HI,

I've been trying to fix my cold start problem for a while now.
Someone suggested to check the fuel mixture so I bought a multimeter that reads duty cycle pluged it on x11 pin 3 using pin 2 as ground .
The reading I got was 10% with ignition on and also when engine running and it is not fluctuating at all. If I just turn ignition on I get 10%, If I press on throttle plate I get 49%. if I go full throttle I get 79%, never fluctuating.
I tried to adjust the mixture but it always stays at 10% whatever I do.

I been reading the post about how to adjust mixture, or I am doing something wrong or I didn't understand what I read.

can someone please help me.

Thanks
AJ
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Are you letting it run long enough for the 02 sensor to warm up?

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2012 E350
2006 Callaway SC560

HI, Thanks for helping
I read somewhere that the car needs about 17 miles running to get to temp.
So that is what I did I went for a small run did about 20 miles came back home and that's when I have started the test.

Thanks
AJ

It really should not require nearly 17 miles to get it going.

Seems like it's not going into closed-loop. Many things it could be, but I would probably look at the 02 sensor first. How old is it?

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2012 E350
2006 Callaway SC560

I just replaced the o2 sensor about 1 months ago, ********az offered me a Mustang o2 sensor they said it was the same thing without the connector.

AJ

check the coolant temp sensor, it's a place to start

do you mean water temp sender?

Thanks
AJ

No, the Engine Coolant Temperature Sensor. It sends engine temp. information to the CFI Control Module and the Ignition Control Module. Controls activation of the cold start valve circuit.
It would help if we knew the year and model of your car.

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1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

HI,
My car is 300e 1990 3.0
Looks like mine has 2 prones am I right. I already replaced the coolant temperature switch the 4 prones one.

Thanks
AJ

Why don't you go ahead and tell us what all you've replaced.

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2012 E350
2006 Callaway SC560

AJ, here are two possibilities:

1. If you are using a Sears-type meter (set on freq/duty cycle) be sure to
press the upper left button to go from the "frequency" mode to the "duty-
cycle" mode. If you don't do this, you will be reading the "frequency" of
the signal, not the duty cycle. (I know, I did this).
a. Switch on freq/duty cycle
b. push upper left button to display DC.
c. red wire in hole #2, black wire in hole #3 (backwards from expected).

2. The engine manual says if you are seeing a constant 10% DC, you could have:
a. Bad sensor air volume meter connection. (don't know much about this
one, probably a reostat that could be checked like a throttle position
switch?)
b. Throttle valve switch not contacting, or defective.
(the throttle valve switch is on the linkage, should click when the
throttle is cracked open. Also, pull the wire and see if it changes
continuity when it clicks).

DG

At idle and full load= 0 ohms.
Partial load= infinity.

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1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

Hi,
Here are the parts that I have replaced.
-fuel filter
-air filter
-OVP
-Cold start valve
-Coolant temperature Switch
-engine temp sensor(at Air Filter Housing)
-Fuel Pump check valves
-spark plugs (bosh non resistor)
- added techron twice.also ( I only use Mobil gas )
-Sea foam treatment
-checked injector and vacuum hoses with starting fluid for leaks.

Thanks everyone for helping I really appreciate.
AJ

You said you checked vacuum hoses. Did you check the vacuum hoses going to and from the Idle Control Valve? Especially the one on the bottom going to the bottom of the air flow housing.
Did you check the Crankshaft Position Sensor?

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1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

HI, The crankshaft pos sensor wasn't check yet, still looking for info on how to test it.

There are a lots of thread about it but some say the only way to check it is with a scope.

Thanks
AJ