1994 Non Turbo 850 - cleaned ThBody now IAC won't work

Post by **dborgers** » 08 Sep 2008, 21:56

Cleaned the Throttle Body yesterday. While I was at it I cleaned some electrical contacts (with Elec. Contact Cleaner). Now the Idle Airflow Control (under the throttle cable cover) doesn't seem to be working.

It's whirring when the key is position 2. All vacuum lines are cool, cleaned elec. contacts as part of the TB cleaning (with TB cleaner) MAF contacts, as many contacts as I could get to with the Elec. Contact Cleaner.

Any suggestions?

Post by **dborgers** » 08 Sep 2008, 22:11

PS I have no idea where the Throttle Position Sensor is. I did scrub the inside of the Throttle Body with a toothbrush, but not more than 1/2" beyond where the butterfly is.

Is it possible I somehow did something to it?

Won't idle on it's own at all without stepping on the gas pedal.

Do I need to reset the computer somehow? Unplug the battery?

I'm baffled and need some help. Thanks.

Again, the Idle Airflow Control is whirring when the key is in Position 2. So, I'm kind of baffled.

madorion · Post by **madorion** » 08 Sep 2008, 22:24

Wish i could help you db, it's hard when your car is your only car. Sometimes an extra pair of eyes can see the forest for the trees. I've had my Volvo now for a little over two weeks and I'm up to my neck in alligators as well!

Hey! prayer works! When I'm lacking in wisdom, you would be surprised how GOD reveals it to you! No kidding, I laugh about some of the stuff HE shows me.

GOD bless.
I hope you find what your looking for.

Post by **dborgers** » 08 Sep 2008, 22:35

Thanks, man.

I also have a Mercedes diesel, but this latest problem is just baffling.

This site is a Godsend !!

If you can, donate a few bucks to Matthew. He puts a whole lot of work into this site. It's saved me countless $'s over the last couple of years learning how to do basic stuff.

God bless you too !

jtslay · Post by **jtslay** » 09 Sep 2008, 13:49

Have you checked the vacuum line that runs underneath the fuel rail? Or what fixed my issue was new fuel pump relay.... good write up on it here...Jason

Post by **dborgers** » 09 Sep 2008, 15:16

Here was the problem:

I did not disconnect the negative terminal on the battery.

Thus, having cleaned the electronic contacts on the IAC (Idle Airflow Control - below the plastic shroud over the throttle cable) the computer didn't know it was there and wasn't talking to it - although I heard the IAC whirring.

Until the new MAF sensor gets here from FCGroton I'm gonna let sleeping dogs lie. The car is still stalling out. That's the only code I'm getting "121" MAF sensor (that sensor on the large air intake tube that runs off the air filter box).

I'm going to go drive for 30 minutes so the computer can relearn. But, still without the new MAF sensor it'll never be quite right until I replace it.

Thanks for responding ! I appreciate it !

Post by **dborgers** » 09 Sep 2008, 15:26

Oh, and while I was at it I took off the IAC and sprayed electronic contact cleaner in there 4 or 5 times, shook it, tipped it upside down to drain. First 2 or 3 times it was amazing how black the liquid was that came out. The valve on it was working fine, but looked pretty black.

When you take off the hoses and remove it from the rubber strap, just hold your palm over the bottom hole, then shake it, tip it upside down, and let the cleaner pour out. Then let it dry.

AGAIN!! : I'd suggest from my experience to disconnect the negative battery terminal before unhooking any electronic sensor wires. Otherwise, as I found out, the computer doesn't know it's in the system - and thus this thread.

Thank you for your kind replies !!

jtslay · Post by **jtslay** » 09 Sep 2008, 15:31

Just wanted to respond with this.....I went through a lot of things to fix the stalling issue.... new O2 sensor, coolant sensor, mass air sensor, cleaned throttle body and all parts to do with, fuel filter, complete tune up, and still was stalling, the fuel pump relay was the problem and since I replaced that relay I have had no issues for over two weeks now!

. I would have to say that there were several things leading to the stalling and am very happy with the car now. I even did the cold air intake mod from this site and noticable increase in performance

.. good luck and keep us posted.... jason

Post by **dborgers** » 09 Sep 2008, 15:37

Had you replaced the fuel pump relay recently and maybe had a bad one? I replaced mine about 10,000 miles ago. The previous owner had it, the fuel pump, and the fuel filter replace before I picked up the car in Ohio (I live in Nashville). He said it cut out like I described and would start after a couple of minutes - just like I'm experiencing.

Is it possible for so many fuel pump relays to be bad?

Just curious to know if you'd replaced yours recently and the one you mentioned was yet another new one.

Thanks man.

Post by **MadeInJapan** » 09 Sep 2008, 19:23

I have a spare one (for the just in cast inevitable) but with 165K miles on the odo, I believe I'm still running the original relay. Maybe I'm lucky or maybe some electrical glitches send more current to yours than it really should. Have you opened the bad one up to see if it's the solder joints or the capacitor? There's a write-up (I believe Ozark Lee contributed this) in the repair database that shows you what to look for and how to repair one with a new capacitor from Radio Shack.