2017 Viper hard start

[74Nitro]

So on the one I'm working on I tried a new OEM starter, cranks over good, but still will not start when cold. If I spray carb clean in the intake (MPI turbo kit on it), it'll fire off and once it's warm, will start again every time, but when cold will not start. I have checked cam timing, valve clearances, reluctor wheel phasing, unplugged GEMS box, tried another ECU (older flash), fresh pump gas, fuel pressure, spark plugs, swapped crank signal pickup, and checked TPS settings through diagnostics on dash. My next step is to take the throttle bodies completely off and see if I can swap sensor(s) (IAC or MAP) and see if that fixes anything or just start the damn thing on fire and wait to call 911?

Yes, you've eliminated almost everything.
What about the little filters in the end of the injectors?

 

[Srxspec]

Yes, you've eliminated almost everything.
What about the little filters in the end of the injectors?

So I ended up swapping around map sensors on the fuel rail with a spare set that I had laying here, with the new sensors installed it fired up on the first click of the key!!! Now the confusing thing, I put the old ones back on and it will fire up on the first click of the key with the old ones too, kinda strange!! Only thing I can think of is one of the map sensors was out of range after the starter failure (kick back & HUGE backfire according to the customer) and once I changed the map sensor, it reset something in the ECU and now will work with either new or old map sensors?

 

[74Nitro]

So I ended up swapping around map sensors on the fuel rail with a spare set that I had laying here, with the new sensors installed it fired up on the first click of the key!!! Now the confusing thing, I put the old ones back on and it will fire up on the first click of the key with the old ones too, kinda strange!! Only thing I can think of is one of the map sensors was out of range after the starter failure (kick back & HUGE backfire according to the customer) and once I changed the map sensor, it reset something in the ECU and now will work with either new or old map sensors?

Possibly, I can't answer that with certainty.

 

[Srxspec]

So this morning I tried going back to the aftermarket starter and suddenly I have a no start condition. It's not the starter though, something, somewhere is causing the injectors not to fire. I have eliminated the GEMS unit and about everything I can think of. Just about ready to give up.....

 

[74Nitro]

See post #35 in this thread -

7000 misfire at idle

I have an extra complete throttle body setup with injectors, harness, all sensors. runs the same

ty4stroke.com

 

[Srxspec]

I tore into the throttle body wire harness, but couldn't pin point a problem area or get it to start. I installed a new set of throttle bodies and it starts fine now (knock on wood).