need help finding the source of problem
 

car is a 85 euro 16v manual

i get low idle when cold and then as the car warms up the idle is around 1200
..
after doing some research i have traced it down to the cold starting system... the car has no cold starting system... i guess the previous owner turned the air/fuel mixture a tad bit richer so that the car will start without the use of the cold start valve.. HOWEVER that causes my idle to be about 1200-1300... also it has a very very weak cold idle and i have to give gas... i unplugged the cold start valve.. put the nozzle into a tin can.. got into my car.. and cranked when it was cold.. started the car.. turned it off.. CHECKED THE TIN CAN AND THERES NO GAS IN IT.. so apparently my cold start valve no work.. my water temp sensor is working i know that for sure.. so i decided to check the voltage of the wire for the cold start valve... no voltage on either wire!!!

Where does the voltage come from? maybe my wire is cut somewhere? where does the source come from? is it connected to a computer? could the it have fallen off? is there more than one device that the source has to go thru????

HELP MEEEEEEEE

I have no knowledge of your vehicle, but will say this.

There have been a lot of "professional" comments about the COLD START VALVE in this forum. That device is rarely considered to be an issue. It's used for a couple of secs. at start-up, then bows out.

Unless you're in the deep southern hemisphere where it's now winter and it's REALLY cold, this device is not likely the issue.

If I were you, I'd do some more digging in the archives.

My 2 cents.

well i live in Southern CA and its hot as hell...

but my problem is that... when im cold.. it takes about 30 secs to crank... and when it starts.. the idle is around 600.. for cold starts my car is suppose to be idling at about 1200.. as it warms up it is suppose to slowly fall down to 950 rpm...

right now my car starts at 600-700.. and then as it warms up will raise to 1200 and be at 1200 for the rest of my ride..

I JUST bought this car about a month ago.. so i am guessing that the cold starting system is DOWN.. and a mechanic or the previous owner just turned up the air/fuel mixture to rich... so that it will be able to start... WELL it does start now after awhile but maintains a very low idle and sounds like it is about to die.. and idle higher than normal when warm...

I dont know if i am right but i think i have to fix my cold start and then go ahead and lean down my A/F mixture... right now i cannot lean it out.. if i do.. it will not start

if anyone can diagnose the problem with my car from what i have said about my cold and warm idle.. PLEASE LET ME KNOW

as of know this is my idea:

fuel pump relay
i looked at my relay and it says 6 zyl.. 6200 rpm? my car is a 190e 16v... maybe the old one broke and i guess the previous owner went to a junkyard or something and found a 2.6 fpr to replace it?

could this be why my cold start valve is not working?

i read somewhere that the voltage supply for the Cold start Valve is from this relay?

ANYONE?

I second that opinion, the cold start valve isn't going to affect the idling of your car unless maybe it keeps operating. Also, please give specific details about your car...Model, Year, Engine, etc.

I would do a tune-up, including new spark plug wires, and clean the throttle housing, then re-adjust the fuel mixture. Do one step at a time and make sure the engine starts. I have owned my 1993 190E since new, and about 2 years ago I cleaned the throttle housing and it made a huge difference when first starting the engine cold.

On another forum a guy replaced the fuel pump, fuel filter, all tune-up related parts and the car wouldn't start. After trying and trying to get the engine to start, he finally determined that he mixed up the spark plug wires.

Good Luck,

Dave

my car is a 1985 Euro 190e 16v
I have no X11 Pin #3 because the car is euro
when ti was imported they had an oxygen sensor and cat installed.

can someone tell me exactly the behavior of a cold start valve?
when does it activate? how long does it stay on for? or from wat temps does it stay on?

this problem is so frustrating i have tried everything

also wat would be a sign of a broken EHA?

i have no specific info regarding your engine, but your logic seems good to me. dont give up.

in general i agree with the posters who say that cold start valves rarely are the problem.

that said, i think you should be getting some fuel out of it on a cold start.

tom w

wat are the other devices or parts in a car that control cold starts?
i know that the
fuel pump relay sends signal to the cold start valve..
ovp also has something to do with it..
water temp sensor is the thing that produces the signal by reading the engine's coolant temp..
the signals are processed thru the CIS
the fuel pump is also the part that sends the fuel.. (however my car runs fine when warm so i doubt it is the fuel pump)
lamda also affects air/fuel to a certain degree

ON that car & most MB's thru 1989 the cold start INJECTOR has little OR no effect on the starting OR running of the engine EXCEPT during cold weather...below 60F.

You are barking up the wrong tree.. cold starting during the summer (& winter) is done by changing the fuel pressure differential. The larger the differential pressure the richer the mixture..

Having the control current (amperage) with key on & during starter operation to the EHA checked is the correct starting point!

I will test the voltage of the EHA current tomorrow and let you know
Thanks a lot!

Not a voltage test but measuring amperage...should be 20ma. with key on..

You have to measure BETWEEN the computer & EHA with ammeter.

And you use part number 102-0463 - Test Harness - EHA - Page 14 at the Baum site below to do the amp check with:

http://baumtools.com/Baum_Tools_mercedes_catalog_2006.pdf

checked the amperage of the wires to my 1985 190e's EHA and it reads 7.9 mA
checked the amperage of my 87 260e's EHA wire and it reads 20 mA

wat does it mean?

do the older MBs have a different amperage than the newer ones?

I think I am also getting bad MPG as well

UH OH
i read somewhere about taking out the EHA and turning it clockwise a little and it would fix my problem... i ended up taking out my entire air flow sensor along with the fuel distributor...

took off the EHA opened it up and turned it clockwise a little.. open up the air flow sensor and cleaned the air guide and the top half as well... thought it might help air flow..used engine degreaser on those parts.. there was a throttle body on my intake manifold so i opened it up and cleaned inside a little.. used engine degreaser as well... bolted everything back up and stuck the EHA on... and put the entire thing back on the car...

HOWEVER now my car will not start... i got it to start once or twice with gas... but then it died right away... but it will not start anymore..

i took the eha out again... turned it CCW and still did not fix my prob...

richen my air/fuel and NO GO still

can anyone help me??!?!?!?!

haha fixed it..
forgot to plug in the pipe for the idle air valve..
gonna try to turn the EHA again and see wat happens

190e-16
 

i had one of those cars which i bought cheap because it wasn't running well.it was necessary to richen the mixture to get it to start and then it ran at 1200rpm.after i bought it i replaced the 10 amp fuse in the top of the overvoltage protect relay and all was well.with that fuse blown[these cars tended to blow that fuse when being jumped because of dead batt]you have no power to the main fuel injection which also runs the auto idle valve[this valve requires power to close it down].do you remember the audi unintended acceleration in 1985-86,they used the same vdo valves.all the euros changed to a valve that remained closed until powered up for reasons of liability the following year. anyway check the fuse if you need more help call me. david poole european performance dallas tx.214-9567007.

well ive been messing with the EHA adjustment and it hasnt help at all..

also yea my car is suppose to idle at 950 when warm and start up at around 1200..

instead it starts up really weak and then when it get warm it idles high at 1200.. which is why i am getting bad gas mileage

i think the reason it is idling at 1200 when warm is because the previous owner couldnt get the car to start up so he had to richen the mixture so it would start...

but that in turn makes the idle higher when the car is warm

AND i cant pass smog either GRRRR

hey david when u car ran at 1200 rpm after u richen it.. did it still start up with a low rpm when it was cold? i had to richen my mixture a little more to get it to start... but now i cant fix my high idle.. it is also really weak when it starts

btw i took my OVP out of my 87 260e and put it into my 190e to make sure my OVP was good.. with the other OVP in place.. it started exactly the same and ran the same.. no difference..

also I was wondering...
if i have an X11 off a NAM 190e 2.3 8v..
can i transplant it into my euro 16v?
or is it more complicated than that?

right now i cant check my duty cycle because i have no X11

if i cant transplant the US X11 into my Euro.. is there any other way to set my air/fuel mixture other than buying a gas analyzer or taking it in?

okay so i called david and i decided to just take out my OVP and see wat happens..
Strange thing is.. without my ovp my car starts the same and runs EXACTLY the same

I have a 1985 and this car has the old idle control valve... in 1987 they changed the idle control valve...

does this tell anyone anything? i am guess i either have a bad idle control valve or I have no supply controlling my valve so its always open. I say always open because if it werent working it has to at least be open all the time or else my car wont start.. it obviously wont start if the valve is shut because there would be no air running thru

im thinking the car's valve is always open... so when i first start it.. the engine is getting overloaded with to much AIR so it has a low rpm... and when it is warm it is getting alot of air so it is at a high rpm *shrug*

let me know wat u guys think

Well you can remove the top hose to the idling valve and check if your suspicion is correct. With the hose off you can see what position it's at when you turn the key to position 2.