[MBZ] '88 126 Hesitation Problems and Intermittent Hard Start

[Mark E. Peneguy]

Thanks for the advice on the idle/hesitation issue.  I will look into 
both parts and see if one or both are defective.  One of the things I 
like best about the way Mercedes drive is how smoothly the engine runs, 
even after 212,000 miles, when it has its parts working correctly.  I 
have become spoiled and want to continue to enjoy that smooth operation.

Mark
__________________
Mark E. Peneguy
420SEL
New Orleans
peneguymbz at cox.net

Kaleb C. Striplin wrote:

> Sounds like the throttle position sensor to me on the hesitation.  As 
> for the idle deal, sounds like you are talking about the idle air valve 
> that you had replaced.

and

M. Afzaal Khan wrote:

> Seems most likely the throttle position sensor , Eventually I  tracked  one 
> from a place called Mercedes .com
> mak

> Mark E. Peneguy wrote:
> 
>>> Friends:
>>> 
>>> Recently, I started having a problem with hesitation when I accelerate 
>>> from a dead stop.  Once the car is in motion, everything is smooth, as 
>>> it should be.
>>> 
>>> I don't have a clue as to what may be causing the problem.  I have had a 
>>> few things worked on lately, including a tune-up, with new spark plug 
>>> wires and distributor, cap and rotor, etc., which seems to rule out 
>>> those things as the issues.
>>> 
>>> The only thing that I know made a difference in the idle, and I assumed 
>>> might be part of the hesitation problem, as the hesitation showed up not 
>>> too long afterwards, was a part (wish I could identify it for you) that 
>>> reduced the idle from 1,000 to 1,100 rpm at idle in park, to 550-600 rpm 
>>> at idle in park.  This part plugs in just under the air cleaner housing 
>>> in the front, top part of the engine, if that helps identify what it 
>>> might be.  The engine idles smoothly when in park, neutral or in gear 
>>> (runs about 450 rpm in gear at a stop and there is no "tremble").
>>> 
>>> My second problem is an intermittent hard starting problem (the starter 
>>> was replaced not too long ago and the problem just manifested itself). 
>>> Sometimes, I turn the key and it starts right up, like it always used 
>>> to.  Now, though, if it doesn't start immediately, I turn the key and it 
>>> cranks for a few seconds before it finally starts.  The last time that 
>>> happened, I saw smoke come out from the rear of the car (couldn't tell 
>>> what color, due to the ambient light).  That was the first time I've 
>>> ever noticed smoke come from the tailpipe in the 13 years I've owned the 
>>> car.
>>> 
>>> My trusted mechanic closed shop and is leaving the N.O. area since 
>>> Katrina.  So, I will be trying out a new mechanic to have this resolved 
>>> (wish I was mechanically inclined!).  I would like to have an idea of 
>>> what I may be looking at before I go to a new guy.
>>> 
>>> Any thoughts any of you may have shall be greatly appreciated.
>>> 
>>> Thanks in advance.
>>> 
>>> Mark