Stalling out after throttle body work (from a novice)


New Member
1985 T-Type
Hey guys, I had an issue where when I would start the car it would run at oh, 1300rpm? If I let it warm up and restarted the car it would run at 1000. A mechanic suggested I swap out the IAC. So when the part came I decided I would remove the throttle entirely and clean it.

This went well, and I made sure to cover the TPS to not get carb cleaner on it. The old gasket material between the throttle body and the turbo all stuck to the turbo side and the throttle side was easy to clean up. The turbo side took a lot of work to get clean, and there’s still a bit of dark residue near the studs that I can’t get off, but I can’t feel it with a finger, so hopefully it’s not enough to ruin the seal.
O’reilly only had the fel brand gasket in stock and it was way off on size. I’m sure you all already know this. I ended up trying to make my own gasket out of rubberized paper material, but I used the throttle body as the template, so it’s got a lot of overhang compared to the turbo side. And the center hole isn’t PERFECT, but close.
Anyway, I got it all back together and now the car starts and stalls out within a few seconds. I’ve replaced the worst of the vacuum lines from the vacuum block with silicone hose. I replaced the two heater hoses on the bottom of the throttle.

It does sound like I can hear an air leak somewhere, and I’m guessing it’s due to the gasket I made? The biggest mistake I made was the gasket in the vacuum block, which has a flat side and a ridged side and I don’t know which side faces up, but I assume the ridged side faces up. I tightened the block down a bit tighter after the motor failed to keep running, and it did run a little longer before stalling out.
I’ve ordered the aluminum block from gbodyparts and may just replace all the lines on it as well.

My MAIN question is whether anyone knows where I can get a proper gasket for the throttle to turbo comp connection, or, if I need to make one out of a different material or RTV, etc.
I also was hoping anyone would have some advice. Another note is that I put the old IAC back in as an experiment and it seemed to run a little longer before stalling. I’ve read on these forums that those AC Delco valves can be hit or miss.
The car was running fine before I did this job.

Sorry for the novel, just figured as much info as possible would be helpful.
Thanks for putting up with a novice who just wants his car to be what it was meant to be. I can share pics of anything if anyone thinks it would be helpful.


Grumpy, Greasy, Old
Sorry no one has tried to help. Are you trying to just let it idle? Will it stay running when you give it some throttle? Does it rev up? If it will stay running with a little throttle, you could have a helper hold the throttle where it stays running and you could pin point the vac leak by carefully spraying a bit of carb cleaner at the different hoses and connections. When you find the vacume leak it will speedup and run smooth for a moment. Then you can concentrate on that spot until you repair the leak.


Tall Chinese Guy
There *could* be multiple issues going on, which is why the data from a scantool is critical to get help online. For starters, since you only worked in the throttle body, and the car ran fine before (?) the basic questions would be;
TPS value is?
IAC value is?
Idle BLM is?

Unfortunately, you will need to make a gasket. The temp can get pretty high (~200F) so use an appropriate material.