Ok so i have a 92, z28, 305, manual. I recently bought this car and was doing a tune up when i noticed a vacuum line from the throttle body to the Evap canister was not hooked up. I thought it just slid loose, ill put it back on and tighten it down with a zip tie. Now my car wont start. I unhook the line and it fires right up. If i leave it unhooked and plug it with my thumb or put it on the canister while the engine is running it dies out immediately. The line is not clogged, and i can suck through but not blow through the line going back to the fuel tank. If i hook power and ground to the plug on the canister i hear the solenoid click and i can blow through it. I used a test light across the plug (key on/engine off) and there was nothing. If i hooked from the power wire to a chassis ground it has fire. So do i have a bad ground wire to the plug or does the ecm only ground that when it sees fit?

 

only grounds it when needed. it runs unhooked you say? meaning a vacuum leak? thats the way i read it. inform if not, but if i read it right then reset your min idle air setting. good article on here that explains how to do it. it sounds as tho the solenoid is working correctly tho.

 

And yes you read it correctly. There is a vacuum leak, and if i plug the leak it kills the engine. Thats what made no sense to me, usually if you have a vacuum leak the engine wont idle rite, but mine seems fine, and normally you plug the leak and the engine will idle properly this one just shuts off. I dont get it.

 

OK I have another question. Is the 92 TPI a self learning IAC? If I unhook the battery for a while and then hook up the vacuum line and then let the IAC relearn its settings. Would that possible work???

 

read the minimum idle setting procedure. itll explain it all.