93 Legend has high idle in park and neutral

jlandry · Newbie Joined: Jan 19, 2004 Posts: 4

When I put my 93 Acura legend in neutral or park the rpms rev up to 1300rmps and bounces between 1300 and 900 rpm. When i put the car in drive and have the brake on, it revs a 750rmp like it is supposed to. What could be causing this problem? Also when i first crank the car in the morning a lot of white smoke or should I say thick exhaust comes out the tail pipe and it smells like exhaust not smoke. What could be causing that? I am baffled at both these problems.

AcuraImport · Site Admin Joined: Mar 11, 2003 Posts: 227

Hi Jlandry,
The problem with the wierd idling is caused by two things your MAP sensor has gone bad, or you might have a short in ECM. Is your check engine light on?
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If you feel like you're in control, you're not going fast enough. - Mario Andretti

jlandry · Newbie Joined: Jan 19, 2004 Posts: 4

There is no check engine light on. I think the MAP sensor is my problem. I had my car worked on a few weeks ago becuase it was smoking and they put new valve seats in. This stoped the smoking but now I have this idle problem. What is the ECM.

AcuraImport · Site Admin Joined: Mar 11, 2003 Posts: 227

ECM stands for Engine Control Module. The engine control module (ECM) is connected to several sensors and sending units on the engine and then automatically calculates the optimum amount of fuel to be injected into the combustion chamber. The benefit is smoother and faster acceleration, crisp throttle response, maximum fuel economy thus ensures quick and reliable starting.

It also monitors to make sure that there are no problems with your sensors or other engine components. When there is a problem it will store and then send you a Diagnostic Trouble Code (DTC). The code will give you an idea of what has failed and needs to be fixed. That is when your 'check engine' light comes on.

However if its an intermitent problem a DTC is not always recorded. My MAP sensor was going bad for a little while before my check engine light came on. It is a fairly common problem with Honda/Acura engines.
_________________
If you feel like you're in control, you're not going fast enough. - Mario Andretti

jlandry · Newbie Joined: Jan 19, 2004 Posts: 4

I am also getting horrible gas milage. I get about 150 miles to a tank of gas. Is this also caused by the MAP sensor.

AcuraImport · Site Admin Joined: Mar 11, 2003 Posts: 227

Its possible that your MAP sensor is causing your mileage problem, however it could be something else. there isn't anyway to be certain. Just take it one step at a time. Deal with your idle problem/MAP sensor and see how your gas mileage does after that is fixed.
_________________
If you feel like you're in control, you're not going fast enough. - Mario Andretti