First of all the c&l meters are garbage. Second the FP gauge you have is for a carb setup. You need one for a fuel injected car. And 3rd your not going to be able to tune the car with the FPR. You need to get a real tune which will control the AFR through the computer. AFR should be between 12-13.7 or so to 1

 

how are c&l meters garbage?

 

any adjustment done on the fpr will be tuned out by the computer within 3 to 5 drive cycles, until you go so fat or lean that the computer cant pull or add any injector cycle. At which point it will trip a fault and put the car in limp mode.

 

Idk i like the meter its worked good so far and cleaned up my idle and my WOT alot. And i figured thats what my AFR's should be at there pretty close now just didnt know for sure on the 5.0's im more familiar with the modular platforms. I would rather just try it myself by tunning my fuel pressure than overpaying for a sct chip and a 400 dollar tune when i can get it close enough with the stuff i have now. Thanks for your help though i feel stupid for buying that carb FPG now i guess i just wasnt thinking lol.

 

So basically i just bought this pricey AFPR for no reason and its completely worthless?

 

If you can't tune at all with a Afpr why have one?? Everyone says to get one to tune???

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I am running a pricey regulator too. Everyone doesn't say get one to tune. Many of the experienced tuners helping me, tell me the stock one is fine. Consistency is what you want when you are trying to dial in a tune. Adjusting fuel pressure is not a tune. In my brief tuning experience, an AFR is a patch you can use to cheat and make your injectors act different than their rated capacity. You don't need that with a real tune if your components are approximately right. A real tune adjusts things at different rpms and all the other variables. A raise or drop in FP is there all the time.

 

You can't tune a computer controlled engine with a FPR. And most tuners will ask you to either take off the aftermarket FPR or just set the fuel pressure to stock on a setup like yours. So yeah it's pretty much useless

 

R.etheridge
how are c&l meters garbage?

Most people don't clock them correctly or run them too close to the t/b they then blame the meter. Also a FPR only makes global changes across the rpm band. They are essential for any build especially people who live in areas that experience weather change. Which is everywhere no doubt your FP requirements will change from a 90* day to a low 50* day.

 

So now we are varying fuel pressure based on ambient temp? :blam: Care to point out this temperature based fuel pressure adjusting sensor? Certainly not what goes on in our EFI cars.

 

liljoe07
So now we are varying fuel pressure based on ambient temp? Care to point out this temperature based fuel pressure adjusting sensor? Certainly not what goes on in our EFI cars.

If by sensor you mean a thermometer then yes lol.

liftedford17
Now this I have to hear. Care to explain? This is too funny...can't wait to hear this about tuning for changes in temp. Especially through a FPR lol

90* air low density 50* air higher density a common used ratio is 1% increase in HP per 10* drop in air temp. So a 350HP combo in 90* FL would theoretically make 364HP in 50* NY. Not a huge jump by any means but enough to rich or lean out a combo. It would be foolish to assume they would have the same air fuel ratio. Oh but then again how is it that you change your air fuel? I'm not calculating for altitude so be kind.

 

If by sensor you mean a thermometer then yes lol.



90* air low density 50* air higher density a common used ratio is 1% increase in HP per 10* drop in air temp. So a 350HP combo in 90* FL would theoretically make 364HP in 50* NY. Not a huge jump by any means but enough to rich or lean out a combo. It would be foolish to assume they would have the same air fuel ratio. Oh but then again how is it that you change your air fuel? I'm not calculating for altitude so be kind.

Its called a ECM! Never heard of a Mass Air Sensor? ACT sensor? BP sensor?

How about Fuel Multipliers? And no, it doesn't multiply the fuel pressure. :shakehead
And there is more. Suggest you read the strategy so you don't make any more retarded post like that in the future.
:lol:

 

Farrit - the ecu does all those pressure/temp related calculations for you and makes the appropriate changes. Thought everyone knew that.... I think you must be thinking of an ancient modestly controlled fuel leaker called a CARB.

If your stock regulator is holding pressure at 38-39 psig without the vacuum line connected (engine at idle) then there is absolutely no benefit to putting an adjustable in. The piece of equipment to start with is actually a FP GAUGE. If the stocker's not doing it's job - then get an adjustable and set it to the STOCK specs. The ECU/MAF/O2 sensors do the rest.

 

Your computer and tune takes care of the AFR as the temp changes. It's all in the tune. Has nothing to do with a FPR

 

Word

 

I guess I should just throw away my adjustable FPR and put a stock one on there. Clearly every combo is the same and requires the same fuel pressure how foolish of me. But I could have sworn the last time I was on the dyno my motor made max power at 42psi. But clearly this must be a spoof because obviously that's too much pressure for those injectors lol. You can run what you want and expect your ECU to make up the differance across the board. But like I said a FP adjustment makes global changes across the board. What does the mass air do for you at WOT?

 

I guess I should just throw away my adjustable FPR and put a stock one on there. Clearly every combo is the same and requires the same fuel pressure how foolish of me.......

If you truly tune your car, the excerpt from your post is a true statement.

 

Another post on corral
Trip to the dyno

--------------------------------------------------------------------------------

So i decided to strap the fox to the dyno to find out how its running before doing any more racing. The car has a systemax 2 top end kit, BBK LTs,O/R X, Mac mufflers and although I was hoping for 300 or more I couldnt help but realize that this would be best case scenario. The pull is made and as I look at the screen and notice 263/295....Disappointed! But as I look closer I noticed a torque curve that resembled a sine wave, yes up and down the entire pull. I noticed the car as leaning out, not seriously bad at first but really bad as RPMs increased, over 15:1 at one point. As I look at the power curve I realize the pull was stopped at 5k rpm due to the A/F ratios but the power not only flatlined but dropped after 4700 rpms, the point where AFRs go over 15:1 (you can get a view of the AFRs at the end of the vid before he lets off, it's the bar that moves left to right below the speedo and tach on the computer). Timing is set the 14* base and no adjustment was made to the fuel pressure because it as found to be at 46lbs. A Diablo chip has been ordered. :icon_headbang: anyone think I can pass the 300whp mark??

I guess if he just dropped his FP back down to stock he wouldn't need a tune and he'd deff hit 300hp. If he'd only read this thread sooner lol.

 

He did drop it back down. Did you not read the thread? More fail from the weasel.....

Are you really asking what the Mass Air does at WOT? More proof you need to stay away from EFI. I guess you also don't know that small fuel pressure adjustments will cause the ECM to pull fuel? Fuel tables are set in the ECM, its always going to try match that. Tons of tuners will tell you the stock regulator works just fine, provided the injectors are sized right and a few other variables.

Please enlighten us with more of your stellar EFI tuning tips......

 

Wow. The rodent gets dumber and dumber with each post. Can't wait for him to drop more useful knowledge on us lol

 

Rodent/weasel lol.....clearly been called worse by better. If you read the post I quoted it's awesome to show differances of opinion. I've found through my experiences and combos through the years an AFPR is essential. You obviously don't agree so good day to you sir........

 

You are incorrect with what you are saying about a FPR on a computer controlled fuel injected car. You couldn't be more wrong

 

What was the original question?LOL....Might as well spend the very reasonable amount of money on a Moates quarterhorse and BE/EA (binary editor/EEC Analyzer) and open up a whole new can of worms...

 

What if you don't tune your car, the Afpr can help get things close can't it? I mean if the computer is commanding X pulse width due to the tune, and the injector is too large or too small to deliver the correct amount of fuel needed for the O2's to send the correct AFR to the computer, wouldn't an Afpr going higher or lower bring it in?? The computer doesn't know what pressure your at, only final AFR at the O2?? Right?

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If I remember correctly, the ECM can add or subtract up to 12% of fuel. You would have to raise the fuel beyond the ECMs ability to control fuel. Generally, if the ecm is adding more or less than that 12%, there is an under lying issue.

Most use the afpr as a bandaid fix because the injectors are to large or small. That's why its not needed with correctly matched parts. Like farrit said, it makes global changes. Which is junk for tuning. Let's say you wanna richen up the top end by raising the fuel pressure, since its a global change, now you have a overly rich idle, and cruise. And once you get outside of that 12%, the ecm is going to log lean or rich codes.

I have an afpr on my junk, but its at stock spec. I believe I got it in a trade, and just used it for looks.

 

Increasing the line pressure makes the injector behave like a larger injector, yes.May have to search (OP) for semi-successful results using this approach.Driveability may not be too good,then again who knows til you try?

 

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Pretty much...

He could always disconnect the 02s, clear the KAM, and go from there. But all that nonsense just so you can play with fuel pressure and still get sub par results? Its the equivalent to clubbing your mate in the head, and dragging her back to your cave. LoL

 

LOL, exactly why I decided to make the investment and begin learning to tune.

 

QuarterHorse?

 

So i figured i would give everyone a update, Got my car tuned over the weekend and my tuner hooked up my AFPR and set it to 39psi and ran it and then went all the way to 42psi. once he got to 43 the car started loosing power and he dialed it back down to 42psi. he told me that this is where the motor and combination wants to be at FP wise and is the best place to start tuning. He also told me its not necessary to do this but it might add a few hp and give me piece of mind knowing my motor is always at the FP it likes to be. Does this make sense to you guys? Would release dyno sheets but want to do a few more things to it before i do ;] Also just to have alittle fun what do u guys think it pulled? lol

 

Find another "tuner". Your motor is not "always at the FP it wants" now. As already stated by Michael, your motor compensated for the FP adustment on the way home. He should have verifed your FP was correct and put the guage away. These are 1987 methods used in hopes of making a stock injector act like it is a little bigger. Guy helping me learn to tune with my new Quarterhorse had a fit when he found out I had an adjustable FP regulator. I understand why now.

 

I'd be interested in finding out how much it drops your AFR if you lower your FPR say 1 PSI. I'm pig right right now and would like get it a LITTLE closer before I hit the dyno.

IE, 2 PSI roughly lowers your AFR 2 points. Or something along those lines.

 

Yesterday I put a 255lph high volume pump in to replace the stock pump I had been using along with my Vortech t-rex. I also installed 36lb injectors with a calibrated maf. On initial startup in open loop the car ran great with a 14.x:1 on my wideband. As soon as it went into closed loop, the a/f dropped to the low 11's and the car would eventually shut off while searching for the right mixture which it could't achieve. My fuel pressure was 41-42 with the vac connected which indicated that the stock fpr was being overpowered by the two pumps.
I cut power to my t-rex, the pressure dropped to 35 vac on and the ecu was finally able to lean it out to about stoic on it's own. Car idles great, big injectors and all.
I plan on getting a Moates from dirtydirty racing soon so it will be good until then.

So to answer your question, if its a bit rich and you lower fuel pressure you may be able to help the ecu lower a/f to a ratio that will allow you to move around a bit until you get a tune or tuning device. :salute:

 

"I'd be interested in finding out how much it drops your AFR if you lower your FPR say 1 PSI."

Here we go again. In closed loop the ECM is designed to CONTROL AFR's to whatever is in the table. If you lower the fuel pressure, the ECM will simply KEEP THE INJECTOR OPEN LONGER in order to keep the AFR the same. You may see a change for 1 or 2 or 3 wide open throttle pulls on the dyno. But by the time he's driven home - the ECU will adjust for the higher pressure by shortening the pulse-width....

The second he started playing with fuel pressure I'd have found another 'tuner'....

Edit -- sorry, open slipped in when I clearly meant closed....deslixia....

 

"I'd be interested in finding out how much it drops your AFR if you lower your FPR say 1 PSI."

Here we go again. In open loop the ECM is designed to CONTROL AFR's to whatever is in the table. If you lower the fuel pressure, the ECM will simply KEEP THE INJECTOR OPEN LONGER in order to keep the AFR the same. You may see a change for 1 or 2 or 3 wide open throttle pulls on the dyno. But by the time he's driven home - the ECU will adjust for the higher pressure by shortening the pulse-width....

The second he started playing with fuel pressure I'd have found another 'tuner'....

No, in CLOSED LOOP the car makes adjustments to the fueling by way of the O2 sensor feedback. Stored adjustments are then transferred to the OPEN LOOP static values that are programmed into the ECM.

The only time it is prudent to use an AFPR to jack up fuel pressure, is if you need to bandaid your car/tune... Because your injectors are too small. If you don't adjust the injectors hi/lo slopes in the tune afterwards, the computer will readjustment and turn your tune to crap.

Fuel pressure should be set at 39psi w/no vac reference... Period!