I have a 1989 190E 2.6. The car hesitates a lot when I'm driving in the city. It runs fine when it finally opens up on the highway. When pushing down on the gas pedal it seems like I'm pushing air. The car losses a lot of power then pickups up again. The problem comes and goes. The biggest problem is when I'm entering the on-ramp of the highway the car won't go faster than 40 mph for a least one mile then it kicks in and is fine the rest on the ride on the highway until I get off then the hesitation starts again (intermittingly). One mechanic had me change the plugs, distributor cap, wiring, and air flow meter. The dealer couldn't find the problem. They had the car for two weeks. They said they test the fuel pressure, back pressure and that the O2 sensor and coolant sensor were borderline, but believed to be okay. Any help would be appreciated!!

It's scary to enter the highway and go on with 40mph for 1 mile.

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1996 E320 since 1/16/08, 171K miles as of Feb 2011

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1989 300CE - R.I.P. Dec 29 2007
Other MBs (sold): 1992 300E-24 - 1979 350SLC - 1984 230E - 1990 300CE

Does the engine have any leaks or anything? Have you checked the relays (FPR, OVP)? I also wonder if perhaps it pertains to the coil pack. I have similar problems on my 87 300E. Just like you I have changed a lot of electrical components and still there is hesitation and power loss on occasion. If you do come up with the answer, be sure to let us all know as this has come up in some shape or form on the board before (with no real resolution that I have seen)

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87 300E
202k on the clock

Auto or manual trans?? Also where are you located? A good way to rule out excessive back pressure is to undo the exhaust at the manifold and remove if possible and run open headers(loud as crap i know) and see if the problem goes away or still present. If present wondering if it may be the torque converter.

Again, from reading many of the similar issues on this board, it is clear that coils go intermittant in this time frame on this engine. If not now, then soon. Change the coil as a matter of course, and see what happens. You will not hurt the engine by giving it a new coil.

I changed the OVP and FRP myself a few months ago.

Here is the paperwork I got back:
Replaced wires
Replaced plugs
Replaced dist cap
Replaced rotar
Replaced air flow meter (adjusted potentiometer)
Tested Fuel Pressure (system 80 psi, L/chamber 75 psi
Tested EHA current 20 ma key-on, 2-5 ma @idle, fluctuates w/accel-decel
Tested Lambda Control - good occilates
Tested Temp Sensor - 2.94 52@ 70F
Tested Fuel Volume - Good
Tested Fuel Sample - Good
Tested Both Fuel Pumps - Running
Tested Exhaust Back Pressure - OPSI @idle & 3000RPM
Tested Temp Sensor - Good
Tested O2 Sendor - Good, but is lazy EHA

Didn't check Fuel distributor or for vacuum leaks.

Hi,
Change out the coil. I had the same problems with my '87 300E. My mechanic tried all sorts of things over a three month period but to no avail (he didn't charge either). Finally mentioned problem to my son who owns a Passat. Same thing happened to him. It was the coil. Ran fine at high speed but was flaky at low speeds. Go figure.
Anziani

'87 300E 200K
'95 E420 110K

they checked the coil, said it was fine.

The same thing happened again this morning. I start the car and need to drive about 10 blocks to get on to the highway enterance (alls fine). I ALWAYS catch the same light right before I enter the highway, when the light changes it then starts to happen the car struggles to reach 50mph when I'm entering the highway and when it does reach 50mph it then starts to lose power. (I think I'm going up hill). Then drops to about 20-30mph and I have the pedal to the metal. This continues for about 1-2 miles then it starts to pickup, then it's fine for the rest of the highway ride.

cheapest next move- try the fuel filter...

__________________

Timothy Evans
TimEvans35@gmail.com
CELL 310 990 6780


1985 380 SL
2010 CL 6.3 AMG
*2009 CL 550 Sport 4matic
New addition-1984 380 SE
Newest Edition 1986 300E AMG