Removed engine, re-fitted and now starts poorly and dies.

[214jay]

Having some problems with my 89 Firebird 350TPI. I have recently re-fitted the engine which has been out of the car for 1.5yrs (ish). Everything has been connected and the engine turns over with (sounds like it is struggling half of the time), it will eventually fire up but die immediately. If I slightly press the accelerator pedal the engine will run quite nicely and stay revving (over 1000-12000 rmp) but as soon as I release the throttle it dies again instantly. I have fitted new dizzy, rotor and leads which I believe are in the right order.

The engine service light is on but reading no fault codes (just flashed code 12 constantly). I do not have an exhaust on at the moment, only hedman hedders with the exhaust sensor modified into the lower end - Not sure if this relates to the problem?

Smog/Aircon has been deleted, otherwise standard.

Has anyone any ideas? I can post any videos or photos if needed.

Thanks!

[SUPERCHARGEDGTA]

if light is on then could be poor connection or something not connected/plugged in

[214jay]

Unfortunately situation has worstened. Although it still fires up and sounds nice occasionally it is impossible to turn over by hand even with spark plugs out. Stumped

[jonbullnose]

strange! what was the reasons for removing the engine in the first place? what have you done to it and why? this may help us track down any issues thanks jon