Chasing a P0190 code

[Sully008]

Hello all,

Late last fall I started getting the P0190 code popping up. It would be accompanied by P0000 and a third code (lately it’s been P0020). The second and third codes I’m not too worried about as they have been random. But the P0190 has me concerned a little.

Jump to this spring and I’ve started to troubleshoot the problem. I’ve read threads on here that the P0190 isn’t really an issue, just clear it and go but in the 10 years the car has been S/C’d I’ve never had this code come up until now.

Some background on the car:

82,500kms on it. Stock engine, stock trans w/3000 stall converter, JLT intake, Kooks headers, Trilogy w/3.2” pulley on it. MAFia on stock MAF. 39lb injectors, stock fuel pump, stock FPDM, Kenne Belle Boost a Pump set to 20 (haven’t verified, it’s been a while since I’ve checked). Hobbs switch is bypassed. FRPS is boost sensitive. Car was dyno tuned to 443hp, 401tq in 2010, haven’t been on the rollers since, and I haven’t done any upgrades power wise.

Note I don’t have an A/F gauge currently. Something I will be addressing.

I can get the code to show up when I’m cruising along at ~50kph (30mph) and then go WOT. The car will downshift and haul @#$, but the check engine light will come on. No stumbles, no drop in power. I am monitoring fuel pressure via a Scangauge II, and when I do this I notice that pressure drops from ~40psi down to ~15-20, then rises up from there. Right now I’m assuming that the stock fuel pump is on it’s way out.

I did some maintenance recently (change oil, plugs, clean MAF, IAC, trans fluid, FRPS, fuel filter). Still need to change rear diff oil, but that has no bearing on this issue. I thought that changing the fuel filter and FRPS would solve the problem, but it still remains.

My next steps would be to verify that the BAP is still working, which should be an easy check. Is there a way of checking the FPDM? I assume if there’s power there, then it works.

I’d like to datalog the fuel pump and fuel system in general, as I have access to an SCT X4 and Livelink. What PIDs should I be monitoring besides voltage, duty cycle and pressure?

I’ve refrained from going WOT for now until I get this figured out. I’ve had a Ford GT fuel pump sitting on the shelf for a few years now. Maybe it’s time to install it.

Am I on the right track thinking the pump is going bad? It is still the original one that came with the car. Anyone have any thoughts or comments?

[blazen71]

https://www.mercurymarauder.net/forums/showthread.php?t=49174

[Sully008]

https://www.mercurymarauder.net/forums/showthread.php?t=49174

Hi blazen71,

That was one of the threads that I read where the parameters of the FRPS should be changed. But my concern is this has only started to appear last fall? If this was the issue from the beginning, shouldn't I have gotten this code sooner? Any thoughts on the pressure drop on the initial WOT hit? Since I have the Ford GT pump, I might as well install it anyways. It's doing no good sitting on the shelf...

If that's all I need to do, then I'll have to find a tuner that can do it for me, since the local one that did mine has gone AWOL.

[fastblackmerc]

Hi blazen71,

That was one of the threads that I read where the parameters of the FRPS should be changed. But my concern is this has only started to appear last fall? If this was the issue from the beginning, shouldn't I have gotten this code sooner? Any thoughts on the pressure drop on the initial WOT hit? Since I have the Ford GT pump, I might as well install it anyways. It's doing no good sitting on the shelf...

If that's all I need to do, then I'll have to find a tuner that can do it for me, since the local one that did mine has gone AWOL.

All electronic components degrade over time. That's probably why you haven't gotten it sooner.

[Sully008]

All electronic components degrade over time. That's probably why you haven't gotten it sooner.

True, but are we talking about the FRPS, or the pump? I've changed the sensor and still get the code. I'm still leaning towards changing the pump anyways. It's now 16 years old. If I still get the code, I'll have to get the parameters changed.

[blazen71]

Replace the pump with the GT pump and ditch the Boost a pump. I cannot answer if you would need tuning or not.

[Sully008]

Replace the pump with the GT pump and ditch the Boost a pump. I cannot answer if you would need tuning or not.

Ya, that's what I'm leaning towards now. May keep the BAP, but we'll see.

[musclemerc]

1- get an A/F gauge your sc’ed you need one

2- do a full wiring upgrade to the fpdm and install a 40amp relay
Tap the white wire on the inertia switch to trigger on/off

3-install the GT pump and yes leave the BAP in place

4- wiring should be at least a #8awg and should route as follows
From the battery to a 40amp in line fuse (no more than a foot away), route to the trunk to the 40amp relay, relay out into the BAP, out the BAP to the fpdm (make this connection no more than an inch away from the fpdm.

Hopefully by then the problem is fixed. I didn’t get how many psi your making but IF your making at or more than 13psi you need to swap to a dual fpdm/pump setup.

[Sully008]

1- get an A/F gauge your sc’ed you need one

2- do a full wiring upgrade to the fpdm and install a 40amp relay
Tap the white wire on the inertia switch to trigger on/off

3-install the GT pump and yes leave the BAP in place

4- wiring should be at least a #8awg and should route as follows
From the battery to a 40amp in line fuse (no more than a foot away), route to the trunk to the 40amp relay, relay out into the BAP, out the BAP to the fpdm (make this connection no more than an inch away from the fpdm.

Hopefully by then the problem is fixed. I didn’t get how many psi your making but IF your making at or more than 13psi you need to swap to a dual fpdm/pump setup.


Thanks for this. I do need to get an A/F gauge. FYI, on the 3.2" pulley I'm at 10psi although I'm thinking of going smaller (either 3.0 or 2.8).

[musclemerc]

^^^^IF you can find one.....http://www.southfloridapulleyhq.com/

Keep in mind the Trilogy is a Magnuson SC, those pulleys are getting hard to find.

There was a company in Florida making them http://www.southfloridapulleyhq.com/

FYI 3.0 will put you @13.5psi (I ran one on my old setup)

[Sully008]

I have both.�� But I'll worry about swapping the pump first, ventilating the block second, lol. I do have a teksid block for building in the far, far future.

[Marauderman]

Well this P190 code has been around awhile from all the references --and rightfully so...…………...I have replaced the sensor 3 time myself--not sure why it seems to eat that thing, may be like some have said ..the tuner needs adjusting for it to read a difference ----anyway --I had to replace it once again last Friday--- --and it was not the issue I was chasing to begin with-- I was getting a P-174 code for months--but a check of my initial text to those in the know Friday actually revealed the true cause--it occurred from when I cleaned my MAF last.--I hadn't wipe it clean and it remained with too much cleanser spray because I didn't wiped it off and thus collected stuff on it as it was sticky and kept sending that code--which was not the real problem--because once I realized this and cleaned it the motor has been running great and no codes!!

However, while trying to ID this culprit , I went further and installed both front O2 sensors----Well after I did clean the MAF after the O2 sensors were installed I swear the car runs like it has an additional 50 HP and really strong and goes after that extra push without hardly trying--a real WOW factor-

So not sure if your fuel pressure sensor is your problem but I have learned/realized that when changing the O2 sensors it did cause the P190 code to come on and a new pressure sensor solved the problem and with power --I guess when changing O2 sensors a change of that fuel sensor may just do the same for anthers--not sure --after all how many times do you change or need to change O 2 sensors? Don't know but that is what happen to me.

Really enjoying much more power thru all the gears way much more and sooner than ever before!!

May be that has helped --not sure-

[Sully008]

Interesting thought. As with alot of things on this car, the O2 sensors are original. I might have to think about changing those too.

[musclemerc]

Just wondering!!

I've never replaced my FRPS sensor. Been boosted for years, still on the original unit.

When ya"ll did the install did you set the FRPS up so it sees boost and vacuum? or did you hook it up to just vacuum?

[Sully008]

Just wondering!!

I've never replaced my FRPS sensor. Been boosted for years, still on the original unit.

When ya"ll did the install did you set the FRPS up so it sees boost and vacuum? or did you hook it up to just vacuum?



Mine is set up to see both.

Edit: The car was also dyno'd with it that way.

[Marauderman]

Interesting thought. As with alot of things on this car, the O2 sensors are original. I might have to think about changing those too.

Yeah---as far as I can remember mine were original too---either way the newer ones with the newer fuel pressure sensor seem to just open that beauty up!!

[Sully008]

Yeah---as far as I can remember mine were original too---either way the newer ones with the newer fuel pressure sensor seem to just open that beauty up!!


Just checked rock auto and the Bosch sensors are only $35cdn each. Might as well do them, they're relatively inexpensive.

[Marauderman]

Just checked rock auto and the Bosch sensors are only $35cdn each. Might as well do them, they're relatively inexpensive.

Sounds like a good move---lets us know what the after effect is---

[Gerry24]

I’m chasing the infamous P1131 code. Looking to swap out all 02 sensors soon. That :censor: CEL...