Reinman

How do you test a coil? My car still don't start, I think it may be a coil on the passenger side (where the hall sensor is too). Would a failed coil yield no needle bounce on the rpm dial? (We certainly wouldn't have enough spark to start the car, especially SINCE THE NUMBER 1 CYLINDER is on the passenger bank of cylinders.

Just trying to eliminate all possible angles before we dig deeper.

Thank you!

Rein

audiqv8

A bad coil will not affect the tach needle bounce. A bad speed sensor or bad ECU will affect the tach needle bounce. Is there a spark?

Reinman

We will test for spark tomorrow. We replaced both sensors with new, and tested before install. no bounce on rpm dial. Worked one day, dead the next am, started once, ran on about 4-5 cylinders, then haven't been able to start since.

Spark check tomorrow. flywheel pin check was recommended too (after starter pull - although I would probably leave starter in and remove sensors, and view for pin through driver wheel-well and sensor plate (once sensors vacated).

Rein

toml99

http://s217.photobucket.com/albums/c...h_photos/Audi/

Never had a coil go bad on the V8's, but here you go....

toml99

Oops...heres the link....Tom

http://i217.photobucket.com/albums/c...nitioncoil.jpg

Reinman

I tested the coils at the prescribed contact point 1 and 4 atop each coil.

-The drivers side read 7.23 (multimeter's OHM set to 20K 7.23 = 7230)

-The passenger side read 0

I tested the coil wires of both sides.

-The driver side read resistance 2.0 (multimeter's OHM set to 20K 2.0 = 2000)

-The passenger side read resistance 0

I replaced the passenger side coil wire.

-Both sides show spark output.

Passenger side coil terminals 1 and 4 still read 0 (weird) but still spark. Why?

I now have slight RPM needle fluctuation under the 400 RPM slash mark, and the motor seems to turn over more smoothly than before. BUT STILL NO START.

Rein

Prospeeder

So you have spark right? you have tried some carb clean in the intake while cranking? If it has spark, and it has fuel, then its not happening at the right time. ECU, signal from Crank sensor to ECU and cam timing really are it there.

Reinman

I did not know whether it is safe in this fuel injection type to spray carb cleaner in to see if it is a fuel pump issue or not. That will be next. Then we will go to ECU. I put two new sensors in. I hope it is a fuel pump as I have a new one in stock and the tool to change it out if need be.

I am curious as to why the terminal 1 and 4 test of OHM nets a zero though? That tells me something is not going somewhere? we have spark, but no OHM resistance reading on the passenger coil test. ???

Thanks

toml99

I got stranded 40 miles out a gravel road in ID running out of daylight in my first V8 years ago with a failing speed sensor. I'd done some epoxy work out there, and had a quart of Acetone in the trunk. I soaked a sock in acetone, and stuffed it into one of the intake bellows, and it sparked up. I changed the speed sensor when I got home, and has run ever since.
Secondary resistance test states that if you are getting anything other than 5000-9000 Ohms, then "Replace ignition coil".....Think I'd start there. Tom

Reinman

This has been the most frustrating "Audi Delay" of my time between two V8 cars and 8 years.

Tom: Why can I have spark at the coil, but between terminal 1 and 4 no ohm reading? You'd think with spark the car would start...if not, then it would be sensors (but I put two new ones in "pre-tested"), or a fuel pump (a no fuel issue).

Today, I cranked it and cranked it and cranked it and it was sounding like it wanted to start but nothing.

I sprayed carb cleaner into the back of the open end of the manifold facing the firewall, but nothing (although I didn't douse it either). I also ran the codes again and got 4444 and 1111 that's it.

Could it be the fuel pump relay, and is there a way to override that to test and rule that out? That relay looks as if it has a built in over-ride or a fuse port on it. ???