Hi, I'm new to the forum. I have a few questions about converting a TBI k2500 to a TPI setup. I already did a search in the forums and was flooded with posts that I couldn't really get any info from.

Anywayyyy.... I was wondering if i could could re-use my original TBI ecm, electronics, sensors, etc. on a TPI system. Seems to me it would work except for the injectors. Is there a way I could build an injector harness to mate up with the TBI computer? I'm thinkin similar to how edelbrock makes that TBI to MPFI kit. Anyone know how that works? Does edelbrock use special injectors? I would like to recreate that with a TPI system.

I wish I could get the edelbrock kit but its too much $$$.

Also, If i can't use my TBI computer, could I adapt a TBI unit to bolt up to the TPI upper plenum until i got the TPI injectors and ECM workin? I know it sorta defeats the purpose of a TPI swap, but it would help me keep my truck on the road during the swap.


Thanks! McKenzie

 

Welcome to thirdgen.org!

You can't use the TBI ECM, so find one '7730 (SD) and follow this article to repin your harness...I think there is also a repin article somewhere for the '165 (MAF) ECM

https://www.thirdgen.org/techbb2/sho...hreadid=216453

 

 

Welcome to the board and post your results and problems if any, were here to help.

 

Howdy....

I'm considering a similar project to yours, and here is what I've found.

A TPI switch will cost nearly the same as the Edelbrock kit. You will need to use an Fbody or Corvette Acc. Drive setup if you plan on using TPI because of the throttle body height. This is not the case with the edelbrock kit, as it was meant to work with your existing hardware. Both kits will require a new, higher flow, fuel pump. Intake routing in our trucks (mine's a C1500 5.7/A4) is not a problem, so if you want to go TPI, and you find a complete MAF system for a substantial savings over a complete MAP system, get it! You can always switch to MAP from MAF if that's really where you want to go in the future. Plan on buying all new sensors anyway, just to be safe. If you have a 350, plan on new injectors as well, as finding GOOD used 22lb units is a lot harder than the used 19lb units you would use if you had a 305.

The ENTIRE TBI system will be junked if you go to TPI. The edelbrock kit reuses the shell of the Throttle Body - so you aren't saving much there. The only thing you might be able to reuse is the harness if you repin it. Also, with the TPI swap, if you have a auto, you will need a new (longer) detent cable if it's a 700, and not a TH350. Also a new throttle cable may be in order (I never did find out.)

The total time for the swap should be about 20 hours with a decent working knowledge of SBC's beforehand. Have plenty of vac. lines on hand as well, because there's nothing worse than getting it all together and then finding out you are missing one line.

Some guys over at www.fullsizechevy.com have done both swaps, and it is another resource you might look into. I'm currently discussing my alternative TBI/MPFI idea with some of them, since there was limited creative support here. That having been said, once you get it all done, this the the board to be at for TPI specific questions and problems. I'm glad I bought my Fbody's before my truck because most members here are much more open and willing to offer constructive/productive suggestions and answers. Good luck!