I will info dump first to get any helping hands up to speed. In the last couple months I have had a tone of issues related to random misfires dealing with plugged cats. So in that time I have put a new mad,map, 4- o2 sensors, pulled cats out. New plugs wires, cam and crank position sensors, and fuel pressure regulator. The other day on the way to family’s house on Xmas it died on me. Had to get a tow. Just died while doing 50, threw it in neutral and coasted to a safe spot. It cranks and has fuel pressure and spark. It will not start. What should I do?
CK5
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Need some help 5.3 no start
- Thread starter mark84k5
- Start date
Any codes? What is the fuel pressure?
Fuel pressure is a little over 50psi
Don’t have scanner
That would be my first thing.
yeah either of the new sensors cam or crank could be the culprit. What brand are the new sensors ? sloppy terminals the connectors can loose continuity
Did you do a crank position sensor relearn when you replaced it?
What codes does it have?
Start checking and cleaning all engine harness grounds.
What codes does it have?
Start checking and cleaning all engine harness grounds.
I know some may think why am I using used sensors but I have 3- 5.3 that ran when pulled sitting around and I have been shotgunning parts to get it running. Not ideal but is in the teens (temperature) here and I’m just trying to get it running!
oem sensors should be fine, some aftermarket can give dirty signals. I would be looking at connections, Pulling codes will help narrow down the system.
Did check pending codes?
The reader I bough said I had no codes . So non active or pending!
check engine light will be on when engine is not on.
Correct, but when you do the scan it says to have the key in the acc position. Also I can’t get the truck started if I wanted.
Key should be in the on position, but not running.
I think you need the crank sensor for spark and fuel, but cam sensor only affects fuel timing, like it should start with a bad cam sensor. I don't have proof of this, so some one can correct me. If it's sparking, you probably have a crank signal. For fuel, a stethoscope on an injector should tell you what it's doing.
To test your code reader, you could unplug a sensor to see if the code shows up. You should be able to run with a bad MAP sensor, as it's usually secondary, but a MAF that's wrong can screw everything up. Another free test is to leave either the MAF or the MAP unplugged and see if it's any different.
To test your code reader, you could unplug a sensor to see if the code shows up. You should be able to run with a bad MAP sensor, as it's usually secondary, but a MAF that's wrong can screw everything up. Another free test is to leave either the MAF or the MAP unplugged and see if it's any different.
Nice that it's so warm there. Happy New Years and fix it next year!
