91 305 tbi stock,,,just got engine back in and i set base timing to 3 degrees..turned car off,, hooked the est wire back ,,cranked car and it runs long enough to idle up and run two seconds and dies,,,,,it does it every time i try to crank it ,,unhook the est wire and it will idle all night,,,,did some research prior to asking but is it bc im not disconnecting the battery after i hook the est wire back up,,,or is it something else,,???

 

Are you advancing 3 degrees for performance. Stock is 0 degrees.

 

I remember hearing the 305 tbi likes being 3* advanced, im pretty sure mine is as well and after setting mine and hooking the wire up i didnt have this problem. Just to be safe though i would set it back to 0* and see what it does. Also maybe try disconnecting the battery and turn the key on to drain the ecm and see if that changes anything. I remember the first time i messed with my timing it was idleing like it was cammed, then i found the vacuum line i knocked off the back of the tbi.

 

, it doesnt matter what degree i give or take from base timing ,,,did unhook the battery after setting base timing this morning and still getting the same result,, cranks and runs 2 seconds and dies,, unhook est wire from distributor and runs just fine,,,all vacum lines are new and in correct place,,,and doesnt runn long enough to throw a code ,

 

Was anything done with the distributor while the engine was out? Was the IAC connected?

Can you keep the engine running by pedaling it?

Fuel pressure OK?

RBob.

 

All sensors are hooked up n functioning nothing done to distributor, fuel pressure is good and it will run if i peddle it but it wants to die,, still

 

Since the only difference between having the EST/BYPASS open or closed is the spark advance, I'd start there. Open the BYPASS and check hte timing with a light. Slowly rev the engine and check that there is a sudden advance around 1600 - 1800 RPM.

Then with the BYPASS closed check the timing again. Make sure that it advances from the base timing. At idle it should be around 18* BTDC.

RBob.

 

Could the ecm be getting a signal, like knock counts, that would cause it to start advancing timing so far that it dies? Would make sense why it only happens with est wire connected right?

 

Swapped out distributor witch had a new icm and set base timing and ran well,, so im guessing icm had gone bad during everything being taken out and put back in,, havent made sure its bad but will find out ,,thanks for all opinions