E320 Problem Help
 

HAVE a 97 e320.

car had bad idling and running rough.

up to date i have replaced plugs and coil connectors to plugs.
now idles smooth but rough when revving and flooring the car it will hesitate and battle to reach rpm.
it will rev to red line but takes a while getting there.
when i drove it for a while yesterday it felt like it was getting better and would accelerate better.
was unsure of the coils .....i replaced earlier. it made no difference.

the car right now is still rough and wont rev.....no check engine light or any codes.

PLEASE HELP.......NOT SURE WHAT TO DO NEXT :mad:

:D

nobody have any suggestions???

Ok, check the engine harness and look at actual valves for the airflow meter.



Joe

I'm surprised you don't have any codes. Either your experiencing a mis-fire (which would set a code) or you have a mass-air sensor problem of which would set a code too. Do you suppose your fuel filter might be clogged?

My thoughts , also..
Don't assume there are no system monitored faults just cuz there is no CE lamp...[CE lamp is emmisions related fault indicator only.. ]
Have you actually gone into code retrieval and live stream data??

When my engine wiring harness was bad, my car backfired through the intake manifold, misfired, stumbled, etc., and the CE light was never tripped.

HI SUGINAMI....
nice to see you here. you helped me a couple of months ago with a 1994 e 320 i had. that was on another forum.

update...
the car is very bad when cold....snap changes when shifting and wont rev beyond 3000 rpm ..very rough. while driving i would take it out of gear and it will rev to red line but still rough.

after about 3 miles it will start clearing itself...when it is warm it feels good and the gears change smoothly but there is still a bit of roughness when you kickdown and floor it.

i think i have 2 problems that are not related...

1) the vibration i feel on the car thru the steering goes away when i put a trolley jack and jack up the transmission of the car slightly...the vibration goes away. i will replace the transmission mount and also the rubber disc on the propshaft.

2) i saw a post where ARTHUR DALTON explained the closed/open loop cycle that the car goes thru when it is cold on the transmission....

could there be a relation to my problem.

just to confirm there are no codes and check engine light.

About your shifting issue, the car does have an upshift delay valve, that delays the transmission shifting from 2nd gear to 3rd gear, causing your catalytic converter to warm up quickly.

However, this definitely would've tripped a check engine light (code #26), which is a very common occurence on these cars.

About your missing problem, you might have a bad coil wire, or maybe an intermittent connection between one of the coil wires and its supressor end.

YIP SUGIMANI.
I HAVE DONE ALL OF THAT . NEW COPPER PLUGS, COILS AND PLUG CONNECTORS BETWEEN PLUGS AND COILS.....

I would check the plugs again. You might have got a bad plug.

THIS problem is intermitend. some times floor it and power comes on nice and smooth.
other times you pull of and accelerate and the motor will "bog down". you have to back off and accelerate smoothly.
i checked plugs again and all fittings. idles smooth without a miss. if i pull injector wires off 1 by 1 it stumbles... the same with the plug caps.

:mad: :mad: :mad: :mad: PLEASE WHAT COULD CAUSE THIS.

B.T.W if it was a clogged fuel filter would the problem be intermittend???

I still think it's starving for fuel

low fuel pressure, bad fuel press. regulator, clogged fuel filter, etc. etc.

an old friend once told me....if you think it is electric its fuel..

WILL THE PROBLEM BE INTERMITTEND WITH FUEL STARVATION??

slow throttle response like your describing and missing when accelerating. That's what I would be looking at with no codes. I think it is most certainly fuel

The fuel rail has a pressure test port.
With a gauge , you can test both holding and running pressures,
[ this also test regulator] ,but with your condition, you also want to check Volume...
That is where a filter will fool you....you can still have proper running pressures , but when under a load, volume can be too low for demand....

to add to what Arthur said, I would bet money it's a partially clogged fuel filter

Here is what you are looking for :

At idle, 3.2-3.6 Bar [ bar =14.5psi]

W/vac line to reg disconnected , it should rise to 3.7-4.2

It should hold for 30 min after turned off to no less than 2.5 bar

Volume should be 1 liter in <35 sec.

I would imagine your guy has already done a FP test, but you may want to ask...

I agree with JoeP. have the values checked for the self adaptation and air mass.If you're hitting on all cylinders but slow to rev,probably it's the airmass sensor.On these cars that IS part of starting with the basics.
Paul

I tend to agree with the others that your problem is likely fuel supply related.

However (comma space) I had an intermittent problem very similar to yours, and it ended up being one bad coil wire causing the problem.

Go figure.:mad:

UPDATE....

1) VIBRATION

thanks for all the responses. i have changed the flex disc and the tranny mount.
this definately resolved most of the vibration problems.

2) HESITATION UNDER LOAD.

i have replaced the fuel filter..... no change.
checked fuel pressures...all o.k
(not sure how to check for flow..volume) i guess i have to bridge fuel pump somehow??????

the car still hesitates under full acceleration or when kicking down hard...

how do i check "for self adaptation and air mass for mass flow sensor" do i need special equipment or can i do the check???

your responses are appreciated and it is taking "baby steps" but the car is getting better.....thanks

()

any comments please?
i am desperate to find how to check values as described earlier.
althouhg i replaced the coils and coil connectors i only replaced the other 3 plug leads today......no difference???

Spikes, type multimeter in the search and you will find a lot of usefull information. Also search for Led/sw. For a 97 E320, I am not sure if you can check the various modules, with the information you will find with the above searches.

I would focus on the engine control module, this module controls most of the engine functions, including air fuel mixture for various operating temperatures.

Also, these car have a whole bunch of vaccum line, I would make sure everything is connected.

cant find much help under search.
what causes car to hesitate and not run when under kick down load......:mad:

is there anything else i can check..?:D

:D any one?

have you checked for codes yet? I see no where that you've done this. It would help you and everyone else to better troubleshoot your problem. Aside from gathering any codes that have been tripped we are all guessing from prior experience, and that could end up being very costly for you. It's called the shotgun theory, if you throw enough parts at it you'll probably end up fixing it sooner or later, and that's what you don't want!!

Please either check for codes yourself of have it done at a shop.

Dale is right. You're wasting alot of time throwing parts in that you may not need.Spend some money and have a shop plug in and retrieve complete engine data.You can have a part malfuntion without the check engine light on.Like I mentioned before,my money is on the mass air sensor.
Paul

thanks paul and jetforman.

i was under the impression that once the battery had been disconnected and no check engine light there are NO CODES.

i will get a shop to pull codes.

thanks guys........it is dissapointing when parts are replaced and does not fix the problem:D

I was under the impression that the check engine light will illuminate only if a fault code has been tripped that affects smog emissions. At least it works this way on my car, but it is OBD-I.

update

checked codes....nothing....
checked adaption value for m.a.s -----1.21

I am told that the engine light should trigger soon as this is not right..

can anybody please confirm if this means mas is bad.

thanks

That adaptation value does not tell you what is causing your lean mixture.

On the W124 HFM-ECM, the adaptation limit is +- 25%. So, at 1.26, the HFM module would store an Adaptation at limit fault code.

The Engine Control Module tries to keep the air/fuel mixture at the optimum level. There are numerous reasons why at times it is unable to do so, eg. Fuel injectors, vacuum leaks, electrical problems, modules etc.

Ignition Analyzer scope can give you an insight into what's going on at each cylinder, also check the adaptation values at different engine speeds. If the adaptation values are worst at idle, you probably have a vacuum problem. If it is a fuel related problem, it will probably get worse at higher engine speeds.

I suggest getting alldatadiy and familiarize yourself with the various systems of your car. Then develop theories. Based on these theories, you can design experiments and checks to collect data. Then use this data to investigate further in the direction you feel the data is pointing you, and it may lead you the cause of the problem. Sometimes thou, you may have to start eliminating various causes, including replacing parts with good known parts to see if that fixes the problem.

Hope that helps.

thank you for your response.:)

UPDATE.

as can be seen from my posts i had no tell tale signs of problems..ie. check engine light etc.

i had replaced a whole lot of parts and car was "breaking up" under load.

i reversed all parts replaced and only replaced the M.A.S...

the car drives as new ....no problems:D

LOOKS LIKE THE M.A.S IS THE MAJOR PROBLEM ON THESE CARS...CHECK IT OUT FIRST.

B.T.W: anybody want to buy 3 new coils still in box and set of 3 plug wires AT HALF THE PRICE.....:cool:

PAUL YOU WERE RIGHT ON THE MONEY...:D