Thanks! I'll see if I can borrow my friend's temp gun. I did a smoke test through my brake booster line and found some smoke coming from the driver side where the throttle body. connects to the intake manifold. I'm going to replace the gasket, retorque and also replace the rubber elbow between the TB and MAF. Then I will smoke test again. I haven't checked any vacuum back near the EVAP cannister, but I replaced all those old crumbling rubber hoses and the EVAP cannister when I pulled the tank out to swap the fuel pump and sender.

 

You only need to test the EVAP purge solenoid connection from the canister, to insure it is blocking the vacuum from the intake manifold when not energized. If the EVAP solenoid is OK then test the line/elbow from the solenoid to the throttle body.

 

Solenoid and both lines are good. I'll swap the TB gasket when it comes tomorrow and retest this weekend. Thanks!

 

I swapped out the TB gasket with a fel-pro and replaced the intake boot between the MAF and IM. I also replaced a small piece of vacuum hose coming from the EVAP cannister on the driver side of the IM that I missed before and was a little crumbly. I ran another cold start log this morning and it still looks like there may be a vacuum or other source of air getting into the IM post MAF. I'll keep searching for leaks.

 

I hooked the smoker back up and now I can see where I have a large vacuum leak. The throttle body plate shaft seal is leaking badly on the side where the throttle cable attaches. Not sure if the TB is rebuidable or the seals replaceable, but there is a good amount of smoke coming out which would explain the IAC numbers. I'll pull the TB and see if there is some kind of rebuild kit. Otherwise, opinions about the best option for a replacement would be appreciated. I have a stock motor so don't think I would benefit much from larger bores. Thoughts?

 

Thought I would post a follow up and let you know the issue is resolved. After chasing a few vacuum leaks, replacing the optispark with a Petris (because coolant fouled it and threw a DTC16/36) and finally replacing my 200k+ Random Technology cat with a new Magnaflow cat, the old girl passed smog with flying colors. Was having issues with high NO.

Thanks to Injuneer and others that looked at my scan logs or offered advice. Nice to have her back on the road.

Dave

 

Thanks for the followup. Not everyone does that.

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