Tonskul

Hello!
I've been wondering all of those correct adjustments for fuel distributor / electrohydraulic actuator operation.

I only have mA meter to measure EHA current, no duty cycle measurement possible. And this is what I get:
At idle, it hunts around 4mA (+/-1mA) and lambda voltage hunts beetween 0.2-0.5V. So it is running closed loop as it should.
At 2000rpm, Lambda voltage is more stable at 0.4-0.5Volts, and EHA current hunting beetween 5-7mA.

On overrun conditions (fuel cut off), meter says -60mA.

At wide open throttle, there is not much difference, EHA current around 7mA and lambda gauge says it is running rich (>0.7V). Why so little difference in current at WOT conditions? As far as I know, ECU should richen the mixture (should be measurable in EHA current going up) and work in open loop mode for WOT?

Fuel mixture screw in distributor is untouched, still having the shield. So it is having original adjustments. However, EHA has been adjusted previously. There is small 2mm allen screw behind that can be used to lean out or richen the basic mixture.

Main problem is that after I repaired some vacuum leaks and adjusted basic ignition advance to the factory defaults (15deg. btdc), it lost some low end torque!
It pulls just fine from 2000 up to 5500rpm but below 2000rpm it is a little bit sluggish. There was noticeably more power/torq below 2000rpm before all of these repairs, as well as some pinging at heavy load + cold engine.

So maybe it has something to do with ignition advance or what? I want that low end torque back!

x19

Hi, Try this way,
hook up DVOM on connector of O2 wiring (green) and DVOM shows the swinging voltage 0.2 ~ 0.9. If not, you have to turn the screw (fuel mixture, use 3 mm aren wrench ) in or out until you see the DVOM swing, If you have still same like under 0.5V, check a vacuum leak at the intake boot, vacuum hoses, injector seals and (or) intake manifold gasket etc.
BTW, how many miles on your car ?

Tonskul

My car has 330 000km.

At idle and cruising speeds, mixture gauge (connected to lambda sensor) swings around 0.2-0.6Volts. So it seems to be just fine. On hard acceleration (WOT), gauge says rich mixture, so > 0.7V.

EHA current: 5...10mA in different loads and idle (8.2-8.4mA at WOT).
It should be more like 0mA when idling and while cruising (-/+1mA).

I just have no idea wether to adjust EHA valve or fuel distributor idle mixture screw.. as far as I know, idle screw does not affect mixture under load? Or does it?

And then, about ignition timing. Someone says that breather hose should be disconnected and blocked while adjusting ignition basic timing (as well as idle mixture!).
Why is that?

x19

Well, have you see the floating plate after removed intake boot and see the plate face,
you will see the so much dirt on it. Cleaned the F/Plate and reset idling mixture.
Also. low end no power? check the inside of distributor, centrifugal mechanism stuck on shaft or pour small amount of oil to shaft after removed distributer rotor.

x19

Are you talking about Fuel Control Pressure regulator? If so, here is one from our member posted on another forum?

CIS-E: Troubleshooting and tuning

I hope this one help you.

Tonskul

My car has electronic ignition control (knock sensing system)..

Still not working as it should.
EHA current at idle: -1...+1mA, cruising: 2...4mA.
Idlespeed: jumping beetween 900-1100rpm continuously. Stops jumping if EHA disconnected.

x19

Did you see the plate after remove the intake boot! I believe you will see dirty stuff on plate and you have to calibrate the mixture after cleaned the plate. you have a factory sealed (plug for mixture screw) over 20 years and also, it's time to see the condition of air cleaner(not easy to replace A/filter). You have to find out mechanical problem first and then dig in to electric problem. That all I can say and you chase the tail on dog or? Give me a parts (BOSCH) number on it if you can see like 2 437 020 005, Differential Pressure Regulator for richen gas that we call. Good luck.