190e running rich with eha on/off.Bad mpg.Help! - Page 4 - PeachParts Mercedes-Benz Forum

#46 09-16-2003, 05:09 AM

Top half.

#47 09-16-2003, 05:09 AM

Bottom half.

#48 09-16-2003, 05:10 AM

Diaphragm.

#49 09-16-2003, 05:10 AM

Taken apart.

#50 09-16-2003, 05:15 AM

I have not taken mine apart.

These photos were from Cap'n Carageous' and Hurshi's (I think) posts.

Meanwhile, with the EHA off, my car runs well when cold but crappy when warm - severe hesitation on acceleration, smoking badly on hard acceleration, surging idle...

What sort of symptoms do you see on your car which is prompting you to take the FD apart?

By the way, the tech who was supposed to fuel pressure test my car simply diagnosed a "bad FD" without even willing to diagnose further!So I haven't got any results...

cc260E · #51 09-16-2003, 05:47 AM

Thanks to all those who have taken these photos, they are very helpfull to see the hardware before opening especially when it is expensive.

The problems I am facing since a few years with my car, which by the way is fantastic, is an erratic loss of power while running which can go up to total switch off, and some times unstable iddle.

I have posted my concern on the post "loss of power while running" with some suggestions and ideas from members.

From the photos you provided I have a confirmation of a possible leak that, if the fuel quantity is big can induce malfuctioning of measurement the air mass flow device.

I expect changing the O-ring on the central cylinder which is moved by the air mass measuring system.

I have been for a long time investigating the way to monitor/measure the fuel pressure on the upper and lower chamber of the FD while running to see if the pressure on the Injector is the cause.

Have you any idea if chaging this O-ring is possible whithout dismounting into part the whole fuel distributor?

I will let you know

stevebfl · #52 09-16-2003, 08:44 AM

Really good photos , I just called my partner in to show them. Actually I really only wanted to show him one; the final one showing the o-ring, as the other pictures are only of general educational value if included in a theoretical discussion of function.

There is no need to ever see the inside for any other reason. Anyone who has gotten one of these back together and had it work surely had a working unit to start with. The chances are at least a hundred to one against reassembling an old unit with old parts and fixing anything. I have taken a number apart for informational purposes and maybe one worked afterwards.

I mention this to be sure that anyone heading this direction to replace the seal or just for fun doesn't think that taking it apart this far is part of the job. I would only disassemble this far once you are sure its bad and are sure you are ready to replace it when it really don't work after reassembly

#53 09-16-2003, 01:22 PM

Looking at the photos and the posts relating to taking the FD apart, I agree with Steve's comments.

In my case, I don't even have the option of taking the FD apart coz none of the little bits (o-rings) are available here.

FDs here are sold as complete units together with the EHA.

If my FD does end up getting replaced and solves my problem, I will keep the old one and take it apart for it's educational value.

I have done the same with my defective fuel pressure regulator, plug cables, fuel pump relay, OVP, etc.

Good to know how the stuff works internally.

My 2 cents.

Cheers.

#54 09-18-2003, 03:04 AM

Still, my problem is wierd...

With EHA off, 1st key/no pedal starts the car immediately when cold!

Don't know if this points to a leaky injector/cold start valve?

Car runs well for 1st 10 minutes or so coz still cold.

When warm, it starts to misbehave.

Severe hesitation on acceleration, surging acceleration when the car does move off the line, smokes badly and does not go beyond 60 - 70 km/h.Mpg is down - 44 litres against 260km!That's like 6km/litre.Leaning out the mixture till it idles rough gets slightly better mileage - 7km/litre but still same symptoms.

All these symptoms are displayed with the EHA DISCONNECTED so I have removed all the electrics/sensors from the equation to simplify (if that's possible) troubleshooting.

I wonder if anyone else has had the same issues?

I believe some people have posted more or less the same symptoms to their problems but I don't remember anyone stating that even with the EHA off, the car starts 1st key/no pedal immediately when cold.

stevebfl · #55 09-18-2003, 07:45 AM

"the car starts 1st key/no pedal immediately when cold"

This does tell us something. It tells us that your basic mixture setting is about ten times what is necessary for closed loop.

If measured with a gas analyser I imagine you are running 3-5% CO. ... all the time!

#56 09-30-2003, 04:51 AM

Stevebfl, cap'n, sbourg and all who have contributed to this thread - the problem has been solved, not suprisingly by swapping out the fuel distributor.

Having "extensively" checked/tested/troubleshooted the car of "most" of it's sensors/switches/pots/etc, I finally went for a FD replacement.

Having run with the EHA off, tested ignition components, replaced a shot fuel pressure regulator, the car was still running super-rich even though the mixture had been leaned to the point where the car could barely idle.

I got a used one at a local wrecker (with an exchange policy if the part is defective) and got it installed on Saturday.

Re-tuned the mixture to around 50% duty cycle by checking X11/pin 3 and went for a test drive...

Wow!The car runs like new!

I topped off the tank and now i'm checking if there is a significant improvement in the fuel mileage (or if I can regain my regular fuel mileage of 440km per tank - if that is at all possible).

Today, having done 235km, the needle is just at the halfway mark so it's looking good!

I have the old distributor and I'm taking it apart.

I noticed a subtle difference betw the "new" one and the "old" one - looking at the new FD from the top, i can see that within each "outlet", there is a small little pin hole inside .

However on the old one, I can only see the pin hole in 3 of the "outlets, the 4th one is blocked by something metallic.

I am taking the old FD apart to see what's up - 8 of the black Torx screws have come off but it will not split open.

Do I have to remove the plunger 19mm (i think) nut before the FD can split between the upper and lower chamber?

This has been and will be a great lesson for me.

Your tips please, guys.

I will post photos shortly.

Cheers.