Just finished the swap

[speedyz]

1999 Camaro 3.8
5-Speed
Flowmaster catback
Well my 3.8 blew at 110K, cause unknown. I keep up regular maintenance and the motor has only seen mobil oil ever 3k. I don't romp on it much since its a camaro with a grand am engine :P. Driving home from work a few weeks ago and got a nasty knock. Babied it home but it was too late. Got a new motor from a firebird for 300$ with 77k on it. Did a mild rebuild with new bearings. My question is this- on the first start the motor cranked over and over, for a good 2 minutes (time not exagerated) and then all of the sudden BOOM it fired right up. The problem does not pertain, now the motor fires almost instantly. Just seemed strange, even older builds such as carbed motors on their first start only took ~30 seconds. Anyone know what the reasoning behind this is? I am also getting terrible gas mileage. Highway trip I got about 16, in town I am getting around 14. My old 3.8 consistently got about 20 in town.

[UDLOSE98]

Re: Just finished the swap

your compression could be ****ed
poor fuel pressure

[slow6]

Re: Just finished the swap

Did a mild rebuild with new bearings. My question is this- on the first start the motor cranked over and over, for a good 2 minutes (time not exagerated) and then all of the sudden BOOM it fired right up. The problem does not pertain, now the motor fires almost instantly. Just seemed strange, even older builds such as carbed motors on their first start only took ~30 seconds. Anyone know what the reasoning behind this is? I am also getting terrible gas mileage. Highway trip I got about 16, in town I am getting around 14. My old 3.8 consistently got about 20 in town.

You should've put new rings in it. If you took the rods/pistons out then you might have low compresion.
DO NOT continuously crank an engine for 2 minutes straight... hope you didnt.
Hope you gave your starter a little break.
30 seconds is alot of time.. even on the first start ever.
Also your ECM/PCM probably has to relearn the fuel trims (if the battery was disconnected for longer than 30 mins at a time).
Eventually the mileage will get better
GL

edit: maybe after say 50 miles.. let the rpms get up kinda high.. might help file/seat the rings

[speedyz]

Re: Just finished the swap

You should've put new rings in it. If you took the rods/pistons out then you might have low compresion.
DO NOT continuously crank an engine for 2 minutes straight... hope you didnt.
Hope you gave your starter a little break.
30 seconds is alot of time.. even on the first start ever.
Also your ECM/PCM probably has to relearn the fuel trims (if the battery was disconnected for longer than 30 mins at a time).
Eventually the mileage will get better
GL

edit: maybe after say 50 miles.. let the rpms get up kinda high.. might help file/seat the rings

Sorry about the clarification. The motor did receive new rings. The continous cranking was about 15 seconds going, a few seconds off, 15 seconds going, a few seconds off, then after I let off for a few seconds, I turned the key and it barely cranked over and fired right up. Starts up just fine now. Cranks a few times in the cold. Motor is running fine, got about 300 miles on her. Still dealing with the fuel problem though.