About a week ago, I took the injectors out of my 8V engine but only on Cylinders 1 and 2. I looked at the condition of both injectors and then put them back in. When I started my car, it started to idle irratically and it would stall when I moved from stop. Above 2000 rpm there is no problem and the car is a rocket. Another problem is hard start. All these problems went away for about three days...I was very happy. Then it came back two days ago. I got brand new injectors, even a brand new Overvoltage protection relay. I replaced everything but the problem lives....what could it be? I have to drive 50 miles everyday to school and back and it frustrates me.

Well, maybe this will help or maybe not...
I had a somewhat similar problem. I fired the engine, very
briefly, with an injector unplugged. Ran as you described afterward. I pulled the battery cables...replaced them..I'm guessing this reset the computer...and in about 2 minutes it ran ok. Good luck...

Yeah I thought that I needed to reset the ECU (the computer) as well, so I did as you said and reset the computer...the problem did not go away...I dont know what else to do..Help me please!!!!

My guess is that the rubber donut seals around the injectors you pulled are not properly sealing after being disturbed. These will dry out and harden from heat and age and should be replaced frequently. They are also very cheap. The clamps that hold the injectors in place on the 190e do not put a lot of pressure on these seals. You likely now have a vacuum leak on these 2, which you wont notice at higher engine speeds, but will at idle.

You are correct, but I have purchased brand new injectors with new seals. Dont you think that that would correct the problem? again I am clueless at this point...thanks for your help...anymore ideas of what it could be?

I would think it should. However, as I recall, I had to fight a bit to get evrything out and back in on mine. It's possible that one of your fuel lines is putting a slight sideways force on one of the injectors, preventing it from sealing properly. You can eliminate these seals as a possibility if you have access to oxy/acetylene torches. Idle the car, turn on the oxygen only on the torch, and quickly wave it near any suspect seals. A vacuum leak will announce itself with a quick increase in engine speed as the oxygen is sucked in. CAREFUL!!! Do not hold the oxygen near a leak as you can damage your engine if you continue to let the engine suck it in. Use this method to just QUICKLY identify the leak points.

Its about 1:45am right now and I just got done putting a new fuel pump in my car. Nothing happened.... the problem is getting worse..it looks like I have lost two of my cylinders. I have no problem with it on the highway. The 190 starts losing it when it falls below 2500 RPM and starts to hesistate. So far, I have changed Overload protection relay, injectors and fuel pump. At this point I am absolutley clueless
Thanks for the reply

It may be a stretch, but I had the exact same symptoms after an injector was replaced a coupleof months ago on my 190e. Turned out the mechanic failed to reconnect the air breather vacuum hose coonected to the bottom of the air cleaner. Problem was solved immediately upon reconnection. Have your checked this?

Brian

Yeah I have already done that... as a matter of fact I bought a new breather hose about a month ago since the old one was cracked. I dont think that connecting of the breather hose should make that much of a difference. Well I might be wrong again...thank you very much for the reply. Oh by the way, did your car hesitate badly uopn acceleration from stop? At this point I think that I am running a lean mixture... thanks again.
Sean

Sean:

i've read it somewhere that you just do not simply
replace injectors. the new injectors must be pushed
open by air pump pressure to function properly. Do a
search on this website, or click on to http://www.mercedesmailinglist.com/ and go to archive.
hope this helps.

Before changing the injectors, I read the MB CD manual carefully and there is no indication of what you said...hopefully its a simple problem....Thanks for your reply.

190 Injectors
 

It is possible that you got bad injectors. Leaking ones. The last time I bought injectors, my parts friend at the dealership implored me to check 'em.

He was right: one out of the six was bad.

Just a thought.

Jeff

This problem started when I took my old injectors out and put them back in again. Later when it got worse, I bought new ones and the engine kept doing the same..So I doubt that its the injectors. Thanks for the reply