Hey guys,

I'm a new gen 3 owner and I'm in some dire need of advice. I recently bought a 92 RS as well as an 87 Z28(parts car). Both were owned by my late grandfather who sold them to my uncle about 20 years or so ago. I've been told the engine in the 92 came out of the 87 but I'm not really sure. Long story short the 92 has a 350 in it with an old Holley 4770 Carb instead of a tpi intake. Both cars have been sitting for well over a decade but after a new mechanical fuel pump, oil change, spark plug change, and flushing I got the 92 to run. I was told it was parked because the transmission was shot and never got around to being rebuilt.
I got the car running decent enough to get home and it's safe to say the transmission is for sure shot.

The real problem thats baffled me though is could the carb be too big? While running you have to very easily push the gas or it will flood and die. I tried taking the carb apart and thoroughly cleaning it but nothing changed. Several people have said to go down to a 600cfm carb while others have said my problem could be the adapter plate. I've also heard that there is an electronic fuel pump on the 92's but I can't seem to find it.

I'm still waiting for the transmission rebuild so in the mean time, I've been trying to figure this out while cleaning and painting up the engine.

Thanks in advance,

 

Electric fuel pump is inside the tank. Do you have a fuel pressure regulator to drop the electric pumps pressure (assuming the electric pump even works) to something the carb can actually use ?

 

The cup on the carb's accelerator pump(s) have shrunk from the additives in the fuel.
Work the linkage while looking down the carb (engine off). You will not see any fuel spraying out.
Replace with new pumps that are compatible with today's gasoline.

 

First question that needs to be asked (and no the carb isn't "too big"), is what is your goal with the car, and what is the budget for the fuel system?

GD

 

Additionally, after replacing the pump diaphragm, it is still possible that the discharge nozzle can be clogged and may need replaced.
I know this from experience...

 

It looks like the TBI harness is still there. Why not put the injection back on?

GD

 

I would like it to be a daily driver, I'm torn between tpi, tbi or a new carb. Budget is around $500

 

@GeneralDisorder
It is?? I would really prefer to switch it to tpi but I thought I would have to buy the whole system (about $250 used local) as well as a harness

 

Look for the ECU under the passenger side of the dash..... 92 RS may have been TBI, not necessarily TPI. In some respects the TBI is actually better and can support more power than the TPI can. Doesn't look as cool though.

GD

 

Seems to me the least expensive way out is to work with what you've got. It undoubtedly was a driver before it got parked meaning the fuel system worked to some degree. Follow up on:
At the very least you'll need to fuel pressure gauge for diagnosis. And that's something whether you stay carb or go EFI.

Make the sure you address all aspects of the carbs condition. Any rubber, despite having been cleaned, probably isn't up to the task of sealing.

This is also directed at the carb's condition.

That's another matter altogether.

You'll need tools regardless which direction you go. There are plenty of threads about resurrecting cars that haven't run for years and invariably they all have fuel system issues and for the most part all are almost entirely replaced. Tanks and lines flushed, in-tank pumps ( if applicable), filters, any rubber bits, etc.
First step, since you've had it running, assemble what you need and check the fuel pressure. THAT alone may dictate which direction you're going to go next. Carb or EFI both require specific pressures to operate so make sure that's sorted out. The rest can follow.

 

Thanks for all the input guys, I'll digest all this and see what I can work out the next few weekends!