My car starts and idles rough 400 rpm to 1500 rpm goes up and down and then dies out.

Check engine code, got 22 replaced TPS and adjusted to specs the old one was shot no changes when trying to adjust.

Car starts but does the same thing.  No 22 code after new TPS was installed.

A member suggested to change coolant temp sensor, Got a Delco newer style one, install and still have rough surging idle.

Check for codes, Only flashes 12 12 12 ETC..

I can hold the throttle to keep engine running.  TBI spraying a nice umbrella shape fuel pattern,

but once throttle is release TBI sprays very little fuel and engine dies out.

Vacuum for the headlights goes up and down without a hitch, trying to rule out vacuum leak.

Any other suggestions and advices is appreciated.  Thanks.  Trying to get the Corvette ready for the summer.

Without more info, or live engine data(from a scanner), I would suspect the Idle Air Control valve. The Crossfire set-up takes a special "tool" to plug the air intake passage while the AIC self adjusts. It could certainly be a vaccum issue also. Has the car done this for a while, or did it just start, and throw the 22 code for the TPS? You might try disconnecting the battery overnight, and then start it, and give it time to relearn the idle. I can look in the Factory Service Manual and see what the process is, but I won't be able to post it until tomorrow. As an owner of an '82, I would also highly suggest you get a Service Manual if you plan on doing the upkeep on it yourself....they can be quite cantankerous! 

Sounds like how my 87 IROC Camaro did when the fuel pump was going out.  If you don't have one, get a fuel pressure gauge at Home Depot for about $25.

It just started to happen, started it up last month and it ran fine, when I start it 2 weeks ago all this happen.  Where do I connect the pressure gauge to test fuel pressure?  Looking at the set up and can't figure it out.  Did a search, only see custom piping set up to test.  Any suggestion is appreciated.  Thanks.

Where do I connect the pressure gauge?  Thanks.

On my IROC, there was a Schrader fitting on the fuel rail.  Of course it was a TPI system whereby yours is dual TBI Cross-Fire setup.

Checking fuel pressure requires a "special tool" that replaces the fuel line that connects the 2 throttle bodies, allowing a gauge to be installed. Attached is the chart for checking the IAC system. 

Thanks for the reference page.  Reading the 1st block idle engine and record RPM in park or neutral, RPM is erratic surges from 400 RPM to 1500 RPM and dies out.  Don't know how to go farther if I can get pass this 1st step.  

I have so much to learn and figure out.  I guess I should find some way to test the pressure first before moving ahead.

Thanks for the help.

Here is a video link to show what the car is doing...

https://youtu.be/cgBwKQ3AMqk

Thanks for the help

The guys in this thread may have some helpful information.  There is also a link there to a TBI specialist site.

https://www.corvetteforum.com/forums/c3-general/4538608-my-crossfire-16146299-ecm-odyssey.html

This is an update of my on going work in progress, I rebuilt the TBI with ACDelco OEM rebuilt kit, also install IAC OEM ACDelco part.  Car still idles rough and dies out.  But after restarting the car a few times, the car lose all power, when you turn key, no cranking, no sound.  I disconnect the battery and connect it back, it would start again.   But again after a few start up and die out, no power or cranking again.  Disconnect battery and start all over again.  Or let it sit for 5-10 minutes and it can be started again.  Is this leading to a bad ECM?

Still trying to figure out a way to check fuel pressure.  This is getting discouraging.

Any help or advice is highly appreciated.  Have an attachment of a video on post above to show how car runs and dies out.

Thanks