'99 e300d: high rev at shutdown + CEL - PeachParts Mercedes-Benz Forum

notfarnow · #1 04-08-2008, 06:14 PM

OK, at first I thought this was related to my veggie conversion, now I'm not so sure.

Intermittant issue:

When shutting the engine off, it idles HIGH for 3-4 seconds, then shuts off. When I restart, I get the CEL . The CEL stays on for 2-3 days.

When I get this "high idle" at shutdown, it takes a bit more cranking to get it started next time around. Normally just starts at the flick of the key, but in this scenario it takes 4-5 seconds of cranking.

There are NO other symptoms. Car runs like a top... perfect idle, great power, no air bubbles in the fuel lines. I'm going to get the code read tomorrow.

One observation: On diesel, I'm showing ~12-15 Hg of vacuum at the filter, compared to ~5-10 on veggie. Could high vacuum from an old filter trigger the CEL?

Thanks!

Parrot of Doom · #2 04-08-2008, 06:29 PM

Two things come to mind.

1) Faulty fuel shutoff valve (black valve, 3 fuel lines, side of injector pump)

2) Oil leak leading to runaway diesel.

The shutoff valve is electrical, not vacuum.

TMAllison · #3 04-08-2008, 06:38 PM

I would look for a leak at the SOV oring first.

PO215 clears itself if doesnt re-occur after 3 cold/hot run cycles.

Can't help on the pressure issue.

notfarnow · #4 04-08-2008, 07:02 PM

Quote:

Originally Posted by Parrot of Doom

Two things come to mind.

1) Faulty fuel shutoff valve (black valve, 3 fuel lines, side of injector pump)

2) Oil leak leading to runaway diesel.

The shutoff valve is electrical, not vacuum.

So is the brief "high idle" a symptom of a faulty SOV? I'm sure I read about that at some point, but can't seem to find it now.

The vacuum readings I was referring to were actual vacuum measured in the fuel lines, to monitor the fuel filters.

Quote:

Originally Posted by TMAllison

I would look for a leak at the SOV oring first.

PO215 clears itself if doesnt re-occur after 3 cold/hot run cycles.

Can't help on the pressure issue.

I looked around the SOV, but couldn't see a leak. Would it usually drip right below?

Thanks!

notfarnow · #5 04-08-2008, 07:05 PM

ahhhh

http://www.peachparts.com/shopforum/showthread.php?p=1802704

Quote:

Originally Posted by charlie a.

The rev always goes up before the engine turns off. After then the check engine electronics light comes on. I also smell diesel fuel in the engine compartment when I turn off the engine after driving it for a while but I can't find any leak. Any ideas?

notfarnow · #6 04-09-2008, 05:15 PM

Quote:

Originally Posted by TMAllison

I would look for a leak at the SOV oring first.

PO215 clears itself if doesnt re-occur after 3 cold/hot run cycles.

Had the code read this afternoon, it was indeed po215.

I've got an o-ring in the garage... what are the chances that will fix it, vs having to get a new SOV altogether?

Has anyone else had the short "high idle" while shutting down, and fixed it with the o-ring alone?

TMAllison · #7 04-09-2008, 07:20 PM

Am assuming you mean a short (1-2 second) increase in RPM after the key is turned before engine shuts down.

A deterioated oring at the SOV caused that to occur on mine. New oring solved problem.

I def say the oring is the first step.

Spray the torx bolts with carb or brake cleaner first so the bit gets seated well; dirty bolt heads has caused some folks to strip them.

You can do the job from the top in 10-15 minutes if you pull the windsheild washer bottle and get it out of your way. Disconnet the fuel lines up top and take the SOV and lines out as a unit.

If the oring doesnt fix it the second step would be to replace the K40 relay unless it is known to be new. Step three would be to r & r the SOV.

notfarnow · #8 04-09-2008, 07:48 PM

Great stuff, thanks a ton for your help! I'll report back when I start working on it.

reinerh · #9 04-10-2008, 09:36 AM

Quote:

Originally Posted by TMAllison

Am assuming you mean a short (1-2 second) increase in RPM after the key is turned before engine shuts down.

A deterioated oring at the SOV caused that to occur on mine. New oring solved problem.

I def say the oring is the first step.

Spray the torx bolts with carb or brake cleaner first so the bit gets seated well; dirty bolt heads has caused some folks to strip them.

You can do the job from the top in 10-15 minutes if you pull the windsheild washer bottle and get it out of your way. Disconnet the fuel lines up top and take the SOV and lines out as a unit.

If the oring doesnt fix it the second step would be to replace the K40 relay unless it is known to be new. Step three would be to r & r the SOV.

can anybody please enlighten me what the SOV is???

i dont have any issues just would like to know what that is.

greets

reiner

notfarnow · #10 04-10-2008, 10:36 AM

It's the electronic shutoff valve on the side of the injection pump. On the e300d, it's not a simple vacuum operated valve like on the earlier cars. It's an an electric valve that reverses the flow of fuel to/from the IP, shutting down the engine.

reinerh · #11 04-10-2008, 11:55 AM

Quote:

Originally Posted by notfarnow

It's the electronic shutoff valve on the side of the injection pump. On the e300d, it's not a simple vacuum operated valve like on the earlier cars. It's an an electric valve that reverses the flow of fuel to/from the IP, shutting down the engine.

oh gee, i must have early alzheimers that i could not think of that.

thx much for enlightening me

notfarnow · #12 04-15-2008, 10:54 AM

Update

Changed the o-ring last night

Typically, the SOV bolts were nasty. After a while, I was able to get the rear one out. But that front one was made of fudge and just came apart. I drilled it a bit and used an easy-out.

Once it was off, I could see that it had been weeping a bit, and the o-ring was very "square". I put it back together with a viton o-ring and used new bolts.

I also replumbed the fuel flow through the filters, SOV, lift pump and fuel valve. It's hard to say which "procedure" cured the problem... I would have liked to do one at a time, but I couldn't justify taking it all apart twice.

Either way, the car is working like a top now. The car suts off immediately when I turn the key. And it restarts at the flick of the key... previously it would crank for a second or two. The CEL is still on, but should clear itself within a couple days.

My power is back too. The po215 code must be one that limits boost. I've been going out of my mind, driving like a grampy. I was SO GLAD to get my mojo back.

Thanks again for the great advice!

TMAllison · #13 04-15-2008, 12:39 PM

Glad that worked for you.

The rectangular profile on the SOV oring tells you that it had been in there for a while.