nashvegas

Hi everyone - 1995 e320 that's new to me (3 weeks).

Background = wiring harness + head gasket replaced in past few years. Car in perfect shape. Sold it to me b/c of this issue and they said it needed a new throttle body. I took the throttle body off, and sure enough the wiring was toast. I spent this week (at night) rewiring it, which was hilarious test of my marraige given that I did it at dining room table.

Anyways, tonight, put the car back together. Started right up. I was in shock as I was giving myself about a 20% chance of not screwing up wiring or soldering and quite honestly I was expecting the car not to start and I'd mentally prepped myself to buy the new 1500 throttle body..

Here's the crazy thing. Car started right up but has the EXACT SAME SYMPTOMS. Basically, it starts up perfectly. Idles perfectly. if you really granny-like step on gas its perfect, but if you punch it, from about 2000-3000 rpm there is a horrible miss / misfire / hesitation/ chugging that sometimes even results in what sounds like an intake backfire.

So -- maybe it wasn't the throttle body. Sure of that now, but even still, the wiring was completely crap so it was good that I rewired it, I guess. I havent checked plugs, plug wires or coil. Could it be something so simple ? Or could the electronic throttle be bad and this is just what happens/ Other ideas ?

THANKS IN ADVANCE

Glen

Most likely one or more of the coils is going out.

KirkKirkland

Have you figured out the problem? I have 95 E320 Wagon with similar problems; Sluggish but if you mash the peddel to the floor it will go and backfire.

nashvegas

But i think its a bad MAF sensor ! with a code reader i bought on ebay, i found code that indicates the maf is bad. but i havent replaced it yet

dsgn

Yep, a faulty Air Meter. You cannot rev consistently across the band. Vehicle will stall after warm-up. You should have been having rare inconsistent idles that corrects itself momentarily.

Repair is very simple. With the appropriate tools -- should be about 10 minutes at most. In addition to that, verify the plugs are non-resistive non platinum plugs. Copper plugs is all you need. Check your throttle body and clean (if need be). Plugs should be gapped at .32mm.

Check around and ensure no vaccum leakage or blockage.

Engine should be very smooth at idle, burn clean and be eager to be revved.

lsboogy

http://www.benzworld.org/forums/w210...-cleaning.html

I've been cleaning MAF's (100+mm ones - which are expensive even for Benz people - $700 on up) for years with first carb cleaner (makes them short lived, but can revive them), and then contact cleaner (better), and now they make MAF cleaner specifically for cleaning the wire. It works many times, as the part that causes mis-compares/mis-reads is usually the exposed wire. Occasionally, the divider resistors will also go bad, and then you have to replace the thing. But it takes 10 minutes at most, and works about 90% of the time. Might as well give it a shot - quick and dirty.

What damages most MAFs is not oil from oiled filters, but backstreamed gasses - a cam with large overlap tends to kill a MAF quickly, and running 40 degrees of overlap or more is a recipe for cleaning a MAF on regular intervals. But cams like this only seem to exist on touchy Saturday night cruise machines, and do not lend themselves to idling. I'm not sure what the overlap of the cams on MB's are, maybe Marcus can pipe in on this, but they idle too well to have any serious overlap. Most serious street/drag people have MAF programmers in their garage, they work off your laptop and allow you to adjust the thing pretty easily.

GuilhermeRocha

ey guys.. sorry to revive this but might need your help..

My car has the exact same problem (300# 2.8, 50k miles) got new spark plugs, coils, cables, redone wiring harness, ovp is good. alredy on my second MAF sensor and the car has same problem as your's..

At idle rpm drops 1 seconds and get back to idle again.. driving it easy it shows no problems but when I mash the throttle shakes and backfires and after 2-3 seconds (time to gearbox to reduce 1 gear) it goes like a train!

Any help would be great

ciac

just wondering if you ever figured out what happened? seemed to happen to my car as well. there's a bit hesitation when mashed accelerator, sometimes pinging after the car is hot, and at times rough idle under load (AC/uphill). I just cleaned the MAF and it seems to do similar things, though exhaust doesn't smell as bad as if the MAF was removed. The car can rev freely, but can hesitate and dip in RPM a bit while idle. Under load it can stutter, and can misfire if i keep the gas on. Any ideas?

nhmercracer

Is the check engine light on?