Fuel Pressure WAY too high!!
 

Aight...heres my set up.
Stock turbo (with upgraded wastegate, bov etc.) S5 Motor, upgraded exhaust, intake, intercooler...a few other things, 4x720cc injectors, and a fuel pump from a Supra TT (just installed today...pump from FD wasn't delivering enough fuel). I also have a rechipped stock (n374) ecu with an e-manage (blue) attatched.

Right now the car is running exceptionally rich (9-10 afr) and the fuel pressure has my 100psi fuel pressure gauge pegged (i.e. fuel pressure is over 100 psi at idle)

Here's the question... Can the E-manage be adjusted to lower the massive fuel pressure coming from the upgraded pump or should I invest in an after market FPR?

Thanx!

btw... I am aware that a higher flow fuel pump shouldn't increase pressure but ...what would have?(maybe I can find the culprit and not have to get an FPR (right away)

The FPR regulates your fuel pressure. It's either malfunctioning or not seeing a vacuum.

Sweet maybe I missed a vacuum line ...I hadn't though about that...i'll check thx!!!

its best to change to an aftermarket FPR when you upgrade the pump. Not only will it let you eliminate the PD, it also lets you adjust fuel pressure to what ever you want.

Alright so I checked the vacuum. Thats all fine and dandy. I'm gonna check for a clog in the return line (though I doubt it since fuel was flowing normal with the old pump). Looks like I have no choice in the matter. I will have to get an Aftermarket FPR. Oh well it's better that way anyway (it's just a cost I was hoping to avoid for a while). Big Thanks to Macs and Ronin!!!

Your piece of shit fuel pressure gauge is BAD.
There is no way the car would idle with 100psi of fuel pressure at idle speeds.

Either you'd be getting like 3x more fuel that you need, or the fuel injectors would lock up from that kinda fuel rail pressures...

Get another gauge.



-Ted

Fuel pressure can't be electronically adjusted. With a significant pump upgrade like the Supra pump, you should be running an adjustable FPR unless you can alter mixtures electronically. You can do that with the Emanage, so you just need to have it tuned properly.

Any pump upgrade should increase fuel pressure, there's no way to avoid that. But barring a complete blockage of the return line, there's no way you should see that much pressure. An increase to 40-45psi (static) would be more realistic. Like Ted said, your gauge is probably the real problem.

electric FP gauge? if so check to see if any wires are grounded?

Aftermarket FPR fixed it!!

nope all grounds were good.

I did have to replace my fuel injector seals and the electricalplugs for my primary injectors (the enormously high pressure actually blew them apart luckily I have a few extra harnesses sitting around). I'll have to post pics when I get a chance.

Umm.... just a quick note to RETed...Autometer doesn't make "piece of shit fuel pressure gauges" that are "BAD"....and at $200 a pop they better not be.

Thanks for all your help guys!!

so heres a few pics of one of the electrical plugs (the other one was actually in worse shape but I can't find it...probably in the driveway or something. Anyway you get the point well enough from the pics.

I'd never run an Autometer gauge in my car.
I still think they are a piece of shit.


-Ted

thats too bad...I guess you don't want The Best for your rex. I only say they're the best because NHRA, ALMS, NASCAR and Motor Trend all pretty much agree on that point...Tho I bet if you get some customized for a few grand they might be better...:uhh:

Anyway, the new FPR is in place and gauge reads 40 psi at idle and I'm back in action.

Again, to those that were helpful, Thank You very much!

so what kind of gauges do you run Ted? and is there an actual explanation of why the Autometer products are "a piece of shit?

If you think Autometer are the best you're deluding yourself. Massive marketing doesn't make something the best, only the best known. My one and only Autometer experience put me off for good...

Thats not from fuel pressure being to high. Thats just old plastic connectors.
I still agree with reted,Its your fuel gauge. Man I can't beleive I agree with reted.:wallbash:
I run autometer because its cheap and here in the U.S.
Thanks Robert

How about temperature gauges that read drastically off from EMS measured values, verified both with an infared non-contact gun, and by testing the temperature of boiling water (at roughly sea level)? Testing that and finding them reading low on 3 separate gauges was enough for me.

But hey, NASCAR, NHRA, ALMS, and Motor trend all run them, so they must be the best, right? I mean, corporate sponsorship BY Autometer could have nothing to do with it, right?

After all, Ferrari, Lamborghini, Porsche, Saleen, and McLaren all sub out their gauges to Autometer for their world class supercars since they know their customers want the BEST, right?

Multimillion dollar F1 teams, the most advanced racing cars built on the planet, demand that their chassis' are equipped with Autometer gauges, because nothing beats Autometer.

And, of course, the best, and most accurate gauges, with today's sophisticated technology, are available for an amazing price of $50!

Don't buy into manufacturers' advertising.

Autometer definately makes some junk, at least some of their stuff. My oil pressure sending unit went bad.

But give them a break. Autometer boost gauges come stock in SRT-4's.:uhh:

Wow, that's news to me...
Can you show me references to where all those "organizations" explicitly claim Autometer is the best?
I would like to read up on it myself!

Personally, I normally run all Japan stuff.
But that's just me...

"Best" to me is one MoTeC ADL with lab-grade sensors.
The ADL can be programmed to any sensor characteristic you can throw at it.
If we're talking about stand-alone gauges, try looking up SpA gauges...

$200 Autometer fuel pressure gauge?
If this is the unit that uses the pressure tranducer, then I'll give you a little credit.
The sensor is already half the cost of the "gauge" itself, and it's not your typical changing resistance pressure sensor.
Although I would still not run one of these in my car...


-Ted

Do you really think that's an off-the-shelf Autometer gauge? Sounds like a nice little marketing deal to me... ;)

just to throw this in, I use GReddy Gauges and they are great.

i've driven one and a friend has one. it looks exactly look an autometer boost gauge (and behaves like one) except it says SRT where autometers usually say Autometer.

honestly, it's way better than what passes for typical boost gauges on most cars. DSM's for example are horrible (although they just estimate boost they don't actually measure it) and so are 3000GT/Stealth's