Just got my engine put back together and got it running....got crower stage2 cams and valve springs, obx cam gears,intake,full exhaust. Now i got it finished and it started right up. So i let it run for a little bit to make sure nothing was leaking. Well i shut it off and went to start it again and it would barely start it would fire up hit about 500 rpm and shut right back off. So i hold the gas in it fires right up but it will only stay running with my foot on the gas and when i rev it it feels like fuel cut at 4 grand thats all the further it will rev to....Pulled the codes got P0108 any help would be appreciated...thanks

Did you look up the code? What is it?

How much vacuum are getting at idle?

Additionally, on a fresh build why are you revving it to 4000 or higher attempting to find the fuel cut?

yeah the code is for high voltage at the map sensor and high barometric pressure i think...but i was tryin to keep it runnin i wasnt tryin to find the rev limiter lol...and i think im get 15 psi of vaccuum not sure i have a shitty vaccum gauge...

also when im holding in the gas to keep it runnin as soon as i let off the gas it just shuts off. No studder or anything just shuts right off...

Very vauge analysis here, but it sounds like its getting too much fuel and/or not enough air. Try replacing your map with a known good one, maybe borrow one of a fellow DSMer.

Also make sure your TB is properly adjusted.

what kind of info you need?

replaced map sensor and it still only stays runnin with the foot on the gas and as soon as i let off its like i just turned the key off its just shuts off......anyone have any ideas?

Might want to try pulling the IAC and thoroughly cleaning it to make sure its not sticking. Also, make sure that your TB plate is properly adjusted as I stated in my earlier post.

ok changed tps and iac and it still wont run. If i keep my foot on the gas i can keep it at 1000 rpms to idle but as soon as i let off it still dies. I am still gettin a code for high voltage map sensor. If i dont figure this out im takin the car back to stock. any help would be great...thanks

Pressurize the system and look for air leaks. Could easily be a vac leak.

Also, check to be sure your timing correct.

I actually had the exact same issue a few years ago and it turned out to be the throttle stop pin on my MP 60mm broke off. Once it fell off, the throttle plate would close too far with my foot off the gas and the car would not idle. It would sinply start up and die. Again, make sure your throttle plate is correctly adjusted.

im thinking i have a vaccuum leak in the intake manifold gasket...idk i read over on neons.org that a guy had a safc hooked up and it was causing the map sensore high voltage...

Since when does a vac leak do anything but make the car idle at a HIGHER RPM?

It didnt idle high. It wouldnt idle at all. But i got it fixed, i had the in and out hook ups wrong on my SAFC.