86 Cavalier High idle

In article , Robert Hancock
wrote:

 > Could be a number of things - bad coolant or intake air temp sensor, vacuum
 > leak, problem with the idle air control valve..

Forgot to mention that the idle air was replaced too. I have no clue
where the intake air temp sensor is. I looked on the intake manifold
and didn't see anything that looked like a sensor. Looking in the wrong
place or just over looking?
Thanks for your reply.
 >> Stay informed about: 86 Cavalier High idle 

My guess would be it's in the intake air ducting to the air filter..

--
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"HighnMighty" wrote in message



 >
  > > Could be a number of things - bad coolant or intake air temp sensor,
vacuum
  > > leak, problem with the idle air control valve..
 >
 > Forgot to mention that the idle air was replaced too. I have no clue
 > where the intake air temp sensor is. I looked on the intake manifold
 > and didn't see anything that looked like a sensor. Looking in the wrong
 > place or just over looking?
 > Thanks for your reply.
 >
 >> Stay informed about: 86 Cavalier High idle 

In article , Robert Hancock
wrote:

 > My guess would be it's in the intake air ducting to the air filter..

The intake air ducting is just a plastic tube with nothing inside. The
air filter sets on top of the throttle body. Wait..... there is a
vacuum thing on the metal part of the air intake (for cold starts).

Well, we just started taking off the temp. plugs one at a time. When
the one for the computer (I think) was unplugged the engine idled down
.. It was erratic and was puffing black smoke. When you plug it back in
it starts idling high again. You think that sensor was the problem or
would it do that anyway?
 >> Stay informed about: 86 Cavalier High idle 

"HighnMighty" wrote in message

 > Hello, I have an '86 Cavalier with a 2.0. It idles high when started
 > and doesn't idle down. It seems to idle even faster when it's warmed
 > up. We've changed the computer and throttle position sensor. Still no
 > luck.I thought it might be a vacuum leak somewhere or a bad sensor that
 > we haven't checked or replaced yet. Any ideas?
 >
 > TIA!
 >

The TBI unit is probably carboned up, blocking off the vaccume ports.
Easy way to check is to pull the lines and check for vaccume. Then if you
have vaccume trace each line down, looking for cracks, or splits.

If the problem was the same before and after TPS & IAC replacement, you
could very well have wires that are dropping voltage. Cracked or worn
insulation, broken strands, ect.
Charles
 >> Stay informed about: 86 Cavalier High idle 

"HighnMighty" wrote in message



 >
  > > My guess would be it's in the intake air ducting to the air filter..
 >
 > The intake air ducting is just a plastic tube with nothing inside. The
 > air filter sets on top of the throttle body. Wait..... there is a
 > vacuum thing on the metal part of the air intake (for cold starts).
 >
 > Well, we just started taking off the temp. plugs one at a time. When
 > the one for the computer (I think) was unplugged the engine idled down
 > . It was erratic and was puffing black smoke. When you plug it back in
 > it starts idling high again. You think that sensor was the problem or
 > would it do that anyway?
 >

The Coolant Tempiture sensor/sending unit is on the bell housing side
of the cylinder head, by the thermostat housing.

On the intake there should be the EST (Electric Spark Timing sensor) &
the PULSAIR controller. Which has to do with the Smog Pump if so equipied.

If you unplugged the spark timing sensor, the engine shopuld run rich as
timing is retarded.
Charles
 >> Stay informed about: 86 Cavalier High idle 

Hello there,

I have a 1994 GM Oldsmobile Delta 88 with the same problem. I've also
changed the Throttle Position Sensor but have had no luck in solving the
problem.

I have found though that when the engine is idling at 2000 rpm +, if I pull
off to the side of the road and turn off the car and then restart the car,
that the car will idle at 800 rpm for the remainder of my trip.

If you have found an answer for this problem, I'd really appreciate hearing
about it.

--jc


"HighnMighty" wrote in message

> Hello, I have an '86 Cavalier with a 2.0. It idles high when started
> and doesn't idle down. It seems to idle even faster when it's warmed
> up. We've changed the computer and throttle position sensor. Still no
> luck.I thought it might be a vacuum leak somewhere or a bad sensor that
> we haven't checked or replaced yet. Any ideas?
>
> TIA!
>
 >> Stay informed about: 86 Cavalier High idle