Gas in oil pan....

[coreydmc]

Can you please give me a few pointers on how to check the plunger? I am checking google and forum but i cannot tell how to check it....

I found this: One of the few maintenance procedures possible is to free the center plunger in case it is frozen in its channel. This will not necessarily fix the problem, but may only change the symptoms. A stuck plunger is typically observed as an air input metering flap that is either frozen in the closed position, or never develops any pressure with the engine running, and the very rich condition mentioned above.

With the fuel distributor removed from the engine, pull on the plunger with needle-nosed pliers. The plunger is VERY hard so this will not damage it. If the plunger does not come out with some effort, STOP and get another fuel distributor. If the plunger does come out, clean it up with solvent, use some cotton swabs to clean out the passage (DO NOT pour solvent into the unit!) and reassemble. CAUTION: dropping the plunger on a concrete floor will damage it and it will no longer move freely in the bore. Be careful!

My air metering flap moves up and down freely. Is it possible to test the air metering plate pressure if the engine wont start? I need to remove the fuel distributor to see if the plunger moves freely correct? Can I see the plunger once the fuel dist is removed?

[coreydmc]

fuel-prim-pressure-reg..jpg

Is the plunger behind the 16mm nut in this picture?

[sdg3205]

fuel-prim-pressure-reg..jpg

Is the plunger behind the 16mm nut in this picture?

No, thats a different plunger. Don't pull that. Main plunger articulates off the metering plate up the middle.

[dn010]

You can remove an injector, place it in a bottle and then jump the fuel pump. If it is spraying fuel when you jump the pump then the plunger is stuck. If it isn't spraying (it may drip), you can test the plunger by pushing on the air meter plate. It will begin to spray fuel if you press it down. Keep in mind, you will have only one injector in a bottle - unless you remove them all and point them into bottles or containers, they'll ALL be spraying fuel into their cylinders. Also, you should feel some resistance pressing the plate down with the fuel system charged up to pressure (engine not running), if you don't feel anything and the plate just pops down and back up easily when charged then it's more than likely stuck.


If your car has sat for a long time with ethanol fuel charged in its lines, then there is a chance, even with a free plunger, that the o-rings are shot in the fuel distributor. When I had K jet and after sitting for a length of time, my engine would spew white smoke and even drip raw fuel. I disassembled the FD to find some o-rings had turned into goo.

[DMC-81]

If you are flooding the motor with that much fuel you should check to see if the plunger in the fuel distributor is stuck.

I think there is an echo here.

Hmm.. Because it has been sitting for a long time and you smell fuel, I wonder if the plunger in the fuel distributor has gummed up a bit causing it to stick, or a similar fuel related problem. Maybe others can chime in on the correct way to test for this.

http://dmctalk.org/showthread.php?16...art-smell-fuel


Corey, I'm glad that you're on the right track. I know it's frustrating to chase an elusive problem. I think that the fuel systems in these cars can gum up quite quickly if not driven or run often. Speaking of fuel, I only use non-ethanol fuel in the D to prevent problems like the one Dan mentioned. Even in my 2006 daily driver, I had to replace the whole fuel tank because of a rubber gasket that was not rated for ethanol fuel.

[coreydmc]

Thank you for all your help! I was able to remove the fuel distributor. Those flat head pan screws were a pain. I hope using a hammer and impact driver didnt damage the fuel dist. The plunger was stuck but I pulled it right out with pliers. I will clean it up and re-install when I receive parts from PJ Grady. Rob Grady was awesome taking the time today on the phone to answer a few questions I had. I hope the plunger is my only problem for now. Only time will tell. Once I receive new o-rings etc.. I will report back!
Thank you everyone for your help it is greatly appreciated!

[David T]

If the plunger is stuck it is a sign that the fuel in the whole system has gone bad. You should empty the fuel tank, wipe it out, and inspect all of the internal parts. The injectors should be cleaned and tested. Just unsticking the plunger usually doesn't do it. Running very rich also contaminates the O2 sensor and it should be replaced.

[DMC VIN 6639]

If the engine starts and runs with no issue, what contributors can allow fuel into the oil. I just dropped my oil and I think there is fuel in it. It seems thin and smells like fuel. I think the previous owner had adjust the mixture screw. My thoughts are to check dwell, but I am curious what other failure modes to chase???

[Rich]

If the engine starts and runs with no issue, what contributors can allow fuel into the oil. I just dropped my oil and I think there is fuel in it. It seems thin and smells like fuel. I think the previous owner had adjust the mixture screw. My thoughts are to check dwell, but I am curious what other failure modes to chase???

You may not have a problem. Maybe there isn't excess fuel in the oil - a bit of it's allowable. Piston rings aren't perfect seals in any IC engine.

Recommending you get the old oil checked first to be sure, especially since the engine starts and runs fine. Analysis will tell you if there is excess fuel; also will report whether viscosity is OK. Costs about $30.

Links here to one engine oil analysis outfit plus an overview:

https://www.blackstone-labs.com/engine-types/gasoline/#

https://www.bobistheoilguy.com/engine-oil-analysis/

The most common excess-fuel-in-oil causes coincide with poor starting/running (rich fuel/air ratio and/or poor ignition) problems. Which the engine doesn't seem to have.

[David T]

The engine oil should NOT have a smell of fuel. If the motor is not running over-rich the oil would get hot enough to burn out any fuel that may have gotten into it. If it always smells of fuel you are running too rich and must figure out why. It could be a bad injector, an over-rich mixture adjustment, a stuck plunger, among many things. You say it is running well, do you know what you gas mileage is?