Defender

I am trying to recall the correct start-up sequence because I think it may have some relation to my cars woes.

I seem to recall that when the engine is first started that in addition to the engine running that something else would run as well (the air pump ? the a/c compressor ?) and that the additional thing (whatever it was) would run for about 20 seconds or so with a fast idle, and that then the additional thing would stop running and the idle would decrease suddenly to normal idle speed.

So the question is ... does my recollection have any basis in reality ? Does this happen ? And if it does happen ... what is the additional thing that runs upon initial start-up.

When my car starts it just starts ... and the engine runs ... there is no additional thing running and the car does not idle above normal at all upon start-up.

Thanks in advance.

Eliot

Squeezer

yes thats the secondary air pump that makes that whine when you first start your car. i think it lasts for 60 seconds, not 20. your idle speed should not suddenly decrease from the warm up of 1500 rpm to the warm idle of 800. as your engine warms up over a period of several minutes it should gradually decrease from 1500 to 800 and you'll be at 800 with 3 bars on the temp guage.

if you aren't hearing the secondary air pump whine, your car should be throwing the check engine light. also the engine not going to 1500 rpm on initial start when cold (sitting for several hours) means something is wrong. I'd guess the coolant temperature sensor is malfuntioning and reading that your engine is always hot.

Defender

Thanks ... I have not heard the secondary air pump in a long time. Which coolant temp sensor would that be (I know there is a tempertaure sensor in the rear left side of the engine ... is that it ?) ?

xviper

The airpump is located in the left front cavity, just behind the fake airduct. If you suspect it's not working, the next time you do a cold start, immediately go out and put your ear down near the corner of the bumper. You should hear it going. If you can't tell if it's the airpump or some other engine noise, just stay there for a minute or two. It'll stop if it was running.
Also, upon keying the ignition to ON, you should hear the fuel pump in the gas tank whine mometarily as it pressurizes up the system. This should only be a couple of seconds.
Of course, if you have the interior fan on, it will come on as well. Turn all your interior devices off so you can hear the airpump and fuel pump better. I'm talking about the interior fan switch and radio.

Defender

I just took off the plug to the map sensor, took out the three crimped connectors from inside the plug, recrimped them a little tighter, put the plug back together, reinstalled the plug, and started the car. It went to high idle (2000 rpms) at first but I did not hear the air pump running (I was inside the car). FYI -- it has not gone to high idle at start-up for some period of time now, so this is something different. I will try it later , get out of the car, and put garden hose down in that area to listen better for it.

xviper

How hot has it been in your location lately? If it's very hot where your car is parked, a "cold start" may not trip the high idle sequence and the airpump may only run for a very short time.
But like already stated, the ECU does a self check on the airpump. If it's not well, you'd get a CEL.

Defender

ok -- I heard it ... the car still runs like sh_ t, but I heard the air pump . It ran very very briefly ... yes it is hot here. Thanks !!