I have recently rebuilt the engine and factory Rochester carb on an '86 Iroc, but am not very happy with the carb's performence - would like to just rip it out and drop in a new Edelbrock (non-computer). Anyone have any advise?? What effect will this have with computer and how can I get around any inout from the thottle position sensor, etc.

 

It'll throw the computer into "limp home" mode when it sees there is no connection to the original TPS or Mixture Control Solenoid. THis, among other things, will cause the ECM to supply a very weak timing advance curve to the factory computer controlled HEI distributor, killing any chance of good performance even with a properly functioning carb.

You need to replace the distributor with a non-computer controlled one at the same time you change to a non-computer controlled carb. Then yank the bulb out of the check engine light because it will be on constantly. You will also have no lockup function from your torque converter (assuming original 700-R4 automatic with stock lockup style converter) since it won't have a TPS to reference any more.

Last, a FACTORY QJet intake manifold will need an adapter to fit any other kind of carburetor onto it. It's got throttle bores that pecisely match the throttles on a QJet- it;s not jsut a big open area below the carb like, say, an Edlebrock Performer intake is. Nothing else will line up properly without an adapter.

 

Thanks for the info - if I choose to keep with the original Rochester design, do you know of any quality rebuilders? I have gone through the basic rebuild (float, float valve, gaskets, cleaning, new MSC) but beleive that the throttle valve shafts are worn, etc. causing irratic idle. would you recommend a different carb, adapter plate and distributor or keeping with a "good" factory Rochester?

 

Go with a non CCC Qjet and a mechanical advance distributor.

Martin

 

If you are gonna go that route, you might as well get an aftermarket lockup kit and rip the ECM and 1/2 the wires out of the car too.

- Justin