Injector Pump Failure, '96 E300 - PeachParts Mercedes-Benz Forum

Jwoos · #1 06-04-2006, 10:52 AM

I posted an earlier thread on the poor acceleration problem on my '96 E300D. Now I am being told the injector pump needs to be replaced.

What are the normal symptoms of injector pump failure?

The car is harder to start than it was before, I feel like I have to drag it to life instead of starting instantly. Its acceleration is very poor until it gets to about 1,000 rpm, then it accelerates well. It will run at highway speeds, 70-75 mph just fine. There is a little roughness it did not have before at idle speeds.

I ran a few tanks of Waste Veg. Oil through the car. I used a 10 micron heated filter (Fattywagons) but I stopped running WVO because I was having trouble with water. When my problem started I had run several tanks of pure diesel through the car so there was no WVO in it when the failure happened but I wonder if the WVO and/or the water may have damaged the IP.

The problem started all at once, I was driving down the highway at 70 mph when I felt a change in the way the engine was running but it kept on going. When I came to a stop, I found that it was very hard to accelerate.

Does this sound like the IP is a reasonable cause for the problem?

TheDon · #2 06-04-2006, 11:03 AM

did you change the fuel filters at least?

banshee350 · #3 06-04-2006, 12:23 PM

did you have a heated seperate system for your veggi or were you just putting it in your diesel tank? If the latter you may have also clogged up your in tank screen.

Jwoos · #4 06-04-2006, 02:11 PM

I have changed both the original fuel filter and the new one I put in. I also found out there is a secondary fuel filter alongside the original filter in the engine compartment, that is new also. I removed the tank screen after this started. It was pretty nasty but it is gone now. In any case, the weird thing is that the car runs great at high speed, won't run well at low speed. That is backwards from what you would expect if it were a fuel filter problem.
I am using a heated fuel filter and injector heaters for the WVO.

Palangi · #5 06-04-2006, 07:22 PM

That other thread ran for 3 weeks, and you never mentioned alternative fuel experiments??

barry123400 · #6 06-04-2006, 09:57 PM

It may not be a waste to pull the injectors and have them tested. Badley messed up they might run much better at higher revs. Should be pretty cheap just to get them tested. The pump is so expensive it would be a shame to go there first although it is a possibility.

Jwoos · #7 06-04-2006, 11:16 PM

How do you test the injectors? Will a mechanic know what that means? Sometimes there are differences between the terminology used on the forum and the words the mechanics I work with know.
I had stopped using the alternative fuel several weeks and many fillups prior to the failure so I was not making a connection in my mind between one thing and another. Everybody on the forum talked about EGR's and crossover pipes, things that would not have anything to do with what kind of fuel I had used in the past, I thought.

sailor15015 · #8 06-05-2006, 12:16 AM

I know my wvo filter on my two-tank system needs to be changed when It starts bogging down on take off, higher revs are fine. Not sure about your injectors but for the OM617, they can be tested with devices similar to the ones in this thread. It allows you to see the spray pattern, showing you what shape the nozzles are in and it also allows you to see at what pressure they "pop". I'm not sure if the injectors for your engine work on the same principles, i.e. they pop when the pump reaches a certain pressure or they open when a computer tells them so but a competent diesel mechanic should be able to check them for opening pressure and spray pattern.

Jwoos · #9 06-06-2006, 12:37 AM

My mechanic called today, said he found something called a fuel line heater prior to the injector pump that appears to be blocked. He ordered a new one, it cost $110. Does anybody know what that is? He wasn't sure of its function. This is a stock part, no relationship to the WVO conversion.

TMAllison · #10 06-06-2006, 01:06 PM

On my 99 E300, that line comes off a thermosat type heater mounted toward the front of the head which then connects to the filter housing.

If WVO has clogged everything up maybe you need to run a tank of B100 through it to dissolve any remaining goo?

husk · #11 06-06-2006, 01:26 PM

Who is your mechanic? I am in Orange County as well and I am a little curious.

DieselAddict · #12 06-06-2006, 03:37 PM

I think the WVO may have coated your fuel system with wax. This does happen occasionally when mixing diesel fuel with WVO. You should have told us about your WVO use in the previous thread. I'd try the StarTron fuel additive which should be able to dissolve this kind of gunk if it's present. Bosch diesel injection pumps are not known for frequent failures so I'd replace the pump only as a last resort.

Jwoos · #13 06-06-2006, 04:22 PM

I took the car to Exclusive Motors in Anaheim, Ron at that shop is working on it. I found him from this forum and am really impressed by him. His is the third shop I took it to, including the Mercedes dealership in Buena Park and we are all suffering from frustration at how difficult this has been to resolve.

Where would I get the Startron additive? I looked at the Buy Parts tab at the top of the page and type in Startron in the search bar but did not get any results.

winmutt · #14 06-06-2006, 04:52 PM

Dumb question, getting air in the fuel line? My car had this problem, ran great on highway, like crap at idle.

DieselAddict · #15 06-06-2006, 05:16 PM

Quote:

Originally Posted by Jwoos

Where would I get the Startron additive? I looked at the Buy Parts tab at the top of the page and type in Startron in the search bar but did not get any results.

Go here and see if there's a store near you. http://www.westmarine.com/ You may be able to buy it online as well.