95 E320 Stumbling Idle
 

I have the same problem as JetForeman who posted in this Forum few days ago. For the last few months, my 95 E-320 w/63k miles sporadically stumbles at idle only when in drive. a/c on or off no difference. After a intial stumble, it will idle perfectly. That is until I go to another stop and then it happen again. The car run fine and it has never stalled out. I took it to the MB dealer. First time, they told me that a MAP connector was loosing, they reconnected and charged me $130.00. The problem did not go away. Complain to service manager, brought the car in second time. They told me that water was in cylinder #5. They clean it and they told me the problem was fixed no charge. I took it home, and the problem comeback. Please help me.

JetForeman, if you read this message, please let me know how do you fix your problem.

hesitation
 

i have similar problem however check engine light is on codes 5 and 10 from onboard diagnostic led in engine compartment near battery. symptoms sound the same as yours, hesitation when resuming acceleration from a dead stop and this is intermittent.

Re: hesitation
 

Assuming you have the same model, the first thing to check is the EGR valve for sticking . That is code 5 and they have up-graded the egr valve due to sticking. [ Benz TSB]
At the same time , check for air flow through the egr to intake
pipe... another common code 5 tripper..
From there , I would clear codes and run it to see if 10 pops
again before condemning the MAF sensor [ 10 ].

94 E320
 

thanks for the info
it has 151k miles and is an 94 e320. i will check the items and update back.

Re: 94 E320
 

Mine does not have check engine light come on. The dealer run the code test and found no faulty code. After the problem started, I did replace spark plug, fuel filter, air filter and put fuel injection cleaner in the gas tank. The problem is this is intermittent problem. Could it be ECU or O2 sensor. In JetForeman post, he replaced o2 sensor. Do you think this problem is caused by O2. I check the sparkplud wire, they look o.k. no leakage spark to the engine block. MB dealer told me that if the problem still exist, they suggest to install a ignition booster cost about a couple hundreds. Sine they lost my trust, I do not think this will solve my problem. I already ordered the CD Shop Manual. If you have a solution, please share.

duc
On yours , I would change the 3 boot/resistors under the coils before going any further..
Specially as they found an ignition prob/h2o on one plug ...
These are common fault and should be changed when changing plugs..

Thanks Arthur. I will change the ignition boot under ignition coil. How difficult to change. Is it expensive to buy the boots.
I will report the results later.

They are about$7-8 ea right here at Fast Lane..

If you changed the plugs, the job is the same except you don't have to pull the plug, just pull the old boots off the coils and push/snap the new ones on.

You may want to check your mass air flow sensor too. I had an erratic idle problem with my 94E320 before. I replaced the spark plugs and boots. cleaned the egr tube, replaced the fuel pump relay and check valve. The problem didn't go away. Since the mass air flow sensor is expensive around $250.00, I repalced it last. The problem went away.

changing the coil to plug boots cured this exact problem for me. misfire diagnosed on #6 cylinder. check engine light never went on.
try this first, cheap and easy.

See my post to another spark plug inquiry.

http://www.peachparts.com/shopforum/tech-help/46116-spark-plug-help.html

Same for my car. See my signature below. One cylinder was misfiring because of a bad boot on one cylinder.