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  #1  
Old 11-06-2002, 08:30 PM
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Location: Toronto, Canada
Posts: 700
85 190E 8vlv Hesitation

I have a problem I have been trying to fix for quite a bit now. I bought the car in April 2002, with a new engine. Car has 250K km on it, and engine about half that.

My problem is that the car hesitates as soon as it warms up. It will even sometimes miss ( think I hear a thump from the engine) when I accelerate hard and it only does this in the 1500-2000rpm, anything above 2000 is solid as steel.


I went through the test procedures outlined in the manual for all the electrical parts and my tests are not very conclusive.

Here is what I gathered so far
EHA current is fine on start up, once the car warms up, it will drop to 0mA when I come to a stop and the car will hesitate until the current to the EHA jumps up for about a second or two. I think this might give a good idea to someone who knows these cars as to what the cluprit is.

When the car is really hot, and in idle, the current in the EHA will jump to 8mA and then the car takes off like it should, no hesitation, I think this is how it's supposed to be.

I pulled the spark plugs and an examination shows that the engine is running rich, lots of carbon deposit on new platinum plugs, I heard these are bad for your car.

As I was going through the test procedures in the manual I came to the MAF (Mass air flor sensor) and Discovered that the Resistance on it is not in the right range, 0.98Kohm to 3Kohm as opposed to 3.2-5.2 Kohm as the manul states. I now have a multimeter hooked up to pin #1 and #3 and I see 18V flowing in idle and current dropping down to 10V around 3000rpm. I don't know if this is it but I think it should be corrected either way.

Having tested all other electical parts, the only other part not working right is the barmoteric sensor which I get no signal from at all, I have yet to re-test it for some kind of results.

Post enrichement of mixture checks out to be correct and the car starts up every time with 0 problems.

Hesitation is sometimes sever sometimes not so sever.

The current in the EHA sometimes jumps up right away, sometimes not at all until I reach 2000rpm and then it slowly goes up.

When engien is cold the current in the EHA jumps up very quickly.

I have a few questions. What should be the current in pin #1 and #3 in the MAF? Should I check this any other way?

And of course, what else besides a fuel pressure test can I do to find out what could be causing this???

I'm a bit stumped right now since I was quite sure it was the MAF, but the readings from it are very nice and never erratic, but I can't cofirm if they are our of range or not, if so I can just put a resistor there to get them to the right value, I dont' want to replace a sensor that works since this one is very expencive.

Any other suggestions are welcomed.

Thanks everyone, this forum is great.

xp190
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  #2  
Old 11-10-2002, 01:30 PM
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You've done plugs, leads and rotor I presume?

later
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190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg
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  #3  
Old 11-19-2002, 11:03 PM
psteinke
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I have similar issue, but mine has the problem ALL THE TIME. No power. Max speed 60 mph.

I ALWAYS have 0mA into the eha, but 8mA is supposed to be the midrange for the early 190's. Midrange is equal to a perfect air fuel mixture, <8mA means the eha is leaning out the mixture I think and > 8mA means the eha is richening your mixture.

In later year 190's, the midrange went to 0mA, then plus and minus from there.

One thing I noticed is that the oxygen sensor input to the computer is shorted to ground on mine. I havent gotten a new computer, but senor output is 0.9V (rich) until I plug the sensor into the computer, then it goes to 0V.! (0.5V is normal oxy sensor output and 0.2V is lean). If you can watch the oxygen senesor output while driving and it correlates the eha output being bad or good, this could be it. (i.e. an intermittent short at the oxy sensor input to the computer.)

I am trying to find a cheap eha valve. I heard they tend to go out on these cars.


Please let me know what you find on this because I probably have the same problem.

Paul
steipau@iit.edu
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  #4  
Old 12-10-2002, 06:02 PM
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Join Date: Apr 2002
Location: NW suburb of Chicago
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i get the same thump and seeming lack of power from my '84 2.3l i have been assuming it was the tranny or something tranny related causing this
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190e 2.3L
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  #5  
Old 12-10-2002, 08:33 PM
psteinke
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try this, maybe you wont believe it

Try purging the junk out of the lines between the fuel distributor and the fuel injectors by removing the injectors and cranking the engine a little. (Don't let fuel catch on fire though). Also try tapping the injectors on a block of wood so that any junk inside them will come out backwards. I have been thinking that the problem was a clogged fuel filter. I was absolutely convinced of this when I bought the car. But clogged injectors make it act just exactly like a clogged fuel filter, right? This is the same principle. I have two black plugs and two clean plugs. Probably the black plugs come from bad injectors dumping raw gas into the cylinder and these cylinders will therefore lack power bigtime, though not enough to make it seem like a missing cylinder. Although I do get a missing cylinder for 2 minutes when temp is below freezing. It all adds up.

Check out this other thread. I put a double shot of fuel infoector cleaner in one tank and got 5mph improvement on the top end.


low power on acceleration
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  #6  
Old 12-10-2002, 08:57 PM
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ive hit about 90 and was still accelerating albeit slowly with the tach reading 4500, any ideas what the top end on my car is and where does the engine start getting into the danger area in terms of rpm
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  #7  
Old 12-11-2002, 11:54 AM
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Location: England
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My 2.0 accelerates well up until 110, from there a little more encouragement is needed to gain speed. But it has a vacuum leak and I've severly retarded the ignition because of it, so it's certainly down on power.
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190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg
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  #8  
Old 12-12-2002, 01:38 AM
psteinke
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replaced one injector

I replaced injector on cylinder close to firewall (#4). This one had a plug that was always black, just like the cylinder farthest away from firewall (#1). The middle 2 cylinders plugs looked perfect. Anyway, I get no benefit from replacing this injector. Maybe its the cylinder #1 that is causing lack of power. But if this much lack of power was all coming from one cylinder, it would feel like a missing cylinder, right? So it must be something else. There is not enough pressure due to a failed eha. This seems more likely to be it now. But when I measure the pressure out of clyinder #2 for example, I get 78psi. And when I hooked up injector from #3 onto the fuel distributor output for #4, the spray pattern looked good. But spray pattern from #4 injector hooked up to #4 output had drops at low rpm and I think a poor spray pattern at higher rpm. So that was pretty sure to be a bad injector. Maybe the plug is still fouled because of the way the previous injector was running? No then I would get a definite miss.

I expected about 25% improvement. I got none. This makes me seriously doubt it is injectors.

Also, since I cannot detect a miss after it warms up, I think it is not all coming from one cylinder, the problem is distributed among all cylinders.

I could not get any junk to come out of the tubes leading to the injectors or the injectors themselves (tapping them upside down). But then I only tried two injectors.

Any thoughts, guys?

Thanks, Paul
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  #9  
Old 12-12-2002, 02:05 AM
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What plugs are being used by everyone?

I installed platinum quads in my '91 300E thing nothing but the best for this baby .... and then I started having all kinds of weird starting and running problems.

I found one of the spark plug wires to be bad and replaced it, I then pulled the platinums and installed the standard recommended (inexpensive) single electrode plugs (per the owner's manual) the car has run exceptionally well since.
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'95 E320 Wagon-Went to Ex
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'91 300E-Went to Ex
'65 911 Coupe (#302580)
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  #10  
Old 12-12-2002, 02:45 PM
jfujimoto
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haasman,

Bosch H8DC in my 190E.
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  #11  
Old 12-12-2002, 02:49 PM
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Here is a link regarding these plugs .... Gilly has spoken!

190E plugs
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'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
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  #12  
Old 12-12-2002, 02:54 PM
jfujimoto
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haasman,

"O"-kay. Thanks for the information!
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  #13  
Old 12-29-2002, 08:25 PM
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Join Date: Oct 2002
Location: Toronto, Canada
Posts: 700
My new distributor cap and rotor arm are on the way along with H8D plugs instead of platinums. I cleaned up my injectors and lines but that didn't change anything, idle speed improved a LOT in stability, but the car still lacks power.

Now that I saved up some money, if the new parts which should be here tomorrow do not make a difference I might be replacing the fuel pump, fuel pump relay since it looks fired and does not shut off my pump when ignition is on, and a new OVP.

hopefully one of these things will cure this problem, it's very annoying.

xp
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  #14  
Old 12-29-2002, 08:54 PM
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You know, it was something you said:

Quote:
Also, since I cannot detect a miss after it warms up, I think it is not all coming from one cylinder, the problem is distributed among all cylinders.
What about checking into the cold start circuit. I am wondering if you have enrichment running all the time?

Just a thought ....

Haasman
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'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
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  #15  
Old 12-30-2002, 07:50 PM
psteinke
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enrichment circuit always running

No, my enrichment circuit is not always running because I can disconnect the cold start injector and the eha completely and I get no improvement.

I am very interested to see if the H8D plugs make a difference. I hope xp190 posts after replacing them.

BTW, xp190, does your car lack power all the time or does it just hesitate when the eha current is low? Mine lacks power all the time and even manually adjusting the eha current will not make it run better. I can make it run worse, though with a large positive current. So I am beginning to think the problem is in my fuel distributor, or maybe it is in one of the fuel injectors that I did not replace, or maybe my intake valves are leaking some compression back toward the intake manifold, therefore causing the next intake stroke to suck already furned fuel into the chamber.??

Also, there are 4 screws on the bottom of the fuel distributor that let you get more power even if your eha has 0 current all the time. These adjust default air fuel mixture. I haven't done it but i know somwone who has.

Paul
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