1987 Monte SS Carb swap

[85_SS]

You are getting codes, correct? If you aren't, then there are other problems to address. Without a reference from the TPS, the ECM has no idea how much throttle you are applying, which isn't a good thing. You would be much better off going with a vacuum advance distributer - it just doesn't make any sense to want to run half of the system. As I say, it will run, but it isn't running optimally - the ECM is throwing codes for a reason 🙂

 

[megaladon6]

don't know about the codes as the light is disconnected, it's not something i need. i'm sure they're there but if it ain't broke don't fix it.
even if i had the carb there it wouldn't run "optimally" it's a 383 not the 305 the ecm was programmed for. same thing with vac advance, it's not "optimal" unless you modify it via the vac adjustment, springs, and bushings.
and the ecm doesn't NEED to know the tps position for the advance. it helps yes. with large throttle changes, which my car has no problems with. what the ecm goes off of is load and speed. which it gets from the MAP and BARO sensors and the dist/tach pulses. without the MAP signal it goes off of a base curve and it can still see large load changes by speed and adjust for them quickly. in other words it works fine. some people have even retro fitted the system in to their (originally) points and condensor based hot rods with just the ect and knock sensor.
think about it, the vac advance dist don't have a tps sensor. and the vac port actually acts as a retard under low load/high vacuum situations. so it just reduces the timing to prevent knock. the electronic dist uses the knock sensor to reduce timing if it goes too far.
oh and you do need to use a f or g-body HO computer. the max advance on the regular units is abysmal. the HO units give something like 30* total.

 

[85_SS]

Unless you scan it on a regular basis - you'll never know if it's broke and in need of fixing 🙂 The CCC system is not very sensitive to differences in displacement at all - it simply adjusts mixture to constantly try to obtain the 14.7:1 ratio at the 02. Plenty of people (myself included) are running a completely stock system on a 350. I swapped in the 350 ESC module and knock sensor, but even that isn't really necessary. You can even use the system on a BB if you want to burn a custom chip for different advance curves.


Sounds like it's working for you, just not the way I would go about it running bits an peices of a system that is designed to work together. Nothing wrong with a good ol' Q-jet (especially a CCC version) for the best mix of both worlds in performance/driveability and mileage 🙂

 

[megaladon6]

i'll know it's broke when it runs wrong and then i'll diagnose it just like any other problem.
my point is only that the dist can be used without the carb. i like it simply for the knock sensor. it's an added saftey factor.