Firstfives.org

Bmw.wp wrote:

DEMIURGE wrote:Firstly, I want to say that in my opinion, Mike and Chris are right - the old M30 injectors are identical (e12 era). Then in e28 era - they are the same also, but with another new geometry (same 19 lbs/hour) and in e34 era with only B30 and B35 engines - the injectors are with different part number and color, but the flow rate is similar (I'm not 100% sure).
So Blaise is right also...

Let us examine these two possibilities:
1. Injectors are with the same flow rate. Nothing new happens - the same amount of fuel, the same power.
2. Injectors with higher flow rate.
a. If your engine has no lambda (oxygen) sensor - the only thing will happen is overriched mixture, a very slight power increase under heavy loads and more fuel consumption. And I'm not speaking about the smog inspection case.
b. Your engine has lambda sensor - the the ECU will correct the overriched mixture to normal by shortening the injectors "open" time.
The result will be - the same output power.
Of course you can make some tests with tightening the spring of the AFM, change the ECU chip with new remapping (only for Motronic) and some other not advisable things... or change the ECU to MS2 (Peter Florance knows about it more then us put together)

So, in first place - you have to check - have you a lambda sensor and after that, if you have one - is it in good working order. If your lambda is faulty - the ECU already put the engine in overriched mixture position.

My personal advice - use the stock injectors for this engine with the stock ECU. They have a very serious reserve in the fuel flow rate. Everything depends on the ECU adequate commands. The only use to switch to aftermarket or other injectors is, when they use some new revolutionary way to spray and atomize the fuel.

DEMIURGE

Thanks for your input.

When i bought the 535iM i was under the impression that the engine is still an standard 3.5l. when my friend check it out he said "nope" this is a 2.8l engine.

So if the previous owner change the 3.5L to 2.8 but leave the Ecu of the 3.5l still in the car, then what happens.?

Just Curious.

Thanks for all the input.

i still going to keep my car as standard as possible. No Modifications