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

Hi,
Right up from I am very much a noob on anything but brakes, some suspension stuff, and oil changes on newer cars. My son has a 2008 MS3 that has a Gen 2 motor in ti (First one blew @ 190K miles.). The motor was put about 6000 miles ago. No mods other than a CAI. Other than a couple oil changes and a valve cover gasket change two weeks ago we have not done anything to the car recently.

The issue happened while he was rolling down a short fairly steep grade just engine braking. When he stepped on the gas the car stalled. It would not start at all. We towed it home and it sat for a couple days until yesterday. We tried staritng it and it fired and stumbled, but would not run. I have a cheap code reader and we are getting a P0193 (high pressure circut input) . From what I read, it can be a fuel pump, a fuel rail pressure sensor, or...??? The wires and connecrtors to the sensor all look good. When we pull the in-feed line to the HPFP and turn it over we get a lot of gas. Can we check the pressure at this point with just a fuel pressure gauge? From what I've read the stock HPFP's rarely go bad. Can we check the HPFP pressure without an AP?

I am looking for trouble shooting steps. Can anyone help me out? Many thanks!

 

Gen 2 motors are very picky when it comes to any flow mods. Given that you have no hpfp, no tuning device, and a code for fuel I would pull the pump and check to see if the spill valve on the pump took a shit and or you have issues with the hpfp fuel pump piston. If you had a Access Port (tuner) you could monitor the fuel pressure, but without it you are pretty much guessing. I'm also guessing if we solve your problem we won't ever see you again. Good luck.

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You can get a Bluetooth obd2 plug and get torque app on your phone. That will let you monitor stuff like fp ect...

 

lol

 

Pistons never seize, ever.

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Check the ground wire (little tiny black wire) on the coil harness.

Also inspect your High pressure fuel sensor (left side of the fuel rail). @Maisonvi got the same code from smashing his sensor w/ his JMF manifold.
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Meh a stock diameter sized intake will do basically nothing on a non-tuned car. I ran (and tons of people) run a stock sized maf intake without a tune no problems. Just a little wonky trims. I wouldn't worry about one flow mod even on a PU.

I think the problem lies in either your suggestion of the HPFP spill valve, the piston or either the ground wire on the harness or the fuel pressure sensor itself on the rail.

 

I had my car die on the road just a couple days ago, fuel pressure with key on but engine off was over 1700 psi. I removed the fuel pump, clean the relief valve and all is well now.

 

Thanks for all the suggestions. I do post if I have something worthwhile to help someone (I've posted several tome on the Mazda 6 forum and the Honda Odyssey form (I am an old man compared to most on this forum) and compared you all of you I am way out of my league. I commit to posting the solution if/when I find it. I am headed out to check the sensor voltages now.

I would have replied sooner, but I spent 14 hours of my day at my friggin job. Again Thank you!
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Also,
read through the thread about the mashed connector. I pulled mine & it looks OK, but I am headed out to check the voltages. I will also inspect the ground wire. We had a couple ground issues right after the motor swap. I am amazes how many ground points are on newer cars and every one is an PITA in waiting.
[doublepost=1491303744][/doublepost]OK, Getting 5 V on the sensor wiring. I will tackle the fuel pump tonight.. If that is not the problem I will probably tow it to a garage. I'm already getting over my head...

 

You realize there's a difference between a stock HPFP failure and it simply not being able to flow enough, right?

OP, having said this, you should definitely upgrade your HPFP internals ASAP. Not that your stock ones will go bad, but that they're insufficient.

 

These cars will run on in-tank fuel pressure no problem. It is not a HPFP issue. I would try to crank the car and monitor fuel pressure and see what reading the sensor is even giving you.

 

OK, my understanding is that the MS3 has an in-tank high flow pump. WE pulled the line and I can confirm that we get a lot flow from initially when the key is turned on (and the pump energizes) & when cranking over the motor. It feeds a cam drive HPFP that apparently everyone upgrades internally....correct? We have not, and the car is basically stock. We did not have any knows fuel issues until the car died and threw the P0193 code. It turns over, stumbles but won't run. Tonight I plan to pull the HPFP, find a tutorial on disassembly and see something seems seized or broken. If the stock pump has been sufficient to date and we are not building the car I don't see the benefit in spending money on upgrading internals. Obviously if something looks worn or I will need to revisit the internal upgrade option. Thanks!
[doublepost=1491328574][/doublepost]Sorry Mongoose, I did not see your reply. We don't have an AP so I took someones suggestion and ordered a bluetooth OBDII reader that is supposed to include fuel pressure data with the correct app on my phone. Do you recommend I pull, disassemble & clean the HPFP just to be sure? Thanks!

 

I've noticed a trend in you and I being able to endlessly argue semantics, lol.

To me, for all intents and purposes, the hpfp internals not keeping up with demand is a failure in the sense of being a weak point in the system that will result in ZZB of you're careless . Technically they are still working and we're simply demanding more than what they have the capacity to deliver, yes; but in layman's terms and for purposes of more easily getting the point across to new Speed owners, I feel comfortable enough describing it as a point of "failure."

Anyway; OP, even if you don't plan to mod the car much or at all, upgraded internals are good insurance for the price to help avoid venting your block. Just something to consider.

 

Not wanting to derail beyond this, but designing the HPFP internals to keep up with stock fueling demands but not modded car fueling demands isn't a failure, it's an engineering choice. Actually, I think we're very fortunate that in many other ways Mazda engineers saw fit to design a vehicle that could push the power levels that it does on stock engine internals, easily ~140whp/130wtq over stock's 230/250 @ the wheels.

 

Definitely in agreement that they did us a lot of favors in certain design aspects. As much as we as a community rag on the HPFP needing to be beefed up, at least we don't really seem to have any common major issues at stock levels, like some other platforms do...Subies and their head gaskets, for example.

 

No point in doing anything until you have the actual pressure reading from the ECU as far as I'm concerned.

 

Thanks. Bottom line is that the car has 200K miles in it. He really likes it, but is still in college, so spending more on it than needed to keep it running well and fun is not an option right now. I have a blutooth reader on order, but may have access to a better OBDII reader that will give me fuel pressure readings before it arrives. At the risk of asking yet another dumb question, Just turning it over should give be the fuel pressure info I need to know if the HPFP is the issue...right?

 

Yep, ITFP is in the 60s, so if you see that at idle, that means something is up with the HPFP. When the HPFP is working properly, warmed-up idle fuel pressure will be in the 410-430 or so range.

 

Thanks Redline...As of two days ago it would not start, so unless I accidentally did something to improve that condition I can't get FP readings at idle. I think I read somewhere that someone had a 2100# reading with just the key on & it was a bad sensor. Assuming I don't spike a high number will I get a pressure reading >60-70 PSI if the HPFP is functioning just cranking the motor over?

 

Sorry, man, I know idling and WOT pressure levels that're normal, but not cranking pressure levels. Maybe someone else in here does?

 

Yeah, you'll get somewhere in the 60-125 range I believe just cranking over (been a while since I did that though, might spike higher). If the sensor is pegged at 2100+ for sure it or the wiring is bad. In tank fuel pressure should be around 40 psi. Idle should be about 425 psi with the HPFP working correctly.