Gen 1 stumbles on hot start

[david.ott141]

My 2014 Gen 1 with 123k just started to stumble on hot starts when you immediately select start after inserting the key. Engine stumbles, sub idles, then runs fine. If I insert key, select on for 5 secs, then start, the motors fires exactly as it should.

Originally thought fuel pump, then read a post identifying a faulty crankshaft position sensor as the culprit. I think I would rather replace the pump rather than the sensor. Any votes/ideas? Otter

 

[Nex]

Welcome to FRF and please post pictures of said hard starting prius.

Have you used forescan to check for codes? What is your fuel pressure on key on?

 

[david.ott141]

No check engine light, but others have said likewise. Have not scanned yet. Will get that done next week after I return from a trip. Thx, Nex!

 

[EricM]

There is a check valve (PPRV) on alot of Ford fuel systems that prevents the fuel from flowing back into the tank. It's in the tank, right after the pump(s). Not sure if the Raptors have that as I've never been in the tank- be it might be your issue if it does and it's stuck open.

 

[david.ott141]

Thank you, Sir!

 

[cturnbo]

I’m having the same symptoms on on a 2011 with 154k. Did you have any luck getting this fixed?

 

[pat247]

It could be the canister purge valve. This fixed a weak/slow start issue my Raptor was having.

 

[david.ott141]

I’m having the same symptoms on on a 2011 with 154k. Did you have any luck getting this fixed?

See the post directly below. Believe the culprit is a return valve either on the rail or as mentioned earlier, in the tank. I’ll figure it out after it cools off a bit. In the meantime, I delay from the on position to the start position about 5” by muttering “atomic battery to power, turbine to speed” and it fires without issue. That only will make sense to you if you grew up watching Batman and Robin in the 60s.

 

[srvtraptor]

See the post directly below. Believe the culprit is a return valve either on the rail or as mentioned earlier, in the tank. I’ll figure it out after it cools off a bit. In the meantime, I delay from the on position to the start position about 5” by muttering “atomic battery to power, turbine to speed” and it fires without issue. That only will make sense to you if you grew up watching Batman and Robin in the 60s.

Interesting -- just ran into a similar problem myself a week or so ago. 2014 Raptor with 156K on the clock, going to check this next! Already did fuse 27, fuel pump relay module, made sure MAF was clean and ran Forscan (0 codes)