P0193 , Stalled, & won't start out of the bLue?

I checked the wiring and got 5V between the signal and reference and 0V between the signal and ground, which I understand confirms I don't have a wiring issue. I am basing this on the youTube video I watched (below). If what I found is accurate and I peg at 2100+ it must be the sensor. I have a friend who thinks he can get ma a scanner that reads fuel pressure. If he can't, I bought one of the blue tooth OBDII readers that states it reads fuel pressures (Thanks 5doorsoffury!).

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Still troubleshooting...I bought at BT code reader and managed to get a fuel rail pressure reading. Unfortunately it took us a while and we had cranked it over several times figured out how to display the fuel rail pressure. It read around 1650 and did increase to over 1700 when we turned the car over. It tries to run but won't. Even a small push on the gas pedal seems to make the car stop firing. It almost acts like it is flooded. Am I way off my rocker or can I be getting too much fuel? I accidentally cleared the P0193 code and it has not come back through our attempts to start the car. I was actually hoping for a pegged pressure, even if it meant a new fuel rail. It feels like one step forward, two back...
 
That's unusual. At idle and upon startup, fuel pressure at the rail should be somewhere around 450psi. More pressure doesn't equal more fuel necessarily; it's just at a higher pressure.

On the frame rail, below the intake, there's a ballast bolted to the inside of the rail. I'm not sure what role it plays with our fuel system, but I know that if it's unplugged, pressure will be extremely low (around 50, the in-tank fuel pump pressure), and the car won't start. I suppose that could mean that if it's somehow shorted, the opposite could possibly happen.

Also, inspect the wiring harness near the cold air intake. Make sure the clamps haven't worn through the insulation.
 
A little better info...The KOEO is 1650's, but goes up bit when we tried to start the car again, then drops after a couple cranks to as low as 1375. While the engine is turning over and stumbling it hovers in the 1500 range until we stop turning it over, then it goes pretty quickly to around 1655. It almost runs, but wont. We get flow out of the INFP line that feeds the HPFP, but can't seem to get a pressure reading on our scanner. It may be we don't have the reader configured correctly. Gonna keep digging, but if these number mean something significant to anyone please weigh in. Thanks.
 
I found a friend of a friend who has garage quality scanner. He scanned the car both KOEO and while cranking it. The fuel rail pressure starts at 1650+ without cranking the motor over. It changed but stayed in the 1500-1700 range until we stopped turning it over. With the key left on it settled to 1650 again. His scanner said the "target pressure" is 1015 PSI ( I assume when starting). He thinks the pressure sensor is reading but sine it is so high when trying to start the computer might be shutting off the spark. I've read several threads about the relief valve failing to hold pressure. Is it possible that mine is stick closed? If not, can the sensor just be toast where it cant "find" zero, but can still detect pressure changes? Thanks.
 
Just a thought, but you may want to investigate the spill valve on the top of the HPFP itself. That's another point of failure that's known to get clogged up sometimes. A good cleaning often fixes spill valve issues, but a new HPFP may be in order (unfortunately, you cannot get the spill valve by itself). It's the electical connector assembly on top of the HPFP (the harness plugs into it) that unscrews with a very large wrench, I think like 3/4" or so.
 
Thanks. After reading several posts on the spill valve I planned to clean it since it is probably waaaay overdue, especially since may owners seem to clean it as a a routine PM item.
 
I've been traveling & working a lot, but found some time to tinker a bit more. With the HPFP hose disconnected the FP srill reads about 1615-1625. If I unplug the sensor it spikes to 2281 (same as Maisonvi's reading when he broke his sensor connection) so the sensor is reading. It almost seems lie the sensor has lost it's "zero". With the fuel line connected and KOEO the reading was ~50# higher which is what the in tank FP would add. I am really thinking it is the sensor. Thoughts, comments, gaffaws?
 

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For sure there is a problem with the sensor or wiring. I would make sure the wiring is OK first before replacing the sensor. Do you have a copy of the FSM?
 
Actually I don't. I assume you recommend it for troubleshooting the wiring. I can buy a CD version, but I can't download it. My internet might as well be dial up. I did the simple volt meter test a while ago and got the 5V on the plug between the signal & reference and zero volts between signal & ground. I thought that proved the wiring was OK.
 
Calvin said:
Actually I don't. I assume you recommend it for troubleshooting the wiring. I can buy a CD version, but I can't download it. My internet might as well be dial up. I did the simple volt meter test a while ago and got the 5V on the plug between the signal & reference and zero volts between signal & ground. I thought that proved the wiring was OK.
Click to expand...
The fsm is available here as a donated member. You'll have to download it though.

crapatalk it sucks for free
 
PROBLEM SOLVED!!!!!!:b2::b2::banana2::banana2::aaaaa::aaaaa:

For anyone interested...

The problem started when the car stalled just driving through town. It would not start & we towed it home. It would fire but not run.
-A cheap code reader threw a P0193 code; Fuel sensor voltage out of range
-Confirmed good fuel flow from in tank pump and sensor harness voltages
-Checked fuel rail pressure and found 1650 PSI with KOEO
-We unplugged the sensor and the pressure read 2281 PSI
-Bought sensor for $70 (matched Bosch numbers on the sensor and bought it overseas) and installed it.
-VIOLA!!! Started right up and runs great!

While I will probably get hammered for installing a sensor rather than buying a fuel rail, I want to point out that the fuel line is attached to the rail with a cheap plastic clip vs. a threaded steel base on the sensor. The fuel line connector seems much more likely to fail than the threads on the sensor.

Finally, I want to thank everyone for the suggestions offered throughout this challenge. I learned a lot about fuel systems and troubleshooting.
 
Calvin said:
While I will probably get hammered for installing a sensor rather than buying a fuel rail, I want to point out that the fuel line is attached to the rail with a cheap plastic clip vs. a threaded steel base on the sensor. The fuel line connector seems much more likely to fail than the threads on the sensor.
Click to expand...

Awesome dude, I'm really glad this is fixed. Yeah, I know Mazda recommends replacing the rail with the fuel pressure sensor as a unit, but I've never understood why that is. Good to know it can be done. Can you list the Bosch part number for the rail sensor for others?
 
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