Alright so this is a 1989 Trans am GTA 305 LB9 originally but now has a 5.7 193 Swirly head bottom end and the top end of the original 305. All done from the previous owners. The last owner that my friend bought it from removed the A.I.R system and A/C. We are putting back the A/C but not the A.I.R system. When we purchased the car it idled very high around 1500 warmed up and around 1100 in drive. We have tried getting it to idle lower and more normal which have come up with problems. Unless it idles high it will struggle and sometimes stall. Right now after doing some work to it, it idles at around 1000-1100 rpm and 750~ in drive. Right now it will like to struggle in drive and fluctuate around not something crazy but very noticeable. Idling in park its very steady and no problems. The tps is currently set to 0.54V and the IAC was bought new. EGR tested out fine.

A few days ago, it was throwing Code 34. I gave the MAF a inspection and bought the cleaner for it and the code is now gone. Everything seems to be working fine so we have ruled it to be a Vacuum leak. Right now the car will not run without having the port labeled as ''Air'' on the canister plugged up. Before when running with Code 34, the plug would have no affect at all. The following picture is how the car would be set up normally but the line going from the Solenoid to Throttle body was cracked and running without it and the hole is plugged on the throttle body at the moment.





So my questions are:

-What is supposed to be in that T plug that is in between the connection to the plenum and to the vacuum ball?
-Is the plug labeled as ''Air'' supposed to have any hose to it or it routed to somewhere?
-Are the 2 lines that go to the EGR Solenoid ever supposed to be merge besides into the selenoid? Meaning the one that goes to the actual EGR and throttle body. Also what is the order of it if your facing it from the front? EGR bottom throttle body top hole on the selenoid?



Is anything wrong here? I forgot to add the hose to the booster but that is connected, sorry.


Also another question is about the knock sensor, I am sure it probably has the original TBI knock sensor for the harness the 5.7 bottom was from. Would this cause problems? I figured I should bring this up since I know when going from 305 TBI to TPI its a required thing to replace.

My last question is about Oil Pressure, What should be the oil pressure the original 5.0 LB9 and 5.7 L98? Right now the oil pressure of the car is high and is always near the highest point of the gauge.


Any help would be great, pictures of your 305 tpi engine bays (stock bays) would be even more great

 

T should be a one way valve on line to vac ball to prevent loosing vac when you accel.
Rear port of valve goes inside to control vent position, side port goes to vac ball and Tee's off to cruise control on the way ( if fitted )



Knock sensor must match engine
5 different ones ,each setup for a set combo
305 TBI
305 TPI MAF
350 TPI MAF
305 TPI MAP
350 TPI MAP