i recently swapped an lt1 into my buddies car i just finished everything and went to fire it off well it ran for about 2 seconds so i tried it again and gave it some gas it ran again so i held it at about 2500 and itll run all day long but as soon as i try to idle it down it shuts off. i quit with it that night. i tried it the next morning and it did the same thing itll run for 2 seconds and now i cant even get it to run at 2500. the security is not on so its not that its got fuel it just dies out any help would be greatly appreciated thanks

 

thanks for all the help

 

Sarcasm will get you no where, either on this forum or in life

You need to forward a bit more information before a possible remedy can be established

 

well don't give up on one day of noone answering. The information that you have provided, although is all that you know of the situation, is quite vague. Is there any trouble codes, have you checked the fuel pressure, obviously if you got it to run for a while the first day at 2500 rpms it's got spark, i'm leaning towards PCM tuning depending on any modifications you did along with the install, or fuel. Have you replaced the simple things like fuel filter, make sure all the lines are good, chekc fuel pressure? Possibly a tune up if the engine wasn't originally yours and you don't know the condition it was run at before you acquired it. Start small and work yourself up.

 

Maladjusted Minimum Air or IAC?

 

1) As stated, check fuel pressure. Also make sure fuel pressure doesn't drop immediately after shutting off the car - that would be a sign of leaky/bad injectors, leak in the line, or possibly bad fuel pump.
2) If you have a mass air flow sensor: http://shbox.com/1/maf.jpg, you can disconnect it, and then start the car. This will run the car in a less fuel efficient mode called speed density mode. If the car runs a ton better then its probably that sensor or the rubber elbow could have hole/leak in it.
3) http://shbox.com/1/map.jpg - Could be a bad MAP sensor. Also the tab of the wire connector is know to break off(dried out plastic) and cause a bad electrical connection which results in bad readings from the sensor. Wrap a zip-tie around the connector and map sensor temporarily to keep the connector in place or replace the electrical connector if broken. Car will not run good or at all if something is wrong with the MAP.
4) Check spark plugs and spark plug wires. NGK TR-55's are good and inexpensive spark plugs for the LT1.
5)Check all electrical connectors. Check for any chewed up wires. Check all vacuum hoses. Make sure the right fuel injectors all plugged in to the correct electrical connector for that injector.
6) Could be a bad ignition coil
6) Could be bad temperature sensors but kind of doubt it. http://shbox.com/1/4th_gen_tech2.html#ect
8) Optispark

Start with the simple stuff first - plugs, fuel pressure, electrical connectors before you start replacing big things like the optispark.