replacing pintle cap w/ 4-nozzle on stock injectors

**jdusty4** · 05-11-2015, 08:36 AM

Emailed the seller, and he would not confirm that these are stock, and said he would take down the part number to avoid confusion, and recommended I get the green-tops. I still wonder if it would be possible to replace the pintle cap with 4-nozzle, but that's not what these are.

**packratbimmer** · 05-12-2015, 12:00 PM

The auction does not give a flow rate so I would be cautious.

My opinion is that injector upgrades should be accompanied by a proper tune/chip.

The M20 1.3 is adaptive, but I question the ability to deal with severe cold warm-ups - I see that you live in Chicago. I live in ME so I have some experience too!

I tried a similar set of injectors and they ran very rich. I have a black set of plugs to prove it!

**TurboJake** · 05-12-2015, 07:42 PM

Originally posted by jdusty4

Looking into getting rebuilt injectors, and I read a bunch of discussions about whether or not to switch to m50 injectors. I decided I didn't want to mess w/ different flow rates etc on my stock setup, and was just going to go with rebuilt stock injectors - the part number according to the Bentley is 0280150715. But then I came across these on eBay:

http://www.ebay.com/itm/3-Year-Warra...6b215d&vxp=mtr

They claim to be the stock injectors with, as I understand it, the single-pintle cap replaced with 4-nozzle caps. Has anybody done this? It would seem to address the atomization question without any worry about different flow rates, etc.

Those are NOT stock injectors replaced with 4 pintle. They are an entirely different injector.

More specifically, they are bosch 0280155771 injectors. Flowing 196cc @ 270kPa (18.7lbs @ 2.7 BAR). They come from a 1998-2000 Mercury Mystique, and I would HIGHLY recommend getting them from a different seller. One that doesn't attach BMW to them, such as this guy.
http://www.ebay.com/itm/Set-of-6-Flo...7c0920&vxp=mtr

I run them, they're great, HOWEVER I cannot speak for stock applications. I mated them up with a 2.5 BAR FPR from a 325e, a MAF conversion and a WAR chip, tuned them out and they're right as rain. (Didn't do much for tuning, it ran great with the stock 14lb map) INSTANT throttle response and no richy richness.

**AndrewBird** · 05-12-2015, 08:11 PM

M50 injectors are the same flow as M20, only 4 pintle design. Check out user MEPEH. He rebuilds injectors and also sells them on his website.

http://www.r3vlimited.com/board/showthread.php?t=266477&highlight=clean+injectors

I had him rebuild a set of junkyard injectors and I am very happy with them.

**TurboJake** · 05-12-2015, 08:50 PM

Originally posted by AndrewBird

M50 injectors are the same flow as M20, only 4 pintle design. Check out user MEPEH. He rebuilds injectors and also sells them on his website.

http://www.r3vlimited.com/board/showthread.php?t=266477&highlight=clean+injectors

No they are not. They are 17.5 lb injectors @ 3.5 BAR, 16.2 @ 3 BAR, and are VERY close to stock running an E FPR at 14.8 lbs @ 2.5 BAR.. Stock are 14.1 lbs @ 3 BAR

If you really want to get Gen III OP, and not have to deal with anything else, go with bosch 0280155847 or 0280155969. Otherwise, go simple and do m50 4 pintles at with an E FPR, which I would recommend if you're already confused.

**packratbimmer** · 05-14-2015, 04:20 PM

Just installed my MEPEH M50 injectors with a 2.5 bar FPR. Started up and idled great so I'm optimistic. Can't wait to take it out and let the ECU adapt.

**cabriodster87** · 05-14-2015, 10:50 PM

I think starting on very cold days with these injectors will be difficult, ask me how i know. lol

**packratbimmer** · 05-15-2015, 03:19 AM

Interesting - explain???

**cabriodster87** · 05-15-2015, 05:04 AM

Seems like to much fuel on cold start. I had to pull fuel pump fuse for any hope of a successful start.
It is funny that i can reach that fuse and turn the key simultaneously.

**packratbimmer** · 05-15-2015, 08:23 AM

Hmmm? Not sure if you saw that I installed a 2.5 bar fuel pressure regulator as a short term measure (plan to get a SSSquid chip after I get my transmission seal replaced and back to driving the E30). As TurboJake states - The M50 @ 2.5 bar = 14.8 lbs. - very close to original flow rate. I also put a new coolant temperature sensor in while I had the rail out.

These a freshly rebuilt injectors - maybe yours were leaking down over night. I have not heard this complaint before, but I will certainly be watching.

So far so good - perfect start after a night in the forties. The car had been stumbling pretty bad on start-up, kicking out obnoxious fumes and refusing to move for a few minutes. Even without any adaptation time, the car started, idled and moved great this morning... without choking the neighbors - LOL.

Now I'm onto the fun rear seal job on the tranny. Should be back in business for the summer!

**cabriodster87** · 05-17-2015, 09:14 PM

i was responding to jdusty4 about these, sorry about any confusion.

**packratbimmer** · 05-18-2015, 03:53 AM

No worries. I tried a 19 lb version of those from eBay and my mixture was super rich too. Need to consult with a tuner who tunes to the specific type of injector.

Gets one thinking...If the modern injector atomizes the fuel better, is less fuel needed? injector rigs are based on fuel collecting in a jar after atomization has occurred.

**jdusty4** · 05-20-2015, 09:59 AM

TurboJake, thanks for the info. I have been wondering if there was a way to get the pressure closer to stock with the m50 injectors. Are there any other issues associated with running the ETA FPR?

Also - I used the values found here: http://www.unofficialbmw.com/phpBB/v...452277310c401b

M50 injector is 0280150415 190.2 cc/min at 50.75psi (3.5 bar),

at 2.5 bar (36.25 psi) that would appear to give 15.2 lbs/hr, not 14.8? (I used this calculatorhttp://www.rceng.com/technical.aspx#Find_Fuel_Flow_After_Pressure_Chang e)

Originally posted by TurboJake

No they are not. They are 17.5 lb injectors @ 3.5 BAR, 16.2 @ 3 BAR, and are VERY close to stock running an E FPR at 14.8 lbs @ 2.5 BAR.. Stock are 14.1 lbs @ 3 BAR

If you really want to get Gen III OP, and not have to deal with anything else, go with bosch 0280155847 or 0280155969. Otherwise, go simple and do m50 4 pintles at with an E FPR, which I would recommend if you're already confused.

**jdusty4** · 05-20-2015, 11:08 AM

ok, have found pretty conflicting info. the flow rate for m50 injector is listed differently elsewhere: 15.87 lb/hr (160 cc/min) at 3 bar. At that value, it would give 16.44 lb/hr (172.8 cc/min) at 3.5 bar, and 13.9 lb/hr (146 cc/min) at 2.5 bar.

These sources also list the m20 injectors (0280150715) as 155 cc/min at 3 bar (15.38 lb/hr).

This would make it sound like 2.5 bar would be too low, and that sticking with the 3 bar regulator would get you a flow rate (160 or 15.87) closer to stock (155 or 15.38) than a 2.5 regulator (146 or 13.9)

These are the sources that give these values for the m50 (0280150415) and m20 (0280150715) injectors. One of them claims to take directly from a Bosch-issued data sheet

Club G40 - The Polo G40 Owners Club UK

http://www.polog40.co.uk/article_injector_table.php

http://www.mepeh.com/6-rebuild-bmw-m50-bosch-fuel-injector-0280150415-13641730060.html

404 Not Found

http://accurateis.com/store/23641354-Injectors-calc-flow-data.pdf

Anyone know how to clear this up