1999 Honda Passport 1999 Honda Passport Difficulty Starting

I have a 1999 Honda Passport with 80K. For the past few months, it has been difficult to start. It will usually start up fine when the engine is cool, for example in the morning it will almost always start right up. No problem. It will also start right back up if I only stop for a moment, for example to pump gas. However, once I turn off the car for more than 5 minutes, if the engine is warm it cranks over several times before starting AND I usually have to hit the gas in order to make it start. It will sometimes start then turn off, or sometimes start then the idle will jump up & down & eventually return to normal. I also usually smell a gas/exhaust smell - no white smoke, no smoke period. I have no complaints while the car is running. It seems to drive fine. I took it to a specialty import shop & they couldn't figure it out. Their advice - Bail (it may need a head- not sure & they didn't want to mess with it, since another mechanic fixed the head gasket but if it does need a head - you can't find one I was told, AWESOME) ALL of my fluid levels are fine. Parts recently fixed/replaced: Head gasket, intake gasket, fuel injector, fuel filter, water pump, thermostat, clutch fan, flex pipe on exhaust-there was a leak, timing belt, drive belt. No lights are on, besides my ABS. No check engine light, no codes. However, There was a problem at the machine shop (which I know - never happens) but it did. The cams were taken out & since they were hurrying, were put back incorrect. After about a month my mechanic figured it out & it was corrected. I am told it still could be shimmed, that there is possibly too much gap in the lifters? It does cause a slight noise. I don't know, But they do not seem to think it is causing the starting issue. This car has been a nightmare.I see there are some other posts on here almost similiar to mine, but they do not have responses. If you have any ideas, I'm open. I bought this car so I could go back to school & NOT have a car payment & unfortunately my repairs are more than my car payment was for my VERY reliable car.