Idle problem in 420SEL
 

Car is an 89 420SEL with 180,000 miles.

The car is idling a little high at around 1600 rpm. I swapped the idle speed motor out of another car and no difference.

By removing the air cleaner and pulling up on the throttle plate, to restrict more air, the idle drops down to normal. Throttle plate seems to be vacuum actuated. I have looked for vacuum leaks and did not find any obvious ones.

Also, what are the air conditioning lines that run to fuel distributor for?

Thanks

Any one got time to help me out on this one?

ABS light on ?

still trying to figure my hi idle
good thing its mostly when cold started & it idles fine in drive.

1600 is very high

mine starts 1200 then can go to 1500 as it warms then down to 900

I had a few obvious vac problems
but they really haven't resolved it
also got a weird warm up reg config.

start by searchiung for hi idle

narrow it down
does it do it all the time & in drive too?

ABS light on would point to OVR... My ABS light isn't on but wonder if it could still be an intermittent problem but wouldn't that mean it would idle fine at times?...

did it just start or did you get the car like that?

someone might have it all off

so many things can affect idle so you have to ry to narrow it down

seems you are getting to much air
so might be a leak somewhere or a faulty valve..

I don't know & am basically reading & hoping to find something thats an easy fix...

Good Luck

<ABS light on would point to OVR... >

ABS light On would point to blown OVP fuse, but no ASR light does not eliminate OVP as possible fault..........

Thanks, so mine is not blown then
but as you are saying they do get old
heat etc wieakens contacts & they act as gremlins messing with our sanity...

Its not a cheap fuse but I have ordered it & at least I will have a good one.

Thanks

:D

A flacky one will sometmes show up if you tap it while car is at idle..the idle rpms will change as yuo tap the relay, verifying bad connections at solder joints.

How about an Idle Control unit. I tapped mine and it killed the car. Thought it was a coincidence, but started it again and it was idling high and low fluxuating between 1500 and 1000. Tapped the ICU and it killed the car again. Also I tested the ICV and with it disconnected it started without accelerator being used and the rpm cold was 1100, tried the same test hot and it started right up with no Accelerator assist but rpm was 1500. I have a new OPR coming, but I think I need a new ICV too. The ICU thing is just thrown into the mix.

Vacuum leak? Check for vacuum leaks then do the electrical stuff next. I am having an idling problem and have replaced the OVP and MAS and car still doesnt run so point is you may not need to replace the ovp because it could be one or many other things to look at.

May seem like the bllind leading the blind
as I still can't find my ICV
but I have heard you can try to clean they out.
Worth a shot


I got a new OVR coming so I might putoff tapping it til the new one gets here but guess it would be good to know if old one is still good.

Relay slowly went on my volvo
a year or 2 of worsening gremlins
finally she stalled on the street
then wouldn't even start at all for days

took it in they changed some $50 relay, charged me $225 & its fine

Had I had known...Hmmmm

ICV valve is on the left hand side of engine where the manifold is.Towards the front. If you need some documents send me a pm with your vin and email addy.

Left as you look at engine?
Do you see it
Its a euro & things are bit different..

I've been looking....still can't find it

http://www.peachparts.com/shopforum/attachments/tech-help/48105d1190784590-500sec-fuel-system-problem-mbengineintake.jpg

http://www.peachparts.com/shopforum/attachments/tech-help/48164d1191034112-upgrade-83-mer-500-sec-88-volvo-gle-mbposicv.jpg

http://www.peachparts.com/shopforum/attachments/tech-help/48102d1190781760-500sec-fuel-system-problem-mbintaketop1.jpg

My apologies

On the north American model its on the right side of the motor where the all the fuel system parts are. more toward the front of the car. Ill try to post up a diagram for you.

I just posted a picture of my engine with the location of my ICV in my 380 SE. On the upgrade thread that CS started.

No abs or other lights are on. Idles at 1600 when in park or idle. Idle drops to around 700 rpm in drive. If you take your foot off the brake, slowly accelerates to around 15 mph and 1200 rpm.

I have an 87' 560SEL parts car that the engine runs fine that I can take parts off to try on this car.