which chip for E36 injectors?

[Daeldalus]

I have e36 injectors in my 90 325i runs better than my old leaky 14# stockers

what i want to know exactly is what chip i should get with them. i know that i am going to get a MarkD chip but on his site has a chip for 17#or19# injectors and i know that the same option used to be only for 19# injectors. so it seems to me that they just said "oh well they close enough so we will just label it for 17# too" and so by that logic it seems that on 17# injectors that chip may run a bit too lean as it was designed for 19#'s. so would it be better to just go with the chip designed for the stock 14.5# injectors? i mean the e36 ones at the lower 3.0 bar fuel pressure of the m20 make them actually only 15.5# injectors and 15.5 is much closer to the stock injectors than the 19#'s the other chip was made for and instead of being a bit lean it would be a bit rich which is safer for the engine in general.

but all this is just my thoughts on the subject. i really do not have any experience with the products. so has anyone run 17# injectors with a chip made for stock injectors? if so how was it? also has anyone here run E36 injectors with the MarkD 17#/19# chip? and how did it run? anyone got dyno maps of the A/F ratio with these setups?

am i just overthinking this? would it even make that much of a difference?

[jlevie]

If the O2 sensor is good and there are no other engine management issues, you don't need a chip for 17lb injectors. The DME has enough available fuel trim to accommodate those injectors and will learn what fuel delivery is required to get back to stoic operation. In a like manner, a chip for stock injectors should work. A chip for 19lb injectors sounds like a bad idea.

Also note that there will be no performance advantage from larger injectors without some serious work to the engine internals and tuning to match.

[Daeldalus]

yeah I know there are not any performance gains to be had with e36 injectors but my stock ones were leaking fuel everywhere and were really in bad shape and i found a cleaned and flow matched set of e36 ones for cheaper than stock ones and the e36 injectors are a 4 pintel design so i went with those.

and i don't KNOW that the chip is designed for 19# only but i kind of suspect it. which is why i'd like to hear from people who have tried it. with the sheer number of people who switch to the 17# injectors i figure someone out there has to have gone through all this.

[MR 325]

For an off the shelf "generic" performance chip I prefer the Turner aka JC chip.

I've used it with 17lb injectors in many vehicles and am always happy.

[CabbE30]

I have 17# injectors with a 91oct Mark D chip. It runs good. I get better fuel economy than I did with the stock injectors ecu.

[603Racing]

I have 17# injectors with a 91oct Mark D chip. It runs good. I get better fuel economy than I did with the stock injectors ecu.

Same. I switched to 17# w/ MarkD 93 octane chip. Averaged just over 18mpg before the switch and just under 20mpg after. Not a huge increase, but an increase in addition to slightly better performance.