1998 SL2 idle problems after Starter replacement

Ok, to be as precise as possible, Im going to list the entire chain of
events in detail, so get ready, this is a little long...

March 16th - I had my starter replaced with a remanufactured starter
at a local Pep Boys after having to push-start it a few times
recently. I knew it was going bad, so it wasn't a surprise.

March 16th-March 18th - Normal driving to and from work, no problems
except that when I started the car in the mornings (im in the
Northeast, so its cold), the RPMs would shoot up to about 2300 or so
for about 3 or 4 seconds, then settle down to normal idle.

March 19th - I made a 2 hour drive to an airport, where I left the car
parked for 5 days. Nothing out of the ordinary.

March 24th - I drive back from the airport, turn the car off to get my
mail, and when I turn the car back on the starter motor continues to
turn. I turn the car off and take out the keys, and the starter is
still turning (or at least I believe it was the starter). I open the
hood and realize I dont have any tools to disconnect the battery
without getting shocked, and when I touch a metal part of the car, I
get a small static shock. Luckily, after about 5 minutes, it stops.

March 25th - I take the car back to Pep Boys, and they replace it with
another remanufactured starter and Im on my way. Heres where the
problem starts.

As soon as I get the car back from Pep Boys, I start the car and the
RPMs shoot up again like they did in the cold. They eventually settle
down, so I start driving out. Once I do, I notice that every time I
push in the clutch to change gears (manual trans), the engine will
jump about 200-300 rpms while the clutch is disengaged, making it kind
of odd to re-engage. This behavior occurs in all 5 gears.
Also, whenever I switch into Neutral to coast to a stop, the RPMs will
go to 2000 and stay there until I come to a COMPLETE stop. It doesnt
matter if I slow down quickly or slowly, the engine stays at 2000RPMs
until the car has COMPLETELY stopped. Once Im stopped, the engine
settles around 1100-1200RPMs, typically.

I called Pep Boys and told them about this, and they said that it
"sounds like a voltage problem." Im an engineer, and I realize that
this is likely just blabber coming forth from the technicians mouth.

I dont know if the problem was due to the installation of the new
starter, or if another part, specifically the Idle Air Control Valve
(IAC), was accidentally damaged during the installation of the
starter. Or it could be something else entirely, all I know is that
it only appeared after the starter was installed.


Anyone have any ideas as to what this might be?

 

The vehicle speed switch is the reason that the rpm's stay high while the
car is still moving. Once the car is stopped, speed sensor is not giving any
output and engine managment shifts to another control parameter.

Did you get the codes read out or check with a scanner? The Coolant
temperature sensor or Induction Temperature sensor might be giving bad
outputs and would account for high idle. Also check for any loose vacuum
hosed or broken vacuum fittings. You always have to wonder when a mechanical
component is replaced - especially if it is hard to get at, what was
disconnected, broken or moved when trying to gain access to the area.

Oppie (also an engineer)

 

Yeah after doing some research ive got an idea that some hoses on the
Carbon Canister Purge Solenoid (CCPS) might have been disconnected. I
wont have time to look at it until this weekend, but ill let you know.

Could there be something wrong with the speed switch you mentioned?

The Service Engine Soon light is NOT on, so im assuming there are no
error codes stored in the PCM. Or is that incorrect?

 

Odd that the SES light is not on. Sounds like a vacuum leak that would do
this. If the CTS is bad, it would indicate a cold condition which revs the
engine and enriches the fuel mixture. Most of the codes are not actually
logged until the engine is at operating temperature... which sounds a
plausible explanation.
Speed sensor is only an electronic speedometer. Not to worry about this in
your case. It seems to be doing its job.
Oppie

 

neither the idle speed sendsor or the temp sensor will through a code.
Vacumn line would be best bet though then from a cost standpoint the
temp sensor follow by the idle sensor.