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My 5.3 won't start and I'm stumped.
Car ran fine before
Has fuel/good pressure
Has spark
No codes
My plugs are wet with gas and my obd2 is reading my iat and my etc are both at -39° c. I'm thinking it's the ECT because there are two wires, one yellow and one gray. I couldn't find the pin for the gray one and but I found one for a brown wire but it's for the ECT so I don't know.
OH. Geez. I don't think ECT or IAT would cause it to not start, though it could cause it to run in an inappropriate area of the tune, if that makes sense?
Have you tried varying amounts of thottle to see if the behavior changes? How did you verify spark? Is this DBW or DBC?
OH. Geez. I don't think ECT or IAT would cause it to not start, though it could cause it to run in an inappropriate area of the tune, if that makes sense?
Have you tried varying amounts of thottle to see if the behavior changes? How did you verify spark? Is this DBW or DBC?
I'm currently in the process of pulling all the plugs to make sure they all have spark. And it's cable.
How certain are you that you have the IAC and TPS wired up right? I would try cranking while slowly applying throttle...start at like 2% or so and very slowly work your way up to 20% or so and see if you get any action.
Do you get a MAF reading at all? Truck setups have IAT integrated into the (5 wire?) MAF so if you created an IAT issue it is probable that you have a MAF issue, too. No MAF but expecting MAF will run like **** at best and likely require throttle to not stall.
Maybe pull your IAC of the TB and leave it plugged in but then cycle the key and turn the engine over and see if it moves in/out.
How certain are you that you have the IAC and TPS wired up right? I would try cranking while slowly applying throttle...start at like 2% or so and very slowly work your way up to 20% or so and see if you get any action.
Do you get a MAF reading at all? Truck setups have IAT integrated into the (5 wire?) MAF so if you created an IAT issue it is probable that you have a MAF issue, too. No MAF but expecting MAF will run like **** at best and likely require throttle to not stall.
Maybe pull your IAC of the TB and leave it plugged in but then cycle the key and turn the engine over and see if it moves in/out.
Well it definitely has spark. Has fuel because I clearly saw some coming out the head. I do get a MAF reading and I'll definitely try giving it throttle. But what do you mean moves in and out?
On DBC setups, the IAC(idle air control) sets the idle speed. It has a plunger on the end that moves in and out of an orifice on the throttle body to let more/less air in the throttle body to keep the engine idling. If it isn't working right(due to a wiring or other issue?) you may not get the air you need for the engine to start/run. Basically an electronic version of the idle screw on a carb. Make sense?
There's a stepper motor in there that moves that black plunger on the end in and out.
On DBC setups, the IAC(idle air control) sets the idle speed. It has a plunger on the end that moves in and out of an orifice on the throttle body to let more/less air in the throttle body to keep the engine idling. If it isn't working right(due to a wiring or other issue?) you may not get the air you need for the engine to start/run. Basically an electronic version of the idle screw on a carb. Make sense?
There's a stepper motor in there that moves that black plunger on the end in and out.
Ok so the nipple thing doesn't move when cranking but when I turn the key back to off it goes all the way out and then back in. Is that normal?
I don't think I mentioned that I think there's more fuel be shot out than there should be. It begins to smell like fuel in the garage even if I'm cranking for like 10 secs.
Ok I got something the gray wire from the coolant temp sensor was in a different pin. So I swapped it for pin 41 on the blue. Obd2 reading went from -39 to 28.
It's late now so I gotta start it in the morning
Ok so the nipple thing doesn't move when cranking but when I turn the key back to off it goes all the way out and then back in. Is that normal?
That sounds like it is wired up properly.
Do you get any popping or any noise indicating combustion? If you have that much fuel, probably a good idea to turn it over a bit with fuel pump disconnected, plugs out. Also with plugs out the engine spins faster and you get oil pressure to everything. Good for situations where you have been turning over a lot with a lot of fuel in the cylinder. Have you verified that you didn't switch the fuel injector words around? Do you possibly have the coil harnesses backwards?
How old/trustworthy is the gas? Is this returnless or return-style with a regulator?
07-01-2016, 05:45 PM
5.3 wont start 
the gray wire from the coolant temp sensor was in a different pin. So I swapped it for pin 41 on the blue. Obd2 reading went from -39 to 28.