.

Put some more Techron in the tank too.

pw

backdoc

yes I do have the Bentley, but I find their explanation of procedures is more complicated than it needs to be sometimes. I will check the resistance across the fuel injector plug and report back. I have also put another bottle of Techron in it. Thanks.
Doug G.