Help - Slow crank & stalling

[tators50]

I recently swapped my engine. 5.7 vortec, I got it running drove it home nothing weird next morning It started drove about a quarter of a mile and shut off like I turned the key off. Battery shows full charge wen hooked to a charger but now it struggles to crank and if I can get it to catch I have to keep constantly feathering the throttle to stay running soon as I let off it stalls.. I can't figure it out any advice?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

The first step is to confirm that you have a good battery. Fully charge it with your charger, and then remove the battery and take it to an autoparts shop with a bench battery load tester. IMO, this is the only way that you can fully test a battery.

If your battery is good, then check the heavy gauge cables going from your battery to the starter, the power fuse block, to the alternator, and to the ground on the firewall. Perform a resistance test on each of them, as they tend to rot from the inside out, while still look good from the outside.

If these are all good, then I'd pull the starter and check it out.

 

[exp500]

A fuel pressure tester is a very useful thing on these trucks. A 6 foot hose helps too, tuck under wiper and can monitor pressure while underway.

 

[Eman85]

Check both ends of both battery cables after being sure battery is fully charged. Then if it starts check voltage at battery to be sure the alternator is charging.