Good morning everyone! I pulled my fuel rail, removed my blue injectors and installed my purchased, cleaned, checked, flowed and rebuilt black injectors. Does anyone know if one color flows more than the other? My 2006 blues are 0280156304 or A1130780123 and the 2005 blacks are 0280156072 or A1120780349. As for me I think the blues are faster but we all know how fast blacks are too. Seriously though, I found a post on MB World saying the blues flow more but I can't find proof. If I find out the blues flow more than the blacks I'll send mine out to be serviced and put the blacks up for sale. Anyone know or have a more advanced search degree than mine?

Les

I just found the answer in a thread I posted in years ago. It looks like the 304's are going out for service.

BTW, when I went to relieve the pressure in the fuel rail nothing came out! I unscrewed the supply line and there was no pressure present. What do you think about that?

 

BTW, when I went to relieve the pressure in the fuel rail nothing came out! I unscrewed the supply line and there was no pressure present. What do you think about that?[/QUOTE]

Hi Les, I had the same concern with mine. I did the leak down test that we have in the service manual to determine whether it was the check valve in the regulator; or the check valve in the fuel pump. Mine was apparently the fuel pump check valve, although I still haven't changed out the pump. Service manual says that quick loss of pressure indicates the check valve in the press. reg., and a slow loss indicates check valve in the fuel pump(this is of course after determining that it's not leaking through an injector).
It doesn't seem to be a problem for us, as it starts up OK, but perhaps it would start instantly instead of a second or two if I changed out the fuel pump. Didn't you just get a new 55 pump? Mine leaks down to near zero pressure, but holds just enough(maybe 1/2psi) to keep fuel in the lines. How long should a healthy check valve hold fuel pressure? A week, a month; I don't know.

 

Hi Les, I had the same concern with mine. I did the leak down test that we have in the service manual to determine whether it was the check valve in the regulator; or the check valve in the fuel pump. Mine was apparently the fuel pump check valve, although I still haven't changed out the pump. Service manual says that quick loss of pressure indicates the check valve in the press. reg., and a slow loss indicates check valve in the fuel pump(this is of course after determining that it's not leaking through an injector).
It doesn't seem to be a problem for us, as it starts up OK, but perhaps it would start instantly instead of a second or two if I changed out the fuel pump. Didn't you just get a new 55 pump? Mine leaks down to near zero pressure, but holds just enough(maybe 1/2psi) to keep fuel in the lines. How long should a healthy check valve hold fuel pressure? A week, a month; I don't know.[/QUOTE]
From the Manual
7. Pressure should not fall below 2.5 bar (36 psi) after 30 minutes.
8. If pressure falls below 2.5 bar (36 psi) within 30 minutes, it must be determined if a fuel injector, the check valve within the fuel pump, or a fuel tube/line is leaking.

 

I've never had a problem starting but I've had AFR's fluctuating more than I liked. Recently it's gotten worse. I'd suspected/assumed/hoped it was because of the O2 sensor location in the headers but now I'm thinking, well you can imagine.

Yes, I have a Pierburg pump on the desk. I'm waiting on the new fuel filter/regulator and IAT sensor which has shipped. Monday is Veterans day but I'm hoping to have them on Tuesday. I'm actually having a good time working on my car. I've never messed with fuel rails and injectors etc. It's not difficult at all. I hate having to remove the manifolds to get to the Y pipe, meth nozzle, injectors etc. but only because of the gasket sealing crap shoot. I'm sending out my original injectors to be serviced and if they flow more than the blacks I'll put them back and sell the blacks.

Les

 

Mine leaks down to near zero pressure, but holds just enough(maybe 1/2psi) to keep fuel in the lines. How long should a healthy check valve hold fuel pressure? A week, a month; I don't know.[/QUOTE]
From the Manual
7. Pressure should not fall below 2.5 bar (36 psi) after 30 minutes.
8. If pressure falls below 2.5 bar (36 psi) within 30 minutes, it must be determined if a fuel injector, the check valve within the fuel pump, or a fuel tube/line is leaking.[/QUOTE]

Dave, I think you missed my point. I did the tests from the manual, so I know about items #7 & 8. The point is that it shouldn't fall below 36 after 30 minutes, but it does, and still operates fine. Manual doesn't say whether it can fall to zero after 1 hr? 1 day? Is it supposed to hold pressure indefinitely? I doubt it.

 

I do not think I missed your point, obviously the pressure will fall to atmospheric pressure over time, how long is a guess. All dynamic seals and valves leak, the closer the pressure gets to the ambient pressure the less they leak. Nothing seals forever, that's why Depends was invented.

 

After spending some quality time on Google it seems perfectly normal for the pressure to bleed down to 0 over night. I didn't think so but it seems so.

Les

 

Ha. Thanks for clarifying that Dave. Just saying, that if you don't have pressure at the rail when your getting ready to open it up, that it must not be a big deal.

 

If you don't mind, please post up the flow data from both sets as the A1120780349 is superseded by A1130780123 and I know of a few cars running around with 5 originals and one new one and curious how much of a difference they may have with one hole.

 

Sure thing. I had the spare blacks serviced by Marren and I'll send my blues to them on Tuesday. They take about 2 weeks plus the trip back and forth. I've got a race on the 9th and a 1/4 mile rental on the 15th which I'll run with the blacks unless I have good reason not to.

Les

 

I had the 304s serviced and the flow data is on here somewhere. The nice thing about them is they don't clackity clack like the stockers.

 

I found your info. https://www.crossfireforum.org/forum...tml#post607895
Mine were tested at 3 bar if I'm not mistaken. Here's the numbers from my blacks, post # 20. https://www.crossfireforum.org/forum...arts-sale.html

Les

 

I received my blue injectors from Marren. The box was opened 5 minutes ago and I'm still comparing them. 072's are blacks and 304's are blues. Blacks are 14.8 ohms and blues are 15 ohms. Static flow / blacks 410 cc at 43.5 psi and blues 460 cc at 43 psi. Check out the flow volume and don't ask why the blacks were flowed at 43.5 and the blues at 43 psi. I don't have an answer. Comments?

Les

 

It's good to know the flow numbers are as close as they are between the two since they are using the new with the old. The curious thing is the 410cc vs 460cc given the pulsed flow numbers and that would make sense for the upgraded part number to flow more static. Would be nice if they had flow data for 80, 85, 90 and 95 IDC in addition to static.

Thanks for sharing Les!

 

The volume test at 43 psi seems to favor the blacks. Static flow, which no one wants to use, the blues. I'm left wondering if one is better than the other.
I figured the blues were dirty because my car sat 2 years before being sold, to me.

Les

 

I know testing at 43psi is a standard but our fuel presure is set around 60psi so those aren't true numbers as they relate to our fuel system. Thus, those injectors are flowing more than what is stated in the testing phase. I wish they had a conversion table for flow based on different fuel presures.

 

I actually see it the other way around. The static pressure would indicate that they changed something so the higher the IDC, the less the injector choked. Neither of them should ever see higher than 85% duty cycle but when you start approaching it, I'm guessing the blue ones will perform better. I'd also guess with that in mind, that they flow better at higher pressures as well. One thing I do know is Mercedes didn't have this new injector spec'd for the heck of it and it probably has nothing to do with how it performed with the M112k but rather the M113k. which incidentally, these came out about the same time the SL55 got the 80mm TB upgrade.

 

Good observations Rudy. The blues are going back in. Anyone need a set of freshly serviced blacks?

Les

 

same.....same...

Been running a mixed batch for years and years and years...

Perhaps if you super boost the fuel PSI you might see some marginal change......

MB lists them as a direct replacement....