Advanced auto parts had a different brand of 42# fuel injector to replace the one I broke from the other 7. Is it typically ok to do this?

 

Just make sure that the injector has the same offset values as the other injectors and you should be ok.

 

will it not run if it doesn't, or will it just run poorly?

 

It'll run but it may not be firing the same as the other injectors. For example, I threw Ford 39lb injectors in my car, but I ran the stock injector values for awhile. Car read lean all the time and would occasionally shut down. I figured out the proper injector offsets and burned a new chip and I have fuel correction functioning again. Car ran much better.

So in your case, if your new injector doesn't have the same offset values as the other injectors, then you may have one cylinder that is either richer or leaner depending on what the offset difference is.

 

gotcha, thanks for the help! this could be solved by a tune though?

 

Tune, no. Not unless you intend on replacing all eight injectors with the same brand that have the same offset values. The injector offset table in the PROM has no provisions for single injector calibration.

 

oh ok thanks. so how can i find out about the offset values? if i find the part number, will they say on a mfr site or something perhaps?

 

Yes, get the part number for your injectors off the casing and contact the manufaturer for the data sheet. The datasheet will give you offset values for the injectors at certain voltages. Keep in mind that most injector values will come in mSec and our computers run in uSec so you will have to convert. Also, GM uses wierd voltage values like 6.4v, 8.2v, and so on while other manufacturers use 6v,8v, etc.

Here's what my datasheet looks like.

http://www.fordracingparts.com/parts/ics/m-9593-m39.pdf

 

Ok, I *think* I'm good. The set I got was for a Ford Lightning, and the one that was replaced was a replacement for a Ford Lightning.

 

What a conincidence. I also have Ford Lightning Injectors, but my set came from Ford Motorsports.

As long as the injector matches the basic design then the offsets should all be the same. The biggest problem I had was switching from the old Multec injectors to the Bosch III design of the Ford Lightnings. Do you have a cutom tune in your car?

 

Not yet but hopefully that is next!