I have an 1986 Trans Am and i am taking out the old 305 and putting in a 350 but using my old TPI set up. Someone told me that i would need a new chip when using bigger fuel injectors like 22 or 24lb. What kind of chip? Where can i get one and how much would this cost me? Thanks!

 

I called the pontiac dealer and they said i need a new ECM for a 89 Trans Am 5.7liter TPI. Is that right?

 

Anyone???

 

That's bull because 86-89 used the same ECM 305 TPI or 350. The chip or EPROM is different, though.

 

What kind of EPROM would i need? One from a 89? How much are they and where could i get one?

 

You say you are using the TPI from the 305 so I assume you are using the 305 injectors. If that's the case you don't need to do anything. A MAF car doesn't need to know engine displacement. If you are using the bigger injectors, then you need a prom from a 350 86 TPI car that has corresponding injectors in the prom as well as in the TPI. In either case, the BEST thing you could do is use the code from a 89 350 car and burn your own proms for best results. You can't use the 89 calibration unless you burn your own proms because things like the fan and VATS need to be played with for them to work right. And like the previous post said, the 86-89 ecms are the same, they just came with different calibrations.

 

If i kept the same injectors (19lbs) will it still run and perform good? I was thinking about getting 21lb injectors (Stock injector, according to Pontiac dealer) but dont know where to get the stuff. I called the dealer today asking for an EPROM for a 89 TA with a 5.7. he said there is only 1 for that engine size and only one PROM for that car. Is this right? Was that the PROM i need to run bigger injectors? They are asking $63.71.

 

I came across this website after doing a search and saw all these EPROMs. EPROMs This is what is different in doing a 305--->350 swap with bigger injectors? I want to get 21lb injectors. Which on of thes would i need? Can I get one at a local store cuz i dont want to have to order it off the internet!

 

Anyone?

 

Yes, this is the best it'll run without prom burning or other custom methods. The proms you saw on those sites are not plug and play so forget about it.

 

22# fuel injectors are STOCK for a 350 NOT 21# Just for your info.
And you will need a new chip to run the 22# injectors, and since
you are using the 86 TPI with a cold start injector, your besr bet would be a 1988 Stock GM chip fpr the 350. Chevy/Pontiac engines are the same and use the identical parts. Also using the 19# injectors on the 350, it will run but not at its best. Why go half way? My opinion.