Started great before installing but acts up now

[Wesley Bennett]

97 5.7 started fine in the Tahoe now put it in 97 c1500 runs great but starting it backfires then starts just enough to kick out the starter. New fuel pump and filter. When it starts it runs great.

 

[Schurkey]

What is the fuel pressure at prime? When the engine is being cranked? When the engine is running?

How old are the usual "tune-up" items? Distributor cap, rotor, plug wires, plugs? Has the distributor offset been checked?

Connect a scan tool, verify EVERY sensor and computer output, along with fuel trims when cranking and when first started.

Is the EGR flowing exhaust gas at idle?

 

[Komet]

Timing could be off. Fuel pressure would also be good to know.

 

[Schurkey]

Timing could be off.

'97 would be Vortec. Timing is not adjustable. Distributor offset is adjustable, though.