Hi Guys Im New To Form Need Help With My 88 3.0 V6.the Prob When I Start It Miss And If U Try To Give Any Gas It Backfires Through Throttle Body For Bout 5 Sec And Them Runs Fine. When It Cools Down And Sits Afew Hours It Does The Same Thing When Starting. Hope Someone Has Heard Of This.this Is A New Motor Has Bout 15000 Miles On It And Has Done This Since Day 1 And The Old Motor Did The Same

 

Do you have the same muffler and cat from the last engine? Have you replaced the o2 sensor?

 

Yea I Replaced O2 Bout 6 Mts Ago The Muffler Has Also Bn Changed And I Have No Cat On The Truck.the Od Thing Is That I Have No Error Codes Check Engine Light Dose Not Come On. It Acts Like To Me It Gettin To Much Gass Because At The End Of Pipe It Is Black Like Its Running To Rich. Thanks Guys For Help I Need This Fixed.