Does The car have any Stored codes..? Check Engine lite on?Do You Have Pressure Gauges on the Engine?Checked with the EHA Unplugged?...Or how about a Blocked/plugged return line?But the Fuel pressure would be Sky High!Is This Only When Warm?
Yes the EHA can Pass enough fuel to make a mess
As It Will Damage the O2 Sensor and Load up the cat

EHA can leak a large amount of fuel certainly enough to be cause your milage to go to 10 mpg.
m

__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)

Thanks yall.
Mark, there are no stored codes in the 89 W124. The fuel pressure is good and the return line is open. Problem is constant, EHA plugged/unplugged, cold/warm and when in open/closed loop. I just replaced the fuel pressure regulator because it was leaking at the vent tube.

Cap'n

Did you solve your bad mileage problem after swapping out the fuel pressure regulator?

Or rather, did you solve the problem at all?

Cheers.

I thought it was going to solve it as the gas mileage seemed to improve the next trip out. But if it got any better it quickly went back to being at least as bad. My regulator was leaking only a slight amout of gas into the tubing. I recall M.B. Doc saying that he lost an engine begause of this once. So apparently they can leak a lot worse than mine was. I have the injectors out of mine right now awaiting replacements. I'll try to post some pics soon of the fuel distributor flow test I did. I just got back from vacation and haven't got 'caught up' yet.

I am having the same problem as you.

Bad mpg (from 420km per tank to 260km) and smokin'!

Problem consistent cold/hot, eha on/off.

Can get a smooth idle but smoking really bad.

If I lean the mixture, smokin' less but idle really crappy (of course).

Also, while checking the fuel pressure regulator (read in a post somewhere that if it leaks fuel it's history), pulled off "vac" hose and broke it!

There is fuel leaking from the regulator anyway and I will replace the "vac" line and breather hoses as they're crappy anyway.

You changed your regulator and it didn't help at all?

I was also looking to do this but it's a 200 dollar part so I want to do some tests before I swap it out.

I have access to my kid brother's 190e (identical year/model) which is currently in good running condition (powerful at 21% duty cycle but lower mpg - 380km per tank) and will swap the part to see if it makes a difference (I doubt it).

I have recently posted my problem and I'm also closely following yours.

I was recently recommended to another Merc techie and hope this guy (he'll be the 3rd) can sort this out for me.Else, I'm on my own!

Best of luck, and I'll inform you as soon as there is a breakthru'.

I got lucky and found a used regulator for $100. The new regulator will come with the rubber tubing intalled. The white tubing is plain nylon vacuum tubing. Inconsistent fuel pressure can cause fuel management problems but I think my problem lies elsewhere. At any rate, if the regulator is leaking ANY gas then it needs replacement.

Arrrggghhhh!!!!

Do you know specifically how the regulator goes bad?

Everyone seems to point out that if it is leaking fuel, it is bad.But I'm interested to know what's going on with the regulator when it leaks fuel.

And the problems it can cause when it is bad.

Anyone?

If it is leaking fuel, it is certainly bad, and should be replaced before it gets worse. BUT, a leaking regulator may cause no other problems. Performance problems would relate to its inability to maintain the correct fuel pressure, which must be tested with a pressure gauge. If fuel is truly leaking out the vent port, then why not replace it anyway, and if that does not solve the running rich issue, then at least you fixed the leak and have eliminated high primary fuel pressure as a likely problem too.

Steve

__________________
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7

I guess that's next.

Tomorrow morning, I will also check for leaky fuel injectors and check the fuel distributor for leaks.

This is frustrating me, but on the other hand, I'm really interested in getting to the root of this problem.

Cheers.

With the engine running, the injectors are fully 'on' almost all the time. Shutdown is only during some decel conditions, and with the engine off. So, leaky injectors are not going to cause your problem. Leaky injector seals will cause a lean-run condition.

Interested in what you find with the fuel distributor. Good luck!

Steve

__________________
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7

Here is a contraption I rigged to test fuel flow. Injectors are removed and fuel distributor is separated from air chamber. After bridging terminals 7 & 8 on relay, I manually depressed the plunger. Fuel flowed freely from lines 1, 3 and 5 but was much less volume in 2, 4 and 6. I removed the fuel lines at the fuel ditributor and lightly depressed the plunger. Nasty fuel came out followed by clean. After reattaching the lines I got what appeared to be equal flow from all the lines. I haven't ordered new injectors yet so I may hook it all back up just for the hell of it to check spray patterns. Injectors aren't hard to replace so if I still need them it's no big deal.

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Cool.

Learn something new here EVERYDAY!

I am thinking of lifting the distributor up with the fuel lines connected after a short engine run and see if there is any fuel dripping. If there is, I guess closer inspection is required.

another view

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