Bad idling on '93 850

Dunoyer · Post by **Dunoyer** » 01 Apr 2006, 11:43

I replace a cracked hose connecting the throttle body to the air filter element. I sprayed some cleaner in the throttle body. I cleaned the contact to the throttle position sensor, and now I am optimistic that my beloved 13 year old Volvo will purr like a kitten.

Here's another thing, though. Out of the air filter element is a metalic hose which travels toward the firewall, it connects there to a metalic piece in the shape of a hat which is flush with a heat shield. Mine was totally lose and half eaten by corrosion and I have removed it. What does this do and do I need to replace the corroded part, or just let that hose hang, it appears to be an air exhaust.

Jean

Post by **MadeInJapan** » 01 Apr 2006, 14:53

Sounds like the secondary air solenoid. Yes, it should be connected. If you don't have anything, cut the part that was messed up and use it shorter. If it gives you problems, you'll probably only have them on start-up, but still, nothing should be loose on your Volvo. Good luck.

Dunoyer · Post by **Dunoyer** » 01 Apr 2006, 18:32

I just drove the car into town and back... Wow! What a difference, the car totally runs perfectly. I can't thank you enough, It only took me an hour and cost $50 in parts and supplies. I'll replace that corroded part, and keep checking in when I get stumped.

Thanks again, MadeinJapan.

Jeanjavascript:emoticon(':lol:')

Dunoyer · Post by **Dunoyer** » 15 May 2006, 18:49

6 weeks later... What to do?javascript:emoticon('

')

Post by **MadeInJapan** » 15 May 2006, 20:53

What do you mean, what to do? Not good again? Everything good? Let us know.

Dunoyer · Post by **Dunoyer** » 15 May 2006, 21:07

In one month, my beloved 850 went from running like a dream to idle hunting, stalling, surging, etc. again as before. Something tells me a new harness might fix it but the part alone costs $1,050. My mechanic thinks it's the central processor, and I'm frustrated because all of these are diagnostic repairs, meaning spend the money to replace something, if nothing improves, you know it's not that. In the 21st centurt, we ought to have better diagnostic tools than that! The car is very solid otherwise, so many cars of mine have succumbed to intermittent unexplained electrical problems.

Thanks for listening, and perhaps, helping...

Jean

Post by **matthew1** » 15 May 2006, 22:40

Jean, Check vacuum lines and mass airflow sensor first, those are easiest to find/fix/buy if it's them.

Do you/your mechanic know the codes your Volvo is throwing?

Dunoyer · Post by **Dunoyer** » 16 May 2006, 04:53

That's the BIG problem: no codes!!!

Post by **akitawagon** » 16 May 2006, 23:32

You mentioned you only cleaned the throttle position sensor.

From reading about some other people's experiences, just cleaning the TPS gave them a temporary fix, but the initial problems with the "idle hunting" returned.

Before spending lots of money on a harness, try a new or certified used TPS first; it's a lot cheaper. Also, check your vacuum lines and MAF (mass airflow sensor) as Matthew suggested.

You may not get an error code until the TPS finally fails or becomes less than marginal. I didn't get the code for the TPS until the "idle hunting" got really bad.

Dunoyer · Post by **Dunoyer** » 17 May 2006, 05:18

Thanks.

Can you describe to me what "checking your vacuum lines and MAF" entails?

Jean

Bad idling on '93 850

Done!