Does this sound like the alternator? FIXED!!!!!

Post by **NafemanNathan** » Mon Oct 12, 2015 10:37 pm

Multimeter on the battery terminals bud.

Post by **NafemanNathan** » Tue Oct 27, 2015 10:52 pm

So to continue this, I've replaced the alternator with a known good one (courtesy of Phil. Thanks Phil

), but it's made no difference, the revs are still dropping right down to under 500rpm and almost stalling when braking.

I've also noticed now that the biggest draw on the revs is when I turn the steering wheel.

Any other ideas? I've got a few more things to try, but it'd be good to hear your thoughts.

Post by **ek9sid** » Wed Oct 28, 2015 6:12 am

Pas pump?

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Oct 28, 2015 6:58 am

It's normal that using the power steering will load up the engine and cause the revs to drop momentarily. What should happen is the ecu should see that and counter act it.
Don't know what the A7 has by way of idle control hardware, so no idea where to go from here, though...
Does it still have an iacv like an a? Have you tested that properly?

Post by **Donald** » Wed Oct 28, 2015 8:13 am

Have you tried swapping the engine?

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Oct 28, 2015 8:39 am

Post by **NafemanNathan** » Wed Oct 28, 2015 9:02 am

Swapping the engine was obviously the first thing I tried... Made no difference.

No, the PAS is definitely drawing more than it should, but as this is not alternator powered, yet alternator powered items are also having the same effect, it's making me think it's a "compensating" sensor that's at fault/not cutting it. Make sense?

Next up is to try the MAP sensor.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Oct 28, 2015 11:45 am

NafemanNathan wrote:it's making me think it's a "compensating" sensor that's at fault/not cutting it. Make sense?

Yep, that's what I meant - either the ECU isn't seeing the revs drop adequately, or is not able to act on it properly (by whatever equipment it uses to compensate and increase engine revs/power).

Post by **NafemanNathan** » Wed Oct 28, 2015 12:47 pm

Oh and to answer your IACV question, it's running a Prelude iacv that I installed before Rich tuned the car. This issue is something that has developed long since then. I'll swap out the MAP sensor and see what happens. Got two others to choose from

mercutio · Post by **mercutio** » Wed Oct 28, 2015 6:37 pm

i just bought a 100amp alternator

worked fine then

Q the known good one was it charging ? but not turning off the light