First, please understand I am not there and will answer these questions to the best of my ability based on experience and our conversations.
First, if the gasket is leaking, you should be able to replace it and it should be fine. If one section of the intake is cracked and the other is good, replace the bad section. Why replace a good part. As far as the job, because of her schedule, I feel it became noticeable.
If it is a sensor, the check engine most likely would have come on indicating a code for a particular part. Also, yes other vacuum leaks can cause a hard start situation.
I hope I answered your questions. As I mentioned, it is really hard when I am not there to actually see the problem, but based on what we discussed, I gave you the best answers I could.
Please let me know if you have other questions and how things work out for you. If feel confident that if you were to call another mechanic in your area, they would tell you the same thing. I just hope the people where you have it have correctly diagnosed the problem. It concerns me that they were ready to replace the engine because of an intake gasket. That really isn't normal protocall unless they know something we don't.
Take care and good luck,
Tuesday, March 10th, 2009 AT 9:19 PM