nomad88z

So i've been planning a major overhaul on my 88 Z for some time now, basically new heads and cam, full exhaust, etc. my problem is that i dont' know whether i should keep the TBI and reprogram the ECM or just throw the ECM away and go to a carb. If i were to go to a carbed setup, would it be 100% mandatory that i replace my distributor? Also, what is the fuel pressure of a TBI engine? I have been told that carbs run best at around 5-8 psi, but i am unsure of the output of the TBI fuel pump.

Thanks guys

five7kid

iTrader: (14)

TBI runs a little higher, something like 9-12. But, you need a return-style regulator, because it's not nice to deadhead an in-tank electric pump (which is what the carb would do). 4-7 is more like the typical carb range.

Whether you stick with TBI or not is a matter of preference and requirements. The former being the trade-off between emissions-legality, fuel economy, driveability, & the like, and lower up-front costs and ease of modification.

If you go with carb, you may be able to stick with the stock distributor if you install an external TPS to the carb and maintain all of the other sensors - theoretically. I've never heard of anyone doing it, and I don't know for a fact that the ECM would be happy with no injectors to drive. It's been discussed for CC carb conversions, but again, I don't know of anyone who has tried it.

GuitarJunki17

iTrader: (1)

If you are looking at this swap in terms of ease, then you would want to go with a non-cc carb and a large cap HEI distributor. You can find them for fairly cheap, in the range of $60-$120 for a standard run of the mill in cap HEI. (Pro-Comp, Summit brand, JEGS brand).

For fuel, you can opt to remove the intank pump and attach a hard line hose to the pickup, and run a carb pump off the block, or you can do what many of us here have done and go with the Mallory 4309 regulator. It's not that expensive, and easiest to install. What I have found though (from my TPI system) is that I had to rig the fuel pump relay to stay on with the key on to keep the pump pumping at a consistent pressure. Why this is, I will never know, but I get a steady pressure now. Now all left to do is tune the carb to my application, which is probably going to be the most time intensive part of the process.