I have a 305 TPI motor in my car. If I were to buy a 350 TPI motor that is missing the entire TPI system, what would I have to do to get the 350 to run correctly if I put the TPI unit on it from my 305?

 

change the knock sensor, change the prom (memcal) in the computer, change the injectors to 22lbs. there might be a couple more little thing, but I can't think of them right now.

 

I think that sums it up.......

 

Zepher told you the right way to do it, but if it is a stock 350, and since yours is an 86 with a MAF system, you can get by with using the 305 injectors and chip along with an adjustable fuel pressure regulator to add a few extra pounds of fuel pressure to compensate for the extra cubes.

 

I kind of have to laugh. I was about to post a similar question as I have an 87 formula that was originally a 305 TPI. It now has an unknown displacement motor in it because I KNOW the motor isn't original (perimeter valve cover bolts rather than Center bolt valve covers). It doesn't run at this point.
The previous owner said that it could sort of run when he crimped the return line. Crimping the return line may have increased the pressure enough to make the injectors work.
I was thinking fuel pump was an issue until I remembered the above little tidbit.
he also said something about it running worse once it warmed up.
I'm now thinking it's just wrong injectors.
Anyone have any thoughts or suggestions?
preferably cheap ones, I'm selling the car at this point so popping a new set of injectors into it isn't really an option. If ones from a year other than 87-88 will work without modifications, let me know.
For testing purposes I could probably grab a set out of the 89 IROC temporarily, but I'd rather not do 2x labor and hopefully someone will buy the IROC soon.
I'm getting out of the project car game.
Oh, if anyone is looking for a 3rd gen we (my brother, me, and my uncle) have 3 for sale and 1 2nd gen.

 

Nothing really if you have a near stock moter. That is the setup I have on my car. LB9 top end with a 350 short block. The car only ran good once and awile when it ran good it felt just as strong as my 96 lt1 ta. But I got my car out of a feild like it is. It ran good for many years. Untill the previous owner got it. now Im picking up his mess.

 

See what "chip" is in the ECM - check the numbers to see if it is still the 305 or if he put in a 350 chip and used the 18# 305 injectors. If it is a 350 chip and 305 injectors,, it'll run lean. If that's not it,, clogged injectors, bad regulator,,, bad fuel pump,,, could be one or a combination of things.

 

If it runs better with the return line crimped, perhaps your fuel pressure regulator is bad, and not letting pressure build up... Crimping the return line would then increase pressure again... I'd look at the regulator first...

 

I think the ESC module is different as well as it's setup for which KS is used.

 

Its working on my car so far. I have an LO5 block & heads with the stock injectors and TPI system from my 86 T/A. I'm going to dyno next saturday to see where the AFR stands.

So far as it is I got a best 1/4 mile time of 14.4 @ 93mph with a 1.90 60'.
The rear end is the stock Australian 9 bolt with a 3.0 Gear Ratio.

 

Pressure regulator is new. one of the many parts the PO threw at it.
I'll have to check the chip, toss a fuel pressure tester on it something I should have done a long time ago. Maybe I'll run some FI cleaner through the system.
of course if it turns out to be the fuel pump that is how the car will sit until it is sold.
too much work to replace it IMO