1990 190E 2.6 random stalling
 

So as the title suggests, I have a random stalling issue. The car idles perfect, but what happens is that If I start the car up it turns on and idles fine in park ~700 - ~800 RPM, but when I put it in reverse there is that brief period where the idle adjusts and drops down to about 550 - 600 RPM, but the car dies. Also if I'm in park and the car is idling if I tap the gas pedal lightly to bring the RPM to about 1000-1250 RPM when it drops to stablize it will die sometimes, but sometimes not. Same thing happens on occasions if I'm stopped at a light, the idle will be perfect and steady at around 550 - 600 and then it will just die. Nothing happens as a warning it just seems to cut out, all dash lights come on and I end up shifting the car to neutral and restarting it. My recent repairs within the past 6 mos to a year are as follows:
New O2 sensor
New non-resistor spark plugs
New distributor cap
New wire set
New 120 amp alternator
Upgraded 2 AWG wire for aternator
New battery
Valve cover gasket
Oil filter/oil change
Timing cover gasket
Shifter bushing
Rebuilt transmission/fluid/filter/gasket included
Fuel pressure regulator
Fuel filter
Cold start valve
OVP

I have checked/cleaned IACV. Recently checked/lubed small piston on EGR as it was sticking. Attemped to richen up air/fuel mixture. Tested fuel pumps. Turned on ignition to get pressure and then opened main fuel line to distributor to check fuel deliver (wear goggles if doing this). I am at a loss :confused:. Only thing that seems to maybe help is that if I'm in park is that when I shift to reverse I immediately give it a bit of gas to keep the RPM up a bit so that when it drops down it doesn't cut out.

On a K-Jet system this behavior is usually a vacuum leak, typically a hardened or split idle control valve hose or a petrified air meter horn the throttle body boot.

All those parts must be flexible, if they are hardened you should replace them.

I fought this battle with the TE, and finally even ended up replacing the o-rings on the fuel injector holders that no one knows exist.

Also check for the condition of the ignition wires and spark plugs, as bad ignition will result in improper fuel mixture, at least when warm.

Peter

Thank you! I have changed out everything except those. I'll order them.

One of the nuts on the ignition coil was loose on mine, and caused intermittent stalling.

Found out when we shut off the lights in the garage and saw there was a spark with the ignition coil cover off!