Can you have too much injector?

[BONE_STOCK]

I just picked up a 93 coupe with a 302, holly intake and heads, and a crane cam.
It's got 42lb injector's in it with a Pro-M MAF.

The guy was getting ready to put a D-1 in it but never got around to it.

The car hasn't been put together enough to run so I don't know if it'll run fine.

Can 42lb injector's be to much for a maybe 280rwhp engine?

 

[Bullitt347]

The answer is NO!. That is not to big of an injector. If the electronics are correct as in the right MAF and/or correct ECU tune/program, then the engine will run just fine. Think of it this way, my engine also has 42 lb/hr injectors, sure its supercharged, but 95% of the time the engine is not in boost, so it does not need the big injectors, or big fuel system, but it runs just fine at an idle, cruising and just plain driving around. During all of that time the engine could run just as well with the stock 19 lb/hr injectors. But when the engine goes into boost, only then does it NEED the big injectors. So your engine will be just fine with the 42's, it is just that the engine will never need the capacity or full flow from them is all. The ECU/MAF combo will just trim the pulse width to provide the proper amount of fuel.

 

[Grn92LX]

What he said ^ ^

 

[BONE_STOCK]

ha! make's total sense! Thank you!

 

[MY 85 GT]

Ok so if i was to buy a set of 42# injectors and a matching MAF sensor...would i be able to bolt them on and run the car fine...Have no starting problems...idle problems...Divabilty problems...Then down the road if i bolted up a Voretch V1- S-trim would this combo work...? 8-10 psi ???.....right now the car is basiclly stock..has Off road H-pipe and a cat back...soon shorty headers and a cold air intake thats it....but i have plans of going to a vortech....Thanks

 

[cardudeusa]

Wow, I never knew that, good to know!

 

[2002BLGT]

Ok so if i was to buy a set of 42# injectors and a matching MAF sensor...would i be able to bolt them on and run the car fine...Have no starting problems...idle problems...Divabilty problems...Then down the road if i bolted up a Voretch V1- S-trim would this combo work...? 8-10 psi ???.....right now the car is basiclly stock..has Off road H-pipe and a cat back...soon shorty headers and a cold air intake thats it....but i have plans of going to a vortech....Thanks

not necessarily , sometimes the calibrated MAFs are too lean , or still too rich under idle and midrange conditions , but nothing that cant be fixed with a good tune via , chip , tweecer or PMS and some time with a wideband ........but the calibrated MAFs can do other things like throw your load off that the ECM sees as well ......I wouldnt recommend a calibrated MAF over a 30lbs injector and matching MAF , anything bigger will probably end up needing a tune ....

 

[MY 85 GT]

not necessarily , sometimes the calibrated MAFs are too lean , or still too rich under idle and midrange conditions , but nothing that cant be fixed with a good tune via , chip , tweecer or PMS and some time with a wideband ........but the calibrated MAFs can do other things like throw your load off that the ECM sees as well ......I wouldnt recommend a calibrated MAF over a 30lbs injector and matching MAF , anything bigger will probably end up needing a tune ....

Ok so if i was to go 30# injectors and a MAF calibrated for them bolt them up do i still need the FMU? or can i ditch it then...Also im going to be installing a good wide band Air fuel gauge..to keep an eye on..so i dont run to lean or to rich..Also im installing a 255 lph pump...what else should i do?

 

[PAzYearazzUP]

I would think the ECU has no clue what size the injector is. It just sends in the telemetry and then the nano or millisecond opens the injector time and that is the fuel. So, you install a bucket injector you will have more fuel being the bigger plunger?
You use a cup size injector, you lean out. So, the bigger the number, the larger the jet. Besides, you need at least 43-44PSI behind the injector just to keep the pressure behind the injector for the thousands of spins it takes to repump or pressure up the injector in a bout a half second it will need pressure is not 5 to 10lbs of fuel pump pressure if that's what you mean.