Starting my Knock Sensor replacement today......

[elwesso]

Heck, I backed out the IAC screw about 3 1/2 turns to set the ldle higher, and went around the block for a "testdrive". The stumble is gone, she shifts smooth, I'm sure the tires have flat spots (from sittin) causing a funny ride.

Now Im gonna try to pull the idle down...I'll check and see how many turns I get going "in". Shouldn't it be about 3-5 turns out?

Whats a quick way to "clear the codes"? Last night I had the MAF unplugged and forgot so when I raised the windows, I started the car up, now I have codes 12 and 21...

I'm feeling alot better after the "testdrive"...But I need to clear that dang ECU....

Yeah you definitely have to drive the car for a while (including a few redlines) before you can tweak things...

The IAC should be backed out 1.5-2 turns.

[Meaux]

Heck, everytime I get the idle set at about 650+, the car won't keep running after startup...When I start it, it dies as if it's not getting gas, if I pat the pedal it'll keep running...then start hunting for a spell, then settle down...If I raise the iddle spped up to 900rpm, it will keep running after startup...something wierd is still wrong because it dosen't compensate for A/C load...With the A/C on, in drive, 500rpm, can't even feel it running...

[PoorManQ45]

um, maybe that's because it's not supposed to idle(in park or neutral) at 650rpms. I set mine between 800-900rpms and it idles much better. Now, when I shift from park to drive the rpms drop down to about 600, but it runs smooth.

[DAEDALUS]

Spark plugs don't get dielectric grease. Assume you meant the harness plugs (connectors). Does the AC still work? Make sure the IAC harness is connected. Sounds like a crazy vacuum leak if not the MAF.

[Meaux]

LOL, no grease on the plugs...

A/C works fine, IAC harness connected.

How the heck does one clear the codes on the ECU?

I going blind trying to find that out....

[DAEDALUS]

zerothread?id=27012

[DAEDALUS]

Can you unplug the ECU connector and the IAC connector, and see if there's continuity between the 2 via the harness? You'll need a long jumper wire on the ohmmeter.

[Meaux]

Allright dangit!

I go out and turn the KEY "ON"....

Set mode switch on ECU....CW then CCW

Get codes 12, 21......

Turn Mode switch CW then CCW to clear codes....

Turn KEY "OFF".....

Wait a few seconds....

Turn Key "ON".....

Set mode swwitch on ECU....CW then CCW

Get 5 long flashes.....then 5 short flashes......

Does that mean all I have to do is set the IAC?

So, I assume there is nothing wrong with the Ignition Circuit?

I scared to touch it now....LOL!!!!!

[DAEDALUS]

Won't know until you start the car. The ECU won't know if the error is still present until you crank it over and, for some codes, until the engine has a chance to go into closed loop.

[Meaux]

When I started the car she went to 700rpm steady, backed it down the driveway and back up shut her down, re-read the codes and still get 5-5...

But, upon re-start, she started up and then died.

I jacked up the IAC to 900rpm, gonna change the oil, put all the covers back on and drive it for awhile (a few days). Then re-adjust the IAC....

I noticed that unpluggin the IAC while running, didn't change anything... maybe that thing has gone poo-poo........

Hell, at least the dang thing runs....and I didn't suck any paper towels down the intakes...:-)

[Q451990]

I noticed that unpluggin the IAC while running, didn't change anything...

The idle speed won't change (as it says it should in the service manual) when the valve is set open way above the factory setting...

Heath

[Q451990]

um, maybe that's because it's not supposed to idle(in park or neutral) at 650rpms.

You must have a different version of the service manual...

[maxnix]

You must have a different version of the service manual...

Remember, his is in that minor Klingon sub-dialect.

[RobertsnewQ]

Heck, everytime I get the idle set at about 650+, the car won't keep running after startup...When I start it, it dies as if it's not getting gas, if I pat the pedal it'll keep running...then start hunting for a spell, then settle down...If I raise the iddle spped up to 900rpm, it will keep running after startup...something wierd is still wrong because it dosen't compensate for A/C load...With the A/C on, in drive, 500rpm, can't even feel it running...

Is that cold start? Cold start is a mechanical thing. Warm start is all about the AIC. If you're disconnecting the AIC and getting the sam idle then you you need to close it up a bit, or something is definitely wrong. According to the FSM you should have 625 in neutral with the AIC disconnected and the engine warmed and 650 or so with it connected....

[slipnfall]

Wow... and I thought the knock sensor on my 240 was a PITA...

joking guys... I just can't believe this turned into a 75-post thread(+1... )

[Meaux]

Got around to take a test drive this morning. 94Q, 80K.

Started up, idle at 1200, cool.

Turn on A/C, went down the street @25mph.

Stopped, took a left onto a 55mph zone, car now felt like it was running on 4 cylinders, (vibrating like on square wheels) this continued for about a mile.

Stopped at the Bank for 10minutes, back in the car, startup fine. once back on the 55mph road, floored it @ 30mph, downshifted fine, upshifted fine till I lifted @ 90mph.

Got home, run diagnostic 2, got code 21...I guess that is because of the rough running...

Cleared the code, ran at 2000rpm...no load.

Now I get 5-5 code.

If I have a bad power transistor/coil whatever, wouldn't it stay bad?

Sounds like a bad connection to me.

Make sense? Would you just clean contacts when it cools down?

I had this rough running before I did the KS, but it only lasted about 3 minutes...and would go away for months, then come back...