Hey everyone,



I’ve got a 1992 Chevy Camaro RS 25th Anniversary with the 305 small block and TBI fuel injection. Lately, it’s been giving me some trouble, and I’m hoping someone here might point me in the right direction.



Here are the symptoms:

• The car will sometimes stall when I’m coming to a stop or idling.

• A few times while driving, it stalled and I had to restart it.

• Occasionally, it bogs down like it’s struggling for fuel or air.

The idle will be ok then will start to go down really quick and low and jump back up fast and will keep doing it then when I rev it it will smooth out and then if you wait a little bit it will start doing it again.

Has anyone had similar issues with a TBI 305, or know what I should check first? Could it be something like the IAC valve, fuel pressure, or ignition-related? Any advice would be appreciated.



Thanks in advance!

 

Check engine light on ?

 

Yes I think so

 

and the stored code or codes are ?

 

I didn’t know you could check codes on obd 1 port but when I get them I can tell y'all.

but it just started doing it wile driving I was told.

 

https://mechanicbase.com/trouble-code/obd1-codes/

 

Thank you

 

So I checked and when I started the car there is no check engine light it comes on when I first turn on the car then when I start it it turns off

 

This is a video or sound of what it’s doing

 

I just checked all the codes and the code 21 was on so I’m about to replace the throttle position sensor

 

I would check the voltage sweep on the TPS before changing it plus you probably would want to know what the TPS volts are at closed throttle.

Have you checked fuel pressure?

 

No idk how there is no fuel rail

 

And another question do you have to relearn the tps if so how.

 

Thank y’all for all the help I appreciate it all to.

 

Light comes on with key in "ON", engine off = Normal, bulb check

Light goes out when engine starts = Normal, means no active codes (no faults happening at this moment)

Found code 21 = That's in system memory (otherwise the light would be on now), which means it saw an issue in that system at one point in time. Note it's the system...could be it's adjustable, but out of range. Could be a corroded connection, a wire chewed by a mouse, etc. It does not instantly mean a bad sensor, though it could be that.

Agree with the above....knowing the voltage with the throttle closed, and at Wide Open Throttle (WOT) would be a start. Watching a volt meter as you move the throttle and watching for a smooth change in voltage with no big sudden jumps or dead spots would also be helpful.