93 Loyale Pulsing Idle

[JWD06OBXT]

I'm having an idle issue that arises every so often seems to happen at random and can't seem to pin point what may be causing it. After intermitant driving and coming to a stop the idle pulsed between 1300rpms-1000rpms. Any ideas of where to start would be appreciated. This is my first EA and not super familiar with its in's and out's yet. So far it has been a great daily driver after fixing a leaky valve cover gasket. Car has about 179K on the odometer. Photo below. 

 

 

 

Edited November 2, 2016 by JWD06OBXT

[MR_Loyale]

Whenever I have seen that, it is my IAC acting up. A cap of Berrymans (just pop off the hose to access valve), let sit 5 mins and start. I do this as annual maintenance and never had the issue again.

[DeltaWye]

Our 94 Loyale started idling funny last year.  Eventually the 'check engine' light came on and the code indicated a problem with the coolant temperature sensor.  It's right near the thermostat.  You can unplug it and check the resistance with a multimeter, I don't have the Hanes book handy but I can look up the correct value.  Ours was way off and replacing the sensor fixed the problem.

 

Make sure you get the right sensor if you're ordering it online, there's a similar one that goes into the radiator that turns on the electric fan if the coolant in the radiator gets hot enough.

Edited November 17, 2016 by DeltaWye

[DaveT]

Check the CTS.  IT can get intermittent and not trigger a code.  IAC valve can cause similar.  Intermittent wire / contact to either.  CTS has 2 wires, and is screwed into the manifold thermostat housing.