mazdaspeed7

I have had a high idle(~1500 rpm!!!) on my car for months and months. Nothing I have found yet has helped it. Had the intake manifold off 3 times hunting for vacuum leaks, and trust me, there are NONE. I replaced the clutch switch that affects the idle, still didnt fix it. BAC is disconnected, no change. My car has no emissions stuff, and therefore no vacuum lines, except the FPR. The throttle stops are all the way up, I sealed the hole in the main throttle plate, and the idle adjustment valve on top of the tB is all the way down, but the idle STILL wont drop below 1500. Sometimes the RPM's will drop below that, and the car will stall. It seems like the ECU is making my car idle high.

The other day my mechanic friend mentioned something about the nuetral switch making the car idle high when the car is in nuetral. I suspect this switch may be bad, b/c the idle does not change a bit between nuetral and in gear, with the clutch in, even though it should if the nuetral switch is good.

My question is what would happen if I bypass that switch? Unplugging it(never any continuity) would make the ECU thnk the car is constantly in gear, which, if I am reasoning correctly from what I was told, would make my idle normal. If it was constantly open(which I believe it is), would my idle not always be high then?

mazdaspeed7

bump

mazdaspeed7

FIXED!!!!!

It was a bad nuetral switch and bad clutch switch. I think the signals were conflicting(when both switches were bad) which was confusing the ECU a lot, and really screwing over my idle.

live4boost

iTrader: (2)

did you just take the switch out and directly connect the wires? Or did you just buy new switches?

mazdaspeed7

I had a good clutch switch on my parts car, so I used that and simply unplugged the nuetral switch. It makes the ECU think the car is always in gear. I have an extra nuetral switch I might put on later.

live4boost

iTrader: (2)

my clutch switch is bad, but I think that Ill just bypass it.

kleach18

where are the two switches

live4boost

iTrader: (2)

clutch switch is under the dash on the drivers side above the clutch peddle. I don't remember where the nuetral SS is.

pp13bnos

iTrader: (1)

so whats it idle at now? CJ (just curiosu)

mazdaspeed7

It was very very cold today, and I didnt have time to mess with the idle setting and TPS, but right now, it hunts between 900 and 1200, but very very slowly, a few seconds per cycle at least.

The nuetral switch is on the tranny.

kleach18

how do you know that the clutch is bad is there a way to test it

kleach18

can anybody help??????

mazdaspeed7

I checked for continuity with a volt meter when the switch was opoen and closed. It didnt change, so the switch was dead.

mazdaspeed7

Theres where the nuetral switch is.

Anyone else think this should be archived?

Erik

I do I do

mazdaspeed7

bump

kleach18

would i be able to see that from under the car or is it on top of the trans? i can't tell from the pic

mazdaspeed7

Its on the pass side, at the top of the vertical part. It is easy to get to from under the car. Ill take a pic of the tranny in the car next time I have my car on jack stands.

kleach18

ok so how would i test that to see if its bad? Volt Meter or what and what readings should it have?

kleach18

what would this cause the car to stall? only when its not in gear.

RotorBalls

iTrader: (1)

Very good info here I give it a

mazdaspeed7

I checked for continuity when the car was in nuetral and in gear. If it changes, then the switch is good. Sorry, but I dont remember whether its open or closed in nuetral.

It caused the high idle in my car. No matter what I did, I could not adjust the idle down from 1500 rpm. It always seemed like the ECU was not letting my engine idle below that.