Jj94k1500

I have a 94 k1500, 188,875 miles, I rebuilt the 5.7 tbi in it, bored .30 over, flattop piston, 447 roller cam and lifters , 98 vortec heads, long tube headers, no cats, tbi chip with specs of engine, egr delete, when cold it will start right up, once good and warm I have to floor it to start back up, acts to be overloaded or flooded. Then runs good again. Rebuilt the fpr. What could be my problem? Has new temp sensors, oil pressure switch, everything else is new except the injectors. I'm attaching my cam card as well.

93G20

I have a very similar setup minus a chip (next on the list)
My truck will do this too, every time it's the starter. Do you have a heat shield on it?

Jj94k1500

Mine spins normal but I have to put the gas to the floor or it won't crank then slowly let off to make it run every time it's warm. I have no heat shields.

93G20

The headers put out a lot more heat and once the starter is hot it has trouble turning the motor. When you open the throttle the injectors cut off and air flows easier which makes it crank. The only other thing I could think would be vapor lock. Check the vent hose to the tank for clogs. Add a heat shield and see if it helps. When you times the motor did you unplug the esc wire?

Jj94k1500

Yes I unplugged the wire. All new lines, filter, and sending unit.

93G20

If your starter spins freely and doesn't act like a dead battery then I think you have an issue elsewhere. I did have an issue with the wiring on the front coolant sensor and it caused all kinds of issues with starting hot and running, but only sometimes. Very irritating to find. Maybe try some jiggling of the harness while it's running or when trying to start it hot with no gas pedal. That's how I found it, would about die when I moved the harness a certain way.

Jj94k1500

All my gauges work fine, doesn't run hot, just after running I have to floor the gas to get it started, then runs good again, just hard to crank warm issue like she is overloaded or flooded.

93G20

The temp sensor I'm speaking of is by the water neck. It doesn't go to the gauge, just the ecm.

When you say crank, do you mean the engine is slowly spinning with the starter or do you mean it spins fine but won't fire? Hard to crank means a slow spinning starter and engine to me. Just making sure I'm not misunderstanding you.

Fixed my hard start when hot last night. Loose ground connection at the battery. My truck started fine when cold but only wot when hot like the battery was weak. The only other thing I could think of is your injectors are leaking. Take off the cleaner and prime the pump a few times with the key but don't start it. See if they are dripping gas.

Jj94k1500

Spins normal, no weak battery or dragging starter, but acts like no fuel until I floor it and have to let off slowly then it will run fine. Acts flooded or overloaded. Rev a lil bit and runs normal again.