Odd Starting Issue

[ugly mx6 guy]

I have a strange and frustrating problem that started yesterday. I removed the plenum and throttle body to fix a coolant leak from the hose on the bottom of the throttle body. I got that fixed easily enough. But when I started the thing up after I got it all back together, the engine revs really HI and then dies. I checked everything I worked on and found nothing wrong visually. The only thing I knew to do at that point was to take it all back apart and then put it back together again making 100% sure I was doing everything right. I fear that it will just do the same HI revving thing again and then die. The only thing I can think of is something TPS/Throttle Body related that I knocked out whack somehow. I can't really see how that could happen though, but I am out of ideas after that. I did think about changing over to another throttle body I have to see if the problem is there.

Thanks for any help.

John

[Leev]

Here's my opinion:

The IAC is very finicky and even then, can just stop working for no reason. If there are pockets of air, or low coolant, it will start to hassle you.

Did you top the coolant back off when you were done, and burp the coolant? I mean REALLY burp it.

Like.. really, really burp it.

Other than that, make sure the 3 sensor connectors are plugged in correctly (TPS, IAC, Idle switch((name?)).

Also, a really bad vacuum leak will make it rev high and die. It would have to be pretty obvious though.

[ugly mx6 guy]

Thanks Leev for your suggestion. I did lose a little coolant when I pulled the throttle body hose off. I would bet though that it did not amount to more than a couple of shot glasses worth of it though. From reading some similar stories online, it sounds like I have a significant vacuum leak somewhere. It has to be in the vacuum nest behind the block or maybe around the throttle body. Oh well, back to the drawing board.