I found out when pulling down my fuel rail to replace the o-rings that the PO had installed 24lb injectors on the engine. Looking at the casting number in the head the engine appears to be a 350 with 305 heads but I have not torn into it at all since I am trying to get it running for the time being. There is also a Hypertech chip in the ecm.

Is there anyway that the car will run without being incredibly rich with these larger injectors? When I had it running a little (fuel pressure issue) it smelled very rich. Also is there any way the Hypertech chip could be made for the 24lb injectors?

 

You want it to run or run well? If you want it to run well don't bandaid the car when all it needs is a simple tune. Sell the hyper tech and use the money to fix it.

 

I am trying to get the car to run well. the Hypertech chip was in the ecm from the PO, I wasn't sure if there was a possibility he could have put it in to compensate for the engine rebuild and injectors

 

Then just about everyone is going to tell you to ditch the hypertech and throw a stock "chip" and injectors in. You could just as easily get somebody to get you a tune with the injectors compensated for.

The hypertech should allow you to remove their chip from their adapter and plug in an injector modified eprom or stock chip easily.

Could be that the hypertech is for the 305 and they added 24#ers to compensate for the incorrect injector scaling. But that's an ugly bandaid I wouldn't want. Especially when a real fix is cheap/easy.

 

As soon as I can I am going to get the numbers off the Hypertech chip and see if I can get any information on it. I will look into getting a modified chip to compensate for the injectors. I wasn't sure if the old ecm could "learn" at all from the info from the O2 sensors

 

Yes, it can compensate in closed loop. Not in open loop. Hence the run or run well.

 

I see, that makes sense.