I just finished putting in a new motor in my '91 Trans Am. Its 350 block out of a '96 3/4 ton truck I put my 305 heads on it and opened up the combustion chambers and added 350 exhaust valves for it to breath a little better while the motor was out I replaced all the seals and gaskets as well as the spark plugs, cap and rotor, headers,and a header back exhaust. I'm still running the 305 fuel system in the car until I can find some of the 350 stuff.

The car was hard to start at first but once we got the air out of the fuel lines it starts up fine but has a rough idle to it. After driving it around for 20 minutes or so the car just shut off on me kind of like it was running out of gas. It was really hard to start back up again. I let it cool off but I couldn't get the car to idle with out having to keep my foot on the gas then once I got home and went to shut it off it was idling fine again. I pulled the codes and its showing up as 32 (EGR) and 43 (ECS).

The EGR code is throwing me off a bit because I don't have the EGR system on my car any more and haven't had one on there for about the last 7 years, way before I replaced the motor and it never threw this code before.

I've also disconnected the knock sensor and reset the computer but the codes still show up.

Ohh yeah and the intake gets super hot.

Any suggestions is a huge help.

Thanks,
Steve

 

Alright I was able to get the code 32 to go away but I'm still trying to clear the code 43. Any ideas on how to determine what is causine the code when I looked up what could cause this code in my Hayes book it left to possiblities pretty open.

 

Are you using all the TPI intake parts from the 305?
Are you using the 305 ECM and Chip? I'm assuming you are.

 

yes. I'm still using all my 305 stuff.

 

You need to hook up the knock sensor from a 91-92 350 tpi f-body car. The computer needs to see a signal from the knock sensor right after startup. I had been fighting this problem with my 91 Firebird Formula, it had an engine from a 88 Formula and had the wrong knock sensor in it. When this code is set, the computer limits how much timing is advanced since it sees a fault with the knock circuit.

 

I guess thats my last option because I've replaced the ignition module, IAC, and coil with no luck, in fact I ended up putting my MSD coil back on because it ran worse with the original. I've also checked to grounds too.
----------
I guess thats my last option because I've replaced the ignition module, IAC, and coil with no luck, in fact I ended up putting my old MSD coil back on because it ran worse with the original. I've also checked to grounds too.

 

I put a new knock sensor in it and so far so good. I still need to figure out why it occasionally dies while idling. I thought the newish IAC would have fixed it because the old one was making all sorts of noises.

 

So a new knock sensor solved your code 43? I just got a code 43 this morning, I just finished an engine swap recently and am chasing a few gremlins.

 

Yeah I diconnected the battery and put a new knock sensor in it, hooked everything back up and the code was gone. Now all I have to do is get new spark plug wires that don't rest on the headers an melt.

 

Thank you, that looks to be my next step with this thing.

 

Did this solve it for you as well?

 

I won't know until tomorrow, it's Christmas day - no parts stores open today.

 

Finally got around to replacing the kock sensor, seems to have solved 99% of my problems. The code 43 is gone, and the idle is 10 X's better. I still have a slight off idle stumble to address though. I still need to verify where my base timing is and set the minimum air - see where I stand after that.

 

305 and 350 exhaust valves are the same size, 1.50"


You've been lucky then, as the computer checks the EGR circuit for operation once its in closed loop and you're travelling down the highway. Perhaps when you installed the new engine you missed a wire?

The computer needs to see the correct knock sensor when it starts up. Disconnected knock sensor equals code 43.

Intake gettting super hot means the EGR valve or its passages are stuck open, and you're getting hot exhaust gasses into your intake tract.

I know some of your questions were already answered but there's my two cents.