You are going lean under acceleration, this is what causes the power loss.

There are many ways this can happen, from a bad vac leak (idle control valve hoses in particular, or a loose booster vac line) to a bad fuel distributor or air flow "pot" that senses throttle opening.

The airflow venturi is what you see in the intake when you take the air filter housing cover off. Gently press the disk in the center down (engine off) and make sure it move smoothly. It's likely filty, carefully wipe all the dirt off the hole it fits in (the venturi) with a cloth wet with solvent. If it sticks or moves roughly, you have a fuel distributor problem, most likely a scored plunger.

If the flap moves properly and you still have trouble after cleaning it, you need to check the air/fuel mixture with a VOM meter that reads duty cycle. A milliamp meter is also useful, although not required.

Hook the meter up with the black lead in hole #2 on the diagnostics connetor (the round one with a screw on cover on the fender) and the red lead in #3. This should read either 50 or 70% with the key on and engine not running, then 50% until the engine warms up. As the engine (and oxygen sensor) heat up, the reading should start to change. It must be 50% or a bit higher (sometimes you need to set it around 40% to get to get good throttle repsonse) and it MUST constantly change up and down. If it swings way high and stays there, you have a vac leak that is allowing too much air in for the feedback system to compensate for.

The adjustment is by inserting a 3mm allen wrench down the little "tower" on the intake manifold (there is a hole in the air filter housing to allow access with the filter in place) and pushing down to engage the actual screw. You can miss the 3mm allen hole, so be careful, please!. The screw fitting can then be turned SLOWLY to change the mixture. Takes about 20 sec to stabilize after adjustments, so go slow.

If the mixture cannot be adjusted, you have other problems.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Hey Guys,
Good news. I think Haasmans' suggestion worked. I bled the fuel distributor and some rusty crud came out. I took for a test run and it didn't seem to do much but driving today it was dramatically beter. I also wiggled the connectors for the sensors on top of the engine, but I think it was most likely the bleeding. My only question with this is why would it work? There is a fuel filter on the system, and wouldn't the crud just get pushed against the fuel injecter inlet?

Rkreuzer, what is a vom meter? Is that a voltmeter, or something else?

Jamie, I would highly recommend bleeding your fuel distributor. My car did exactly what yours was doing.

Mike

Beleive me, it surprised me as well.

Now, do it again! You might still have a bit of crud still in the system.

I don't know why it accumulates there but it does. I got this tip from a Benz dealership tech who said he tjey often will do this on older cars. The crud prevents enough fuel volume delivery under loads.

Haasman

__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)

VOM = Volt/Ohm meter.

__________________
2007 C 230 Sport.

I have done it before. But I need to do it again since I had all the injectors out and engine all apart. I replaced the injectors last night. Same old crap. I got a new fuel filter even though mine is only a year old and has less than 10,000 miles of driving on it. I will do that today at lunch and bleed the lines and all. Could it be a bad EHA or mis-adjusted for me? I am wondering.

__________________
~Jamie
_________________
2003 Pewter C230K SC C1, C4, C5, C7, heated seats, CD Changer, and 6 Speed. ContiExtremes on the C7's.

1986 190E 2.3 Black, Auto, Mods to come soon.....

Clogged downpipes between the header and the cat from stuff I thought I got out but apparantly not. Runs better than it ever has since I owned it now. Exhaust leaks now at the header because the damn bolts are just the right leangth so I can not get them back on, well one on each pipe. Get longer bolts today and fix that leak. But all is well and other than being a little louder it is running and accelerates great now. Like I said better than it ever has since I owned it. The cat actually was fine, I could actually blow right through it and feel it on the other side with what seemed like not restriction at all. It looks like someone before replaced it with an aftermarket one and still looked damn good inside.

__________________
~Jamie
_________________
2003 Pewter C230K SC C1, C4, C5, C7, heated seats, CD Changer, and 6 Speed. ContiExtremes on the C7's.

1986 190E 2.3 Black, Auto, Mods to come soon.....

Bolted all up now. Car runs great, it accelerates better, idles smoother, shifts are no longer hard at WOT like they used to be. It is like a new car to me now! Finally after 1 and a half years it runs like it should. If only I had driven another one to compare! Well I will fill her up now and see what improvements in gas mileage I get. Used to get about 18MPR or less. SO anything over 20MPG will make me happy.

__________________
~Jamie
_________________
2003 Pewter C230K SC C1, C4, C5, C7, heated seats, CD Changer, and 6 Speed. ContiExtremes on the C7's.

1986 190E 2.3 Black, Auto, Mods to come soon.....

Hey Jamie,
Try using dielectric grease on all your relay's. Especially fuel and OVP. Made a huge difference for me. I also adjusted EHA, richen fuel mixture, and replaced all vacuum lines.

Mike