My car did not like new injector nozzles... - PeachParts Mercedes-Benz Forum

Rogviler · #1 04-21-2014, 08:06 PM

I have an '85 300TD, which has been running pretty well, but I've been noticing a bit of smoke and hiccuping on startup lately so I figured I might as well do new nozzles. It's one of the few things I haven't done any work to since I got it. I figured it could only help. Every thread I've read has said it was like magic for their car. I went with the Monarks since Bosio was too expensive for this car and I've read the warnings about the Indian Bosch ones. Seems like everyone likes the Monarks...

Well, now the car smokes constantly and has hard nailing with no power at all. I've already pulled them back apart and cleaned them again to no benefit. Other than not being calibrated (which I don't have the equipment or desire to do), is there anything else that might be the issue?

The only similar threads I've found are these:

Replaced Nailing Monarks with Original Bosch - welcome back!

Nailing after rebuilt injectors

But mine is like, I didn't even want to drive it around the block as soon as I pulled out of the driveway. It's not just the First-World problem of a slightly annoying noise. I don't want to ruin the engine if all I need to do is swap back to the old nozzles and save these for the future when maybe I'll want to put more money into it...

Anything easy I should check before I swap them back? At least the injectors will be nice and clean for all the effort. I was thinking pump timing, but I don't have the ability to do that this week and I need to know the car can be back on the road by Monday or so. Is there a "close enough" method? Haven't run across one but I thought I'd ask.

-Rog

greazzer · #2 04-21-2014, 08:23 PM

What PSI did you set them at?

Rogviler · #3 04-21-2014, 08:35 PM

Like I said, I didn't do any calibration. I know... But I had seen enough people that didn't need to (and the instructions from MS said as much) that I was hoping I'd be lucky as well. If that's the issue then it'll have to wait.

-Rog

vstech · #4 04-21-2014, 08:40 PM

This is why we don't promote ms on this site... Bad info, passed along as gospel, and charging for info from the free fsm...

vstech · #5 04-21-2014, 08:43 PM

Get some lapping compound, and lap the bodies smooth, this will bump the pop pressure a bit, and may bring the timing of spray where it needs to be.
Personally, I'd swap a used set in, and send the new to greazzer to balance.

greazzer · #6 04-21-2014, 08:51 PM

Whoever told you or suggested that pop testing AND balancing was not really necessary is nuts. I can tell you this. A certain company by the initials M S sells rebuilt injectors for around $450-ish. Every blue moon or sooner, I get those same exact injectors and I re-do them with my service. Every single time, guess what? Those injectors are not balanced or at the correct PSI, e.g., FSM says 50+/- PSI, but I tend to get 25+/-PSI give or take and 135 BAR is a nominal 1,950 to 2,000, just depends where the injectors shake out and where you pick to set them and your target. New nozzles are OK at 2,000.

Rogviler · #7 04-21-2014, 09:05 PM

I see... Between DG (which didn't mention calibration) and MS, which said it's "usually" not needed, that's what I followed.

Okay, so I will hang on to the new nozzles until I can send them out to someone for proper balancing and shimming and all that. I'll probably have to find an extra set of old injectors to send out as I can't have the car down for that long.

Thanks for the info.

-Rog

Diesel911 · #8 04-21-2014, 09:13 PM

Quote:

Originally Posted by greazzer

Whoever told you or suggested that pop testing AND balancing was not really necessary is nuts. I can tell you this. A certain company by the initials M S sells rebuilt injectors for around $450-ish. Every blue moon or sooner, I get those same exact injectors and I re-do them with my service. Every single time, guess what? Those injectors are not balanced or at the correct PSI, e.g., FSM says 50+/- PSI, but I tend to get 25+/-PSI give or take and 135 BAR is a nominal 1,950 to 2,000, just depends where the injectors shake out and where you pick to set them and your target. New nozzles are OK at 2,000.

X2

Diesel911 · #9 04-21-2014, 09:24 PM

Quote:

Originally Posted by Rogviler

I see... Between DG (which didn't mention calibration) and MS, which said it's "usually" not needed, that's what I followed.

Okay, so I will hang on to the new nozzles until I can send them out to someone for proper balancing and shimming and all that. I'll probably have to find an extra set of old injectors to send out as I can't have the car down for that long.

Thanks for the info.

-Rog

DGs is a great Businessman because He has found away to sell His parts at exorbinent prices and how to get Customers to buy His Injector Nozzles by getting the Customer to think they can get away with just swapping the Nozzles.
It was a long time ago but I used to work in a Fuel Injection shop and we would not have gone trough the trouble to of Lapping the Parts and setting the Opening/Pop Pressures if we did not have to do thet.

If our Shop had done the Injectors with the results you got from swapping just the Nozzles the Shop would have quickly gone out of Business.
I agree with most of what is in the below thread except that I think the lapping og the parts should be done with a Plate of Glass and Lapping Compound or of course a real Lapping Plate.
How to Rebuild Injectors
http://vincewaldon.com/index.php?option=com_content&task=view&id=20&Itemid=28

Als if during the cleaning of the New Injector Nozzles you mixed up the Pintels/the center Valve Needle in the Injector Nozzles you have essentially ruined them because each Pintle is fitted to an individual Nozzle.

After the Injectors are properly rebuilt there is still a need for the Fuel Injection Pump to be retimed and of course if it has not been done the Valves need to be adjusted.

I put your thread in My notes.
Nozzle swap Injectors not Pop Tested nailing and smoking.
http://www.peachparts.com/shopforum/diesel-discussion/353883-my-car-did-not-like-new-injector-nozzles.html

OM617YOTA · #10 04-21-2014, 09:33 PM

Greazzer did awesome work on mine.

Rogviler · #11 04-21-2014, 11:10 PM

I definitely followed all of the non-contradictory instructions I could find, including doing them one at a time so they don't get mixed up. So I'm confident that it isn't a mistake I made during assembly. I never go into this sort of thing without a lot of research. Looks like I just didn't find all the info on it.

It's like watching a tennis match on some of it though, and I felt caught in a dilemma. For instance, one site said to lap them or they'll leak, another said do not lap them as it's too easy to screw up and then they'll leak... I lapped them because I'm good with small parts and it didn't worry me.

One site said to take the nozzles apart and thoroughly clean off the oil they come soaked in (though didn't say why). Another said not to do anything to the nozzles and just install them, as it's too easy to introduce dirt or whatever. I tend to agree with the latter, but since I wasn't sure why the oil should be removed I went ahead and cleaned them. I can't imagine why they would put oil on them that would cause a problem with their function, however.

Anyway, I'll swap the old ones back in tomorrow and confirm that it's back to normal. Good thing I saved them and labeled which injector they go in...

-Rog

ah-kay · #12 04-21-2014, 11:26 PM

I have a pop tester but I have not used it to calibrate any injector nozzle replacement. I use it pretty much to test used injectors are within spec. However, I did replace nozzles on a 300SDL injectors without pop testing them afterwards. I marked the nozzles halves before I unscrewed them. I cleaned/lapped the inside, sprayed nozzle with WD40 and put them back together. Tightened the 2 halves back to or very close to the mark. I found the popping pressure was very close to the spec afterwards.

I do not know whether you marked the halves or not. If you didn't then you may be screwed. I would put new or used injectors in there for now. I think it is a hit and miss crap-shoot to put the old nozzles back in.

Good luck.

Rogviler · #13 04-22-2014, 12:47 AM

That's an interesting suggestion. I had not run across that particular tip, so I didn't even think of marking the housings to line them back up. I don't know what I'll do if the old injectors don't put it back to normal... I imagine then it would be a question of a different torque setting and that's a lot of trial and error.

-Rog

ROLLGUY · #14 04-22-2014, 01:13 AM

Quote:

Originally Posted by OM617YOTA

Greazzer did awesome work on mine.

X2+= :-)

Do yourself a favor, and get a good used set of injectors (only $5 or less each at most self service yards) to put in your car while you send the others to Greazzer. You will be happy you did......Rich

cooljjay · #15 04-22-2014, 02:56 AM

Send them to Greazzer.....does anything else need to be said!

Before Greazzer came about and I was new in the mb world...I bought a set of rebuilts from ebay....I am planning on pulling them and sending them to Greazzer to confirm they were done correctly...as I also have a stuck heat shield that needs to be removed.

As was said MS and DG are totally bogus sites...but many of us have made the mistake of believing what they say...including me and I admit it.....

This is why we have this great site and benzworld to help newbies not make our mistakes.