Stalling then ok 10 min later

2003 Tahoe LS 5.3 Flex, 218,000 miles

I live in FL – hot

Engine stalls but runs fine 10 min later for a few miles but no issues during the morning commute. I can leave in the AM and tow a boat for an hour with no issue. On our way later in the afternoon it starts acting up 15 minutes into our ride. I can feel it start to hesitate on acceleration then it stalls out. 10-15 min later it starts, and we run fine for 3-5 miles. I replaced the MAP and throttle body. On the same day I was able to tow the boat for an hour with no issue. A few days later if I floored it doing 60ish rpm’s would go up but the speed didn’t increase. A week has passed since replacing the above parts and it stalled on my way home last night. The only code it’s given me was P0300 last night. Fuel pressure is 50psi. The catalytic convert temp is about the same for the in/out sides. Thoughts? Defective throttle body? Clogged cats? ECM issue?

Thanks

did it set the p0300? or it flash show as pending?

might be as simple as your way over due for a tune up. plugs and wires.

or maybe the crank sensor, when bad they dont always set a code. if the tack ever dropped to zero before it stalls out, crank sensor for sure. but thats what it does, stall out when ever it feels like it, then fire back up 15 minutes or longer of sitting.

T2003 said:

A few days later if I floored it doing 60ish rpm’s would go up but the speed didn’t increase.

Click to expand...

That particular symptom sounds like a transmission issue. Not sure about the stalling, though.

Just following up as I hate threads that never have the final outcome/fix. It completely died the other night. It would just turn over and not start. Did all my testing and this time there was no fuel pressure. I replaced the fuel pump and for 2 days now she has run great!! Time will tell if this was the cause of all my issues.

T2003 said:

Just following up as I hate threads that never have the final outcome/fix. It completely died the other night. It would just turn over and not start. Did all my testing and this time there was no fuel pressure. I replaced the fuel pump and for 2 days now she has run great!! Time will tell if this was the cause of all my issues.

Click to expand...

My guess wouldve been Fuel Filter then Fuel Pump. 50psi seems to be right on the edge of min.

rockola1971 said:

My guess wouldve been Fuel Filter then Fuel Pump. 50psi seems to be right on the edge of min.

Click to expand...

Fuel pressure values depends on when and how it was measured. If doing the standard KOEO test, yes, 50 would be low. Lots of folks, though, just measure it running, so there's a different minimum for that way. The OP didn't state the technique.