Fatdog2

I just watched U-TUBE about Multec fuel injectors.(Fuel injector connection)Scrolled down to multec and watched the testing.I didn't realize I was suppose to check the injectors when the engine is hot as well.I'll check mine soon.Anyway,mine are 22lb. and I wonder if there would be an issue running 24 lb. injectors? Would any changes need to be made or will the car adjust?Many thanks for any input.

Injuneer

Every time the 24 #/Hr injector pulses, is will flow about 9% more fuel than the ECM thinks it is flowing, causing a rich condition. In closed loop at part throttle, based on O2 sensor feedback, the ECM will adjust the long term fuel correction (BLM) below 128, subtracting the fuel by reducing the pulse width. So, in closed loop, no change.... UNLESS the ECM is already operating with BLM's below 128 for some other reason. The maximum fuel the ECM can subtract using the BLM's is 15%. So could remain running rich. Not good.

Then you go wide open throttle, and things really get screwed up. Since the ECM was subtracting fuel in closed loop, the ECM ignores the BLM, and you are running very rich. The big problem with the LT1 factory tune is that it's too rich at WOT, probably to play it on the safe side and avoid detonation. Typical target A/F ratio in power enrichment mode is 11.7:1. Peak power requires a leaner 12.8-13.2:1. But the 24# injector results in a 10.7:1 A/F ratio = even more lost power, wasted fuel, maybe rich enough to wash down the cylinder walls.

That's the long answer. Short answer is "no", not a good idea. If you change injector size, the injector flow rate must be changed in the ECM program, in the case of your 93, requiring a new chip. And using a larger injector, even if you do change the program, will not change power.

Fatdog2

Fuel Injector Connection offers two different sets of rebuilt injectors for my 93.
One set are made (Bosch 3) for 1986-1992 Camaro Firebird,corvette 22lb.
The other set is for 1992 Corvette only using identical specs as stock but have a 4 hole discharge for better performance.(Bosch 3)These will not work on any other Corvette years.Any thoughts on these? Many thanks in advance.
Also the higher performance are a straight forward install.

Fatdog2

Well,I bought the 22lb. injectors made for 1992 Corvette only(same as my 93 engine I'm told).I'm going to install them Monday.Will post results.I've been chasing down a small vacuum leak that GaryDoug picked up of my last 93-94- scan.(rough idle).I have vacuumed checked everything on the car(except the line from the purge valve to the canister)I did check the tube from the purge valve to the connector on top of the engine where there is a small connector going to the canister.I checked every hose,solenoid,valve(in the back to),fitting,everything holds vacuum.I bought a party smoke machine from e-bay,hooked it up to the power brake booster hose and let her rip.After 5 minutes or so the only smoke that showed up came out through the plug I put in the air bellows for my iac relocation trick.Nothing came out of the manifold,throttle body linkage or gaskets,valve covers,nothing.I did pull the injectors out and did the utube injector cleaning with the 9 volt and glass jar thing and they all sprayed evenly.I did notice that every time I throw a bottle of chevron injector cleaner in the tank,the idle will smooth out somewhat for a while.I'll post results soon.Thanks for reading.My02.

Fatdog2

And the brake booster is ok because when I pulled the valve off it went shoosh,vacuum.

Fatdog2

Ok,installed the new refurbished injectors today.
Disconnected the battery.
Pulled out the old injectors.
Installed the new ones (22lbs.)
It took about 2 seconds for the car to readjust to the new injectors.
Had a higher idle than before but leveled out.
I let the car idle for 15 minutes as per instructions watching for leaks with a fire extinguisher by my side in the driveway.No leaks.
I do have better throttle response and I don't need to press the accelerator as down as far as before while driving.My cruise control konked out during the whole drive (50 miles up to Ventura and 50 miles back.).When I got back I checked the cruise control fuse ,it was ok.Check around where the cruise cable goes and it looked fine.Had my wife check my tail and brake lights and sure enough the third light was out.Popped the cover and both bulbs(new last month) were broken.I mean white hazed out and glass broken on both.Replaced both bulbs,went for a run,cruise works now.
The car starts in less than half a second.
I found the best band aids are the BAND AID BRAND band aids as they cover up the sliced meat on the arms real well.Not like the dollar store kind.
Bottom line the cars does idle smoother but I still occasionally have a not so pronounced rough idle.So the search goes on.My02.Hope this helps somebody.

Fatdog2

Fuel injector connection.Thumbs up.See them on U-tube.