Injector pump need replacing? - PeachParts Mercedes-Benz Forum

mkrazy1 · #1 03-26-2011, 02:02 PM

I have an 87 300D with 135k. This week it started running horrible. When you first start it (in the 30's and 40's) it starts okay but immediately starts bogging down and smoking like it's running real rich. The exhaust smells like it is pooring diesel into it. After it warms up, it runs okay.

I have researched and looked at many threads and figured I would look at the alda. Well, mine does not have the setup I see in the postings. It does not have a banjo fitting on the manifold. It is plumbed to a solenoid that looks like an after-thought mounted on the driverside shock tower. Anyway, I hooked up a vacuum tester and the alda doesn't really hold vacuum very long but if I pump it up to 20 it'll leak down to 0 in about 10 seconds. I started the car and manually used the vacuum pump on the alda and it didn't make a difference.

I then took off the crossover pipe on the intake and it is pretty nasty with soot inside but I don't think it is sucking oil from the turbo. It is a bit wet, and if anything, it smells like diesel fuel.

I have been seeing diesel fuel dripping from the bottom of the engine after it is parked for a little while but was figuring I'd wait for warmer weather to investigate. Anyway, I looked at the injector pump and it looks like all the fuel I'm seeing is leaking from it.

What I am wondering is if the injector pump can really just start pumping extra fuel into the cylinders and if it sounds like it should be replaced. From some of the threads I read, it really isn't recommended to try, but I could replace the delivery seals.

How hard is it to pull the pump and replace?

Thanks for all your input!

Aquaticedge · #2 03-26-2011, 02:10 PM

I doubt it's the IP. Check all your filters, they can get clogged up. As for the intake. I bet you have a EGR on there. they tend to cause nastyness, I'd start with filters.

1stbenznc · #3 03-26-2011, 02:20 PM

Doesn't sound like a vacuum issue with the banjo/overboost lines being clogged up, as there is no pressure at idle. They should still be checked and cleaned however! (The line from the fitting on the drivers side of intake manifold ("banjo") to the overboost protector on the firewall/shock tower and back to the Alda. Shoot Brake cleaner through when lines are off)

As above, filters first. Then I would do a "Diesel Purge" procedure to try and clean up any trash or clogging in the IP or Injectors.

I believe the alda will give the initial off-the-line smoke; but if it's ruptured, it would do it when cold or warm.

bobodaclown · #4 03-26-2011, 03:54 PM

Is the top of the IP all wet? http://www.peachparts.com/Wikka/OM602InjPumpFuelLeak
Removing the Pump:
http://www.peachparts.com/Wikka/OM603InjectionPump

Keep us updated.

Diesel911 · #5 03-26-2011, 06:18 PM

x2 on the EGR problem.

mkrazy1 · #6 03-26-2011, 08:34 PM

Thanks for the ideas! The filters aren't that old and the prefilter is perfectly clear still. This setup does not have a banjo bolt. The line coming off the alda splits with both lines going to solenoids. One solenoid I believe is the overboost protector because the other line going to it goes to the intake, and the other solenoid has lines coming off going to the trans modulator? No banjo bolts!

The top of the pump isn't wet at all, but it looks all wet between it and the block and looks to be running down the back. Thank you for the links!

I will check the EGR and let you know!

mkrazy1 · #7 03-26-2011, 09:58 PM

I pulled the EGR off and it is closed tight. I can't force any air through it.

josha37 · #8 03-26-2011, 11:45 PM

It is hardly ever a egr valve that fails that way, more than likely it is what controls it, leave it un-hooked it is just choking your car anyways. like all that gunk in the intake? you can thank your egr valve

aaa · #9 03-27-2011, 07:41 AM

If you says the pump's leaking then the pump's leaking... find the leak, could just be a hose.

Diesel911 · #10 03-27-2011, 01:29 PM

Quote:

Originally Posted by aaa

If you says the pump's leaking then the pump's leaking... find the leak, could just be a hose.

"it starts okay but immediately starts bogging down and smoking like it's running real rich. The exhaust smells like it is pooring diesel into it. After it warms up, it runs okay."

I do not think his leaking IP is causing the above problem. He simply has the above problem and a leaking IP.

mkrazy1 · #11 03-27-2011, 02:39 PM

Sure enough, I disconnected the EGR and it runs much better. I hooked up the vacuum gauge to the line, and when you start it, it goes up to about 10 to 15. It does eventually drop down after a minute or so. As you accelerate it, it goes back up to 15 or 20 just off idle. No harm in leaving it plugged I guess? I started looking for the leak on the pump and I see the line coming from the filter to the first injector is wet, so I think it is leaking there, and running down the line going to the pump.

I took some pictures of the alda plumping to post, but I just reloaded the pc and can't get the pictures from the camera to the pc. I'll do that and post the pictures.

Thanks everyone. I'll be driving it later today so I'll post to let you know if it is back to how it was.

mkrazy1 · #12 03-27-2011, 03:10 PM

I attached some pictures. I tried to show how I have two solenoids for the ALDA. The other couple show the pump. You can kind of see how wet it is between the pump and block, but I do believe it is coming from just the the one injector line!

bobodaclown · #13 03-27-2011, 07:19 PM

Looking at the last picture, it looks like a 20 cents fix. O-ring replacement on the shut off valve. Really! Only a 20 cent O-ring and 10 minutes.