Run away 240D engine, very scary! - Page 2 - PeachParts Mercedes-Benz Forum

#16 03-09-2004, 03:42 PM

Quote:

Originally posted by Ken300D
You'll get more of a mess of diesel fuel because the fuel pump will still be able to pump full through the spin-on filter. But the engine should stop sooner.

1/4 gallon of fuel on the floor, saved engine....
clean floor, dead engine...

If that's what it takes to save the engine, I would be happy to mop up $0.75 in fuel.

Fisherman · #17 03-09-2004, 06:20 PM

I changed over several parts on my IP from a used unit and you know I never even noticed a notch in the rack arm...

When I took the parts off the other IP I tried to be really slow and careful to notice how all the parts were fitted and you know it never even occured to me that there was a notch on that arm. I just slid mine in till it made contact with the back side fo the arm and then pulled it to make sure it had ahold of it before I bolted it on.

Mine's been this way for almost a year and seems to be correct...

I think you are fine with the installation. If you notice, these racks seem to go to full fuel delivery with minor pedal movement (or at least that's the way it seems to me) so just that 1/4 of an inch that you give up by fitting it into a notch in the arm would be enough to supply a lot of fuel. On my 240 it runs at full fuel most of the time...

Congrats on saving the motor!

#18 03-09-2004, 08:07 PM

I guess I was picturing someone with a big set of bolt cutters going after the fuel injector lines. That may work, but with these stories I am so thankful I have not been there to try it.
Not a bad idea to keep it up front. It has already saved one engine.

coachgeo · #19 03-10-2004, 12:07 AM

hmmmmm.... Im curious about the springs. Try a temporary additional spring there and see if it solves your problem.

As to run away. Have you ever had a air leak in a fuel line. It really kills the power. So maybe the cut fuel line to the IP has its merrit. The thing starts sucking air into the IP along with fuel. Fuel air ratio is screwed.. car dies. hmmmmmm.

79-240d-project · #20 03-10-2004, 12:11 AM

I know one thing, if I ever need to do any work on the 240 that could result in a run away the air cleaner is going to be off and the phone book will be close at hand. No if ands or buts about it. The phone book over the air intake - engine dies.

Alastair · #21 03-10-2004, 08:11 AM

if you cut the plastic line from lift pump tp main filter, the motor will stop pretty fast, The pressure here is normally at around 25 psi, which pressurises the fuel gallery in the pump.

Douglas Broome · #22 04-06-2005, 12:32 PM

I have read through this thread and the others about this subject. I also replaced the shutoff gizmo on a 240D successfully. I am alert to the cautions about a runaway engine.

In my current situation the car is taking a long time to shut off. The problem is worsening. The manual stop kills the engine quickly, so it is OK. The rest of the vacuum lines--to the locks, etc--all work fine and not too slowly. I have a clear filter in the vacuum line connected to the shutoff, and it shows no oil. There is a second clear filter in the locking system line, and it too is clear. I have to conclude that there are no oil leaks into the vacuum lines from the vacuum pump or the shutoff diaphragm.

Might the shutoff gizmo have failed without letting oil into the vacuum line?

Is there some other gizmo attached to the ignition switch that could be the culprit? What is it? Can it be reached without removing the entire ignition switch assemply?

The Haynes manual mentions a fuel shutoff solenoid. What is that?

Thanks.

Eskimo · #23 04-06-2005, 01:33 PM

Quote:

Originally Posted by Douglas Broome

In my current situation the car is taking a long time to shut off. The problem is worsening. The manual stop kills the engine quickly, so it is OK. The rest of the vacuum lines--to the locks, etc--all work fine and not too slowly. I have a clear filter in the vacuum line connected to the shutoff, and it shows no oil. There is a second clear filter in the locking system line, and it too is clear. I have to conclude that there are no oil leaks into the vacuum lines from the vacuum pump or the shutoff diaphragm.

Have you tried actuating the shutoff (with the engine off) using a Mitivac, as Larry Bible describes, to see the stop lever move? Then waiting to see how quickly, if at all, the pressure on the Mitivac gauge rises?

Added 4/17/05 - I tried this myself on my 300D (has an '82 or '83 engine) today. It shut off fine with the Mitivac, and held vacuum just fine as well. I should correct myself, however, by stating that there was nothing external to see when this happened - stop lever and associated linkage remained just as they were.

mplafleur · #24 04-06-2005, 02:17 PM

My SD has started taking 5-10 seconds (or more) to shut down. I removed the vacuum line at the rubber connector at the shutoff valve and noticed oil. Since it is under vacuum, the ONLY place oil could come from is the IP. Therefore there is a leak.

I am ordering the shutoff valve today.

Douglas Broome · #25 04-07-2005, 08:20 AM

Yes. With the engine off I fit a Mityvac-type (actually Sears) vacuum pump to the orifice facing upwards from the shutoff diaphragm rounnd case. This was after removing the tube normally there, the tube that also had the clear filter which, as I mentioned, showed no oil. I verified ahead of time that the Sears pump worked properly and did not leak down.

Result: the pump would not register (draw) any vacuum at all, let alone get enough to leak down quickly. So, with the engine stopped the thing does not work. Is this an accurate test? If so, it reveals that the shutoff gizmo is the culprit. If that is the case, then I am very fortunate that it failed without leaking engine oil into the protective filter and possibly further into the vacuum lines.

Or must I temporarily connect the tube from the shutoff directly to the vacuum line from the vacuum pump while the engine is running to see if that will activate the shutoff gizmo?

Should I be able to stop the engine with the Sears vacuum pump?

Thanks all.

whunter · #26 04-07-2005, 01:31 PM

Quote:

Originally Posted by 79-240d-project

Thank you know who for being paranoid.

You are welcome.

Stevo · #27 04-07-2005, 01:31 PM

Heres a long shot, but I gota ask...Are you sure you have the right replacement switch? The one on my Euro 240 went out and I had one stashed away. The little arm was a different length in the Euro switch however, cant remember which way but it did fit into the IP.

Eskimo · #28 04-07-2005, 01:53 PM

Quote:

Originally Posted by Douglas Broome

Yes. With the engine off I fit a Mityvac-type (actually Sears) vacuum pump to the orifice facing upwards from the shutoff diaphragm rounnd case. This was after removing the tube normally there, the tube that also had the clear filter which, as I mentioned, showed no oil. I verified ahead of time that the Sears pump worked properly and did not leak down.

Result: the pump would not register (draw) any vacuum at all, let alone get enough to leak down quickly. So, with the engine stopped the thing does not work. Is this an accurate test? If so, it reveals that the shutoff gizmo is the culprit. If that is the case, then I am very fortunate that it failed without leaking engine oil into the protective filter and possibly further into the vacuum lines.

I think you're going about this the right way. You really should be able to pull the stop lever down with a Mityvac and have it stay down for a significant period of time if everything (diaphragm, rubber connectors, etc.) is tight.

Your hand pump can produce a vacuum plenty good enough for this. What it doesn't have (that your car's vacuum pump may have) is the "pumping speed" to overwhelm a particular size of leak.

Added 4/17/05 - See my addition to my earlier post in this thread. I was wrong about the stop lever; mine doesn't move when shutting off the IP by using a Mitivac.

boxscar · #29 04-07-2005, 03:48 PM

what about a runaway due to oil from the crankcase? will you know which it is that is "fueling" the runaway?
in other words, if the engine is running away by sucking crankcase oil, cutting the fuel line will do no good. putting a phone book on the intake will. and you won't have to replace the fuel line.
just my dos centavos...
roberto

Douglas Broome · #30 04-07-2005, 04:01 PM

I have made progress. I have determined that the Sears hand vacuum will not activate the shutoff gizmo and stop the engine. I know also that the hand pump is OK as I tested it with my finger. I removed the vacuum hose normally connected to the shutoff gizmo and, with the engine running, connected the other end to one of the tees coming off the vacuum line from the vacuum pump on the engine to the brake booster. Having tested that orifice with my finger with the engine running, I knew vacuum was present there. Result: the engine stopped immediately. I did this twice and again twice tried with the hand vacuum pump. Same thing every time: stopped using engine vacuum; did not stop using hand pump. In fact, the hand pump would not "pull" any vacuum when the engine was running. I have to conclude that the engine vacuum is much greater that the capacity of the hand pump.

Then I traced the problem to the vacuum lines on the ignition switch. The brown-with-blue stripe vacuum line goes between the ignition switch and the shutoff gizmo. It should get vacuum when the ignition key is turned off. In my case that is not happening. There are no check vales under the dash on either the solid brown or brown-with-blue stripe line, so that is not the problem. Clearly the problem is with the ignition switch. Question: is there some vacuum-related part inside the ignition switch that is replaceable? Or must I simply replace the whole thing, steering lock and all?

Thanks for your help.