Do Injectors "Settle In"? - PeachParts Mercedes-Benz Forum

Duncwarw · #1 01-21-2008, 01:10 PM

I replaced my injectors a couple of weeks ago and the MPG dropped over what we experienced with the old ones. Smoking may be worse and 0 - 60 was still pretty dismal I thought (22 sec).

Last night we took a drive in the cold to get fueled up at a place we'd never bought from before and I thought I felt an improvement on the way home.

The best mileage we have gotten to date was 28. Not bad.
After the new injectors, it dropped to maybe 22.

The Boss just called and she reports 28MPG today and 16 second 0 - 60!

Maybe we should visit that station more often. I can't believe that with all the different places we've bought fuel, only one of them has "the good stuff". Hence the question: Do injectors take time to settle in?

Paul

rrgrassi · #2 01-21-2008, 01:26 PM

Were the injectors pop, pressure and spray tested?

Duncwarw · #3 01-21-2008, 01:33 PM

Not on my end.

I live in a rural area and I don't know of any place nearby that I could have them tested. A local shop told me there was ONE diesel mechanic in the area but he may have moved on.

I could go the the city if need be. Wouldn't the rebuilder normally test them?

rrgrassi · #4 01-21-2008, 01:50 PM

They should test them, but that does not mean they do. That are some shops that even send the results with each one.

#5 01-21-2008, 02:47 PM

Are you sure you got the right ones?

Duncwarw · #6 01-21-2008, 03:10 PM

Not as bad question.

Having the "odd" MB engine, I would have thought getting the wrong ones unlikely. How would I know? Part number on the invoice is NA36X.

Thanks

#7 01-21-2008, 03:27 PM

NA36X is the correct injector.

Next question, did you use new heat shields?
[IMG]http://www.***************/secure/PartImages/068130219.jpg[/IMG]

Duncwarw · #8 01-21-2008, 03:33 PM

Whew! thanks.

Yes, new shields. It will be interesting to see if the MPG changes again.
I have no idea what would cause a sudden improvement like that but of course I'm not complaining.

Even if it stays the same or improves I'd still like to deal with the smoking.
I feel guilty every time I start the thing.

Diesel911 · #9 01-21-2008, 09:34 PM

Quote:

Originally Posted by ForcedInduction

NA36X is the correct injector.

Next question, did you use new heat shields?
[IMG]http://www.***************/secure/PartImages/068130219.jpg[/IMG]

And, were they installed correctly?

Duncwarw · #10 01-21-2008, 09:40 PM

I looked at the orientation of the ones that were in there and looked at how they would mate with the injectors.

So, I believe I installed them correctly.

lupin..the..3rd · #11 01-21-2008, 11:15 PM

Quote:

Originally Posted by Duncwarw

I looked at the orientation of the ones that were in there and looked at how they would mate with the injectors.

So, I believe I installed them correctly.

Concave side must face up. Opposite of what you see in the photo above.

Bio300TDTdriver · #12 01-21-2008, 11:43 PM

Quote:

Originally Posted by Duncwarw

I replaced my injectors a couple of weeks ago and the MPG dropped over what we experienced with the old ones. Smoking may be worse and 0 - 60 was still pretty dismal I thought (22 sec).

Last night we took a drive in the cold to get fueled up at a place we'd never bought from before and I thought I felt an improvement on the way home.

The best mileage we have gotten to date was 28. Not bad.
After the new injectors, it dropped to maybe 22.

The Boss just called and she reports 28MPG today and 16 second 0 - 60!

Maybe we should visit that station more often. I can't believe that with all the different places we've bought fuel, only one of them has "the good stuff". Hence the question: Do injectors take time to settle in?

Paul

Your 0-60 time is slow. You should be closer to 11 seconds.

2.5Turbo · #13 01-21-2008, 11:49 PM

Quote:

Originally Posted by Bio300TDTdriver

Your 0-60 time is slow. You should be closer to 11 seconds.

Yeah...check your boost line to the ALDA and make sure it isn't plugged. Also be sure the turbo is good and is making at least a little boost.

But still, I'd think you would be getting better than 22 seconds. When my turbo wastegate was held open by the computer, I was getting 18-19 seconds 0-60 with one less cylinder than you.

Diesel911 · #14 01-21-2008, 11:55 PM

Quote:

Originally Posted by Duncwarw

I looked at the orientation of the ones that were in there and looked at how they would mate with the injectors.

So, I believe I installed them correctly.

If you drop them in the hole sometimes the heat shields will flip over. I slide them down a long skinney screwdriver. When they are all in I take a strong flashlight and look down each hole to double check they are positioned correctly.
Another thought; is it possible that some hose or plastic connector got pulled out or broken while you were working. It happened to me. I did not know I broke off the vacuum connector at the brake booster vacuum line until I tried to shutoff my car.
What color is the tail pipe smoke?

Duncwarw · #15 01-22-2008, 08:53 AM

That's how I did it. Not only were the old ones WAY over torqued, but I had to "persuade" the shields out.

Thanks for the Alda tip. That's where I'm going next. I've done some reading here and that seems to come up a lot.

The start-up smoke I think is blue at first and then white. There's also a miss. That's what makes me suspicious of stem seals (if used) and maybe dumping fuel. The smoke is really bad but it does clear up. Once on the road and warm the only time I notice smoke is on kick-down in the headlights behind me.