Injector Upgrade/Replacement
 

So I might get backlash from a lot of users but this is more of a proof of concept I suppose. Most owners I talk to with an m42 are familiar with switching the injectors in their e30's to a 4 pintle design found in ford vehicles (v6?) and volvos (http://theiconicbmw.com/about-me/tech-articles/chasing-efficiency/bosch-design-iii-fuel-injectors/). There is a lot of documentation out there with owners doing such replacements and having a lot of luck and praise the upgrade. BUT most e30s with m42 engines do not have vacuum lines attached to their injectors like our m42 318ti's do or m44 for that matter. I'vs read multiple users deleting the hoses and capping off the tree to the injectors and having no issues. Has anyone tried this? Since it is downstream from the MAF i dont believe a rich/lean fuel mixture scenarios is likely, and if anything this would reduce the possibility of a vacuum leak occurring under the intake hence improving reliability in a sense. So improved atomization (smoothness and economy) and reduction in vacuum issues sounds like a win win to me? Any thoughts? And yes, I know, leave it stock, BMW engineers are genius, etc. etc. but wondering what you guys think.

I believe the stock injectors are 4 pintle but they are in the old injector body style. There are people who have deleted the vacuum lines and seen no difference in fuel economy which leads me to believe it may have just been incorporated to help reduce emissions or something.

The main issue with the stock injectors is that they are shorter than the standard size, VAC makes an adapter to use regular size injectors in the M42/44.

https://store.vacmotorsports.com/vac...ors-p2454.aspx

Thanks for the quick reply, well that's both good and not so good news. Good, that it'll work and that the injectors don't need vacuum lines; not so good, because I'll need to buy more stuff :redface:. I suppose it's worth it :smile:.

Yes, I just found out that Bosch has gone back and superseded their injector replacements for the M52/S52 pink tops that are stock on the car. If you go to Bosch's aftermarket part search they have an EV6 style injector as the direct-fit replacement.

To me this is the best way to go if you want EV6 style, find ones that are spec'd correctly by the manufacturer. On bimmerforums there is a guy selling rebuilt injectors that I fell for back when I did my swap. He literally sent me two different style injectors, 2 of one 4 of the other, and because they were all pink he sold them as EV6 replacements for the stock pink tops, I looked up the part numbers and found the injectors he sold me had wildly different flow rates than the stock injectors. Luckily, I got my money back but that could have been bad if I'd tried to run them.

If you want to run stock flow rate, just remember that the stock fuel pressure regulator is 3.0BAR vs the 3.5BAR that the 325/328/M3 uses. So when people reference 19# injectors for the M42/44 that isn't necessarily the flow you'll get from the 19# injectors for the 325/95 M3.

I didn't know this. I thought that all the E36 FPR's were the same. That's good info, for swap people especially.


I guess I don't understand the value in the rest of it, capping the lines. Seems as easy to just keep them in decent shape.

Yeah, the FPR is an easy thing to miss when doing a swap especially with it under the car on later tis.

Some people want to simplify and reduce the potential area for vacuum leaks. The reports I've seen of people capping everything off say there's no performance or fuel economy impact.

The adapters are worth the money long term with the better performance from the newer injector style with better atomization. Coupled with my tune this turns the m44 into a fun little beast .

I received and picked up the injector adapters in the mail today. These are super light but look very well made. I slid my injectors on and well, yeah, I guess they're ready to install, right? Don't I need a rubber O-ring for the injector+injector adapter to seat well/tightly into the manifold?

Yes, you need o-rings for the groove on the adapter, i'd imagine it's the same o-ring as what's on the stock ti injectors.

Alrighty, got them in, along with the COP kit, fuel filter and fuel pump. Will do a more comprehensive mess under intake job later. Starting was a bit nerve wracking as it was hard to start and lumpy but after a while it smoothed out and is running nicely. I'm guessing the fuel pressure took a while to build up and normalize. Thanks for the help! :biggrin:

Which injectors did you go with?

I went with the 0280155746 EV6C style injectors found in Volvos. Attached you should see the specs. Pretty much the same thing except the resistance is slightly different, probably negligible. Flow rate is the same, but I believe another difference is that these are a disc type injector vs the latter (pintle?):confused:. Maybe. I'm not sure.. but most importantly they work, and the engine runs smoothly. As far as economy, still early too tell.

Nice, thanks for posting the spec sheets, will be good reference for others in the future. It's also important for the injectors to have the groove at the top for the retaining clip, which yours do.

No problem. I've seen so much injector model numbers being thrown around without much proof, or specs written down. At least this way individuals will know a direct replacement without second guessing. Now, I know the yellow/orange Volvo injectors work but digging around deeper and just looking through the Bosch catalogue I've stumbled across the 0 280 156 161. These are 12 hole EV6E type injector used in Jeeps and some Ford models. They use a USCAR type plug vs a jetronic, but adapters are easily attainable. I'm curious if these would work... they have a lower resistance (12.00 ohm) and higher flow rate (172.00g at 3 bar; our system would limit it anyways right?). They might be worth looking into, maybe when building a stroker...:confused: I'm still fresh to the game so I'm not too sure; just food for thought. Attached show injector spec, body type and bosch nomenclature/connector types.