1988 190e 2.3 rough idle/stall - PeachParts Mercedes-Benz Forum

mespe · #1 05-19-2007, 10:18 AM

Well, I bought my oldest daughter a Benz for a graduation present. Now I just gotta get it running good before I can give it to her.

I've only had the car for <12 hours and here is what I've noticed.

When cold (first start) starts up and idles arounf 1700 RPM, then it drops to 1500 RPM, but as soon as you give it a little gas, the idle drops and she stalls, unless you keep pressure on the accelerator pedal.

Runs smoothly when it's running (with gas pedal depressed) coughs and sputters when not pressing on the gas pedal. Also noticed the drivers door lock vacuum pod is leaking, not sure if it's tied to the engine vacuum or not.

Haven't checked anything (like plugs) but I noticed the spark plug wires are hard and not flexible, guess those are area's I should start (plugs and wires)

Any suggestions would be appreciated.

I will keep this thread alive with updates and new questions.

david s poole · #2 05-19-2007, 10:48 AM

plan on replacing the fuel distributor it will save a lot of headaches.

mespe · #3 05-19-2007, 12:46 PM

Well the car has platinum plugs,,, I've read a few posts that say only copper,,, why only copper?

david s poole · #4 05-19-2007, 01:05 PM

because platinum plugs are resistor plugs and that eventually causes the distrib cap,wires and sometimes ignition unit to burn up.

mespe · #5 05-19-2007, 02:47 PM

OK platinum plugs will be gone. Working on the car has been delayed because I broke the little rubber hose between the fuel pressure regulator and breather hose. I'd prefer not to throw a fuel distributor at the car first thing. I'd rather change out some cheaper parts, the car will run fine when I give it some throttle,,, can the fuel distributor be cleaned? I would think (here I go now) that if teh fuel distributor was bad, the car wouldn't run good at any time,,, am I wrong?

mespe · #6 05-22-2007, 11:16 PM

Since i couldn't work on the engine (other then look to see if there is an offset woodruff key in the cam - no there wasn't), I bleed the brakes. The brakes were really scary, like there was a pocket of air in there,,, well I found the air, it was in the Right front caliper. I went to bleed the caliper and nothing came out. My hand got a workout squeezing that mighty vac ,,, getting it up to 30 inches, but no go, it would slowly return to zero. I took the bleeder completely out and it was corroded. Using one of the little rubber fittings that came with teh mighty vac, I proceeded to insert the fitting into the bleeder screw hole. Jammed it in there good and tight. Another workout squeezing the might vac, nothing. So I went into the car and pressed the brake pedal with the bleeder screw removed - but might vac hooked up with vacuum and the brake fluid started to flow. I then continued with the brake bleeding and got a good pedal back. Now if I can only drive the car,,, gotta fix the idle problem,,, I noticed that the ignition timing is retarded to the max, and I got to wondering if maybe timing chain stretch is the reason why the car won't idle. So I gotta figure out how to check timing stretch on the 2.3's

mespe · #7 05-23-2007, 09:14 AM

Well I think I found my problem,,, see thread titled 3/4's of a tune-up = rough idle/stall will included picture

just-n-time · #8 05-23-2007, 02:03 PM

Yes that a good reason for poor Idle.Now for the caliper right front, I don't wish to alarm you but to me it sounds as if you have a stuck piston. If it was my daughter driving the car, I would remove the caliper and rebuild or exchange it for a rebuilt unit. Look at the pads, are they the same thickness? If not you have a sticky piston.JNT

just-n-time · #9 05-23-2007, 02:13 PM

Oh yes do your self a real favor,If the past owner was so lazy as to let the last plug fend for itself,I would do a complete tune of the engine. Wires,plugs (non resister) rotor, cap,then you can set the on off ratio,with fine tune of fuel.Are you the indy or do you have some one to help you?

mespe · #10 05-23-2007, 04:19 PM

I'm just me,,, no indy, unless you mean individual. I will keep a close eye on the Right front caliper,,, I'll be driving the car a few weeks before I give it to her,,, eventhough that means I can't drive burning WVO.

Would very much like to learn how to adjust the ratio,,,

mespe · #11 05-23-2007, 07:14 PM

WEll,,, we're almost there, but she still stalls. Starts right up, idles for a few seconds and then stalls, unless I give it some throttle. Tried a few times, same symptoms. One time the idle did continue, but it was at around 1100 RPM a little to fast.

I also noticed as the car starts to stall, the economy gauge (read vacuum gauge) starts moving toward the red.

The car doesn't skip or miss anymore, but the problem has not been solved,,, unless I put the ICV in backwards.

just-n-time · #12 05-24-2007, 07:21 PM

No you did not put it in backward.Do you have a multimeter? Is it digital? Can you read percentages?(with the unit) ha,It sound like the fuel may be lean.check several post I have on the subject,plenty of info on fuel setting. Try all off that then if it just will not act the way it should,go with what Dave told you. JNT

just-n-time · #13 05-24-2007, 07:32 PM

Oh yes I forgot, You will need to check the EHA. and Potentiometer,The pot is what keeps it from dying or dipping to low in the RPM's on deceleration. you may also replace the oxygen sensor. this tells the EHA that it is running rich or lean and has a great deal to do with an even balance in the running. Good luck, let us know how you make out. JNT

mespe · #14 05-24-2007, 07:53 PM

I measured the volts coming out of the O2 sensor,,, got .1 when the car was running it jumped aorund to .4-.6, but at idle .1 I figured it was bad so I replaced it. Now I get around .4-.5 at idle. But I'm still having issues.

I measured the Lambda (X11 pins 2&3) and I got 10.6 volts or a ratio of about 15% MAy off. Even with the new O2 sensor,,, same reading. If I press on throttle (enough to switch teh microswitch on the throttle, the Lambda drops to 3.6 or so. which is prol within reason. Whenm the car is cold,, it'll stall until it warms up, after it warms up, the idle is around 2000 RPM and won't come down.

mespe · #15 05-25-2007, 05:07 PM

Got her running without stalling!!!

Here's what I've done to get the car running,

1) Replaced some of the hardened rubber hoses going to the air cleaner and ICV.

2) Cleaned and tested the ICV

3) Inspected OVP

4) Checked and replaced O2 Sensor Bosch 13953 (cut and splice fits Fords

5) Checked Timing chain stretch - none noted

6) Removed #4 spark plug that was cross threaded and gapped about 80/1000's

7) Ran a thread chaser (Napa, the one at advance auto was stubby and wouldn't fit in the spark plug cavity)

8) Replaced all plugs, even though 3 of them were platinum "super duper" plugs - see thread 3/4's of a tune-up

9) replaced scotch tape on accelerator cable and installed the proper fitting

all this didn't fix the stall issue,,, but tweaking the fuel mixture screw did

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