Motronic injectors

[e21-Mark]

I have a set of yellow injectors taken from a 730i (m30) and wanted to confirm that I could use them to replace my standard 2.5 motronic ones? I just figured their flow rates would be better suited to a 2.7 or would I be better off leaving well alone?

[--ALPINA--]

mark use the E36 2.8 or M3 injectors which are green tops, they are the same impediance as the 1.3 motronic 173/172, if you use injectors that has differenti impediance your blowing ECU`s and or the injectors wont work efficiently, like the solenoid in the injector wont open and close fast enough or just wont open at all and the car will run rough a.k.a. fuel starvation..... you can get mustang 14lb injectors that have same impediance but its an american thing to order unless some one has em here.. saying that alpina used standard 325 injectors and had no problems running their engines on.. you would only use bigger for more flow for turbo/supercharger/ heavy modded 2.7 e.t.c. and also changing the AFM to MAF you could use larger injectors which benefits more cos the airflow is non restricted and to keep the engine running smoother it need more fueling (little more) cos you cant adjust the MAF for its C0 content its all done by the sensor on the maf signalling the ecu on adjustments for fuel to air ratio... if you had the W.A.R chip like what i have you can use your laptop and adjust anything you want on the maf - like stand alone... thses newer injectors has 4 pintle holes which are designed for different blocks than the single pintle hole injector so sometimes over fueling the engine allthough it feels smooth to drive your actually wasting fuel the 325 e30 injectors are capable of runnin the 2.7 but as says changing them is another level to heavier mods on the 2.7... soon as you do change them the engine will need a C0 adjustment cos it will run rich...


Hope this helps.. if you need to know about pm/call/text me

J

[tommi_e21]

mustang injectors have different plugs aswell im afraid, i have a set of 8 of an AC cobra which im using for my turbo project

[quinn_656]

very informative alpina

[Jason_323i]

I would stick with the m30 ones and get them cleaned and flow checked, the m50/s50 are a 4 pin type and do not give the valve cooling that a single pin injector gives to the back of the m20 valve and both Ric Wood and Ant at A-tec recommend the single pin type for an m20 and as the m30 using the same spec of motronic they will be okay.

Jason

[--ALPINA--]

mark, miller uses mustang yellow injectors and anyone in the states that has E30 upgrades to mustangs, the flow rate is right and also the impediance is ecu tolerable. i end up fitting 2.8.m3 e36 injectors, they worked out better for me, its an indivdual thing regarding the type of engine your build is in all honesty, ive played around with loads of injecdtors, i had a box full i gave away after test trials and the names injectors came out better...


J

[tommi_e21]

valve cooling???

surely that just means that its over fueling and not atomising properly and a bit of a waste. good in turbo apps i spose