[Ajmcmast]

Hi! I've got an older 190E, that while it runs great, the fuel/air ratio is off enough that my state won't let it pass the emissions test. It's idling in park at slightly above 1000rpms

I've replaced the ignition coil, distributor, cap and rotor, spark plug wires/plugs themselves, the 02 sensor, and I've tried to manually adjust it with the hex wrench method (note that the previous owner had changed it, I assume increasing the fuel), yet when it got down 700ish rpms, the car stuttered and tried to die, so that rules out that method for now. While in park the economy gauge is about 4/5ths of the way up.

Two other things that may be useful information is that I've got the magnetic fan and the auxiliary fan hooked up to manual switches on the dashboard, and there is one sensor I am unsure of what it does/what wire goes to it (I believe it is the water temperature sensor, not sure though, I've attached a picture of not my car, but another 190E, same sensor though), The wiring was mostly ripped out when I got the car and I've been slowly figuring it out. As the wires that are currently in the car, don't match any diagrams I've found, I'm a little nervous about just randomly attaching wires.

Sorry if there was an overload of text, but I'd be really appreciative for any help you folks could offer.

 

[Ignatz]

If you could locate another 86 2.3, and compare it with yours....then you could see if you are missing "cut" or "something" wires.

Why the previous owner eliminated the sensors for cooling could be many reasons. But if one of those sensors tells the fuel injection whether the engine is hot or cold...........then you got a problem.

If you can't return this car to its original state with the sensors, then you might be done.

Smell your motor oil, by just pulling the stick out and smelling it. If it smells like gas, then your car might be running like its "cold" all the time. Years back, some cars would actually increase the oil level by running so rich.

 

[dolucasi]

Agree with Ignatz, if that is the coolant temp sensor, that would explain everything.
Need to fix that first.

Unfortunately, if it is disabled the PO probably could not get the close loop to work, so he disabled the whole thing.
Likely when connected more problems will pop up.

After you get it working you will have to work on that vacuum meter to be full pegged to the stop. Otherwise you also have a vacuum leak.

First things first though.....

 

[plinker17722]

I would look for a vacuum leak .The economy needle should be at the far left on tick over .Can you inspect the fuel pressure regulator for fuel leaks /.The small pipe that comes out the back of it must not leak petrol . This petrol will get in to the rocker box and then down in to the sump .Dont pull the pipe out of the regulator but find the other outlet end and un plug that .

 

[dolucasi]

You will get many good and valid ideas from members like ignatz/trevor/myself and others however, the lowest hanging fruit there is to make sure your car is not operating in limp mode first.

Take a duty cycle measurement on pins 2&3 at the round diagnostic port by the emissions control unit when engine is hot and make sure it is oscillating around 50% and not stuck at a value.

And report on the findings.

After you pass this test, there will be plenty of things to work on down the road.....

 

[Ajmcmast]

You will get many good and valid ideas from members like ignatz/trevor/myself and others however, the lowest hanging fruit there is to make sure your car is not operating in limp mode first.

Take a duty cycle measurement on pins 2&3 at the round diagnostic port by the emissions control unit when engine is hot and make sure it is oscillating around 50% and not stuck at a value.

And report on the findings.

After you pass this test, there will be plenty of things to work on down the road.....

Just did this, it was hanging out at around 49%, so that should be okay, right now I'm looking around online trying to find pictures of similar 190E's and hunting Craigslist looking to see if anybody has one I can check out for like 20 bucks. I'm hopefully gonna check the fuel pressure regulator later, maybe I'll look into the EHA valve and how to test that (please god let it not be the EHA valve)

Arizona is a funny place, it seems like down here if somebody can't fix an issue they just rip things out and sell the car. That's basically how I got my 420SEL for so cheap, but at least that was an easy fix.

By the way thanks for the assistance everyone, I do appreciate it.

 

[dolucasi]

Is it stuck at 49% or is it bouncing around 45%-55%?
Did you give it some gas to move it from 49% and observe it?
If it is stuck at 49% then you are in limp mode. (should be 50% but not sure how accurate your meter is)

Not familiar with your engine but that sure looks like the position/motion sensor that is right next to the timing markers on the flywheel in the front.

Not sure what effect not having that is. Probably not good as your ECU is thinking the car is not moving or it may even put your car in limp mode. Take my words with a grain of salt on this though, ask an expert. Nevertheless if it is what I think it is it need to be hooked up.

Cheers!