fuel psi at idle, please help

PWRD_BY_HKS · Post by **PWRD_BY_HKS** » November 26th, 2007, 12:14 am

Okay guys I'm having this problem with my car. Honestly I don't remember having it before the afpr!

It runs great no problems on or off boost but once I come to a stop the car begins to like drop rpms down to like 400 ....... Just low. I have checked all my vaccum lines and found nothing. Actually the car reads 19-20 psi of vac at idle.

Let me explain, it doesn't do this all the time. Only once in a while. No pattern, so its not like it will only do it if I hit boost, or something like that. It just does it some times.

I decided I'm taking off the manifold sometime this week to see if maybe I missed something. Before I do so I wanted to know what you all have your afpr set to, I was told by a friend I might be flooding out since I'm at 40 psi at idle. Remember though, the car runs great untill you make a stop. And that it only some times.

Btw. I was messing around with timing also. By turning the Disty towards the hatch side of the car it actually helped a little. But still the problem is there and it is obvious.

I have a 4 lbs waste gate yet I can't seen to hit 4 lbs. I get to 3. Like I said I checked for leaks. Please help me. Am I flooding my engine with too much gas!?

This time I really need the help guys thanx.

Limegreen mx-3 · Post by **Limegreen mx-3** » November 26th, 2007, 12:19 am

check ur plugs what are u running with

hgallegos915 · Post by **hgallegos915** » November 26th, 2007, 1:15 am

I have 15 psi at idle.. before everyone stops yelling at me.. no im not running lean.. its at 12 when cold and 14 when warn then it goes to 12.

When i had my psi at 40 my cat would flood out at idle.

I have millenia s injectors.

could be you have a faulty fuel pressure regulator..

are you sure its flooding? what are you using to measure the af?

The tps will cause it to die too if not adj properly in combo with the air idle screw.

PWRD_BY_HKS · Post by **PWRD_BY_HKS** » November 26th, 2007, 9:57 am

Are far as plugs. I am running densos but I haven't had time to pull them out.

I don't know if I'm flooding I think I might be but I honestly don't know. I don't think its a vaccumm issue because it doesn't loop all crazy like vaccumm losses do. It just kinds feels like all of a sudden it just dies.

hgallegos915 · Post by **hgallegos915** » November 26th, 2007, 2:05 pm

well its not the plugs as im running the stock ones with a smaller gap.

I dunno what else it could be, only way i was able to solve this is by moving the tps a bit higher and adj the tps screw. Mine was runnign fine and at stops. boom.. it would shut off.. or it would beidling fine and then for no reason it would turn off like if someone shut it off.. weird o.0

PWRD_BY_HKS · Post by **PWRD_BY_HKS** » November 26th, 2007, 11:21 pm

hmmmmm..... you see the thing is i know most people run like at 30... but since i dont have wide band, its kindaf scary...what if i blow it....

PWRD_BY_HKS · Post by **PWRD_BY_HKS** » November 26th, 2007, 11:42 pm

okay i know andy is running a smiliar set up to mine and sets his to 30 psi.... but he has a 8:1 fmu.... mine is 12:1 ..... does that make a difference.... or not......

andy · Post by **andy** » November 27th, 2007, 7:28 am

not so similar, I have a 1.8 L you have 2.5L. I'm still running the stock 1.8L ECU. My ECU thinks its working with 180cc inj not the 220cc inj I have installed.
I don't think this is a timing issue.
Your FMU would should have no effect on your idle.
Do you have the coolant still running through the TB?
3 vs 4 psi, I would not put so much stock on the accuracy of the boost gauge.
I would suggest going thru the procedure to set the idle.
I would adjust the AFPR, I mean thats why it there to be adjusted.
Just go slowly, a little at a time.

Andy P. 93 GS 1.8T

hgallegos915 · Post by **hgallegos915** » November 28th, 2007, 1:07 am

whats the stock injectors psi at idle?

rudy invest in a wideband, guessing sucks.

MazdaManiacMx3 · Post by **MazdaManiacMx3** » November 28th, 2007, 11:25 pm

Is the problem happening when you boost and quickly come to a stop ? Could be a BOV problem ?

Idle ruff at all or any CEL codes ? Could be a Coolant temp sensor(completely non turbo related)

BTW to test this go out and boost the car and come to a quick stop , Look at the RPMs and see if they fluctuate after the clutch is pushed in , If they do its a possible sticky BOV (not uncommon with cheapies)
Kris -

PWRD_BY_HKS · Post by **PWRD_BY_HKS** » November 29th, 2007, 2:14 am

thanks bro, i think i fixed the problem... i clocked the disty as far back as i could and opened up the idle control screw and so far no problems....

now my question with AFPR is.....

i just needed to kick up pressure just a tad more than stock.... so does anyone know the flow of the stock FPR ..... that would be imesly helpful!

MazdaManiacMx3 · Post by **MazdaManiacMx3** » November 29th, 2007, 9:54 am

Pm'ed you back , feel free to post the PM , if you find it to be helpful to other people ,
Thanks
Kris

PWRD_BY_HKS · Post by **PWRD_BY_HKS** » November 29th, 2007, 2:58 pm

Thanks for the help Kris. This is the replied PM

Subject:Re: heySo do you have a RRFPR = Rising Rate Fuel pressure regulator ? If so do you also have a adjustable FPR = Fuel Pressure regulator just for idle ? I dont think that you need both , So I would ditch the adjustable FPR for idle if you have one and trade it for the stock, besides thats what the rrfpr/FMU is really designed to do for every pound of boost it compensates the change in Air fuel ratio to a set amount of fuel monitored through vacuum pressue. I assume that you are not running a wideband ? In these circumstances this is where a wideband really comes in handy , I suggest you pick one of these up and monitor your ratio , that way you will be able to work out all the little problems you are having right now , You can pick up a AEM UEGO for around $200.00 on ebay nowadays , and its one of the best on the market, Also for more tunability consider picking up a Megasquirt Standalone system to optomize the power you are making , and ensure reliability , as your current RRFPR is not adjustable. For a cheaper method of tuning consider a "Bell engineering BEGI" Adjustable RRFPR with a small adjustment knob on it , As for the BOV problem , Its not so much a Gas then brake thing as much as a Gas get on the boost and instant clutch action will provoke this with a sticky BOV , used to do it on my WRX RA but then I swapped out the BOV for the stock recirculatory valve to correct it. I hate BOV's they are really more problems then they are work , they release all the air tricking the car to thinking it has more air than it actually does , causing the car to run very rich therefore "flooding the engine" , I run Recirulatory valves AKA: Diverter Valves on my turbo'ed vehicles for this reason. Please let me know if the following helped you. feel free to post this on the forums if you think it will help other people, Thanks and good luck , Kris__________

Just one thing I'm a bit confused on. Rrfpr=fmu correct?

MazdaManiacMx3 · Post by **MazdaManiacMx3** » November 29th, 2007, 3:46 pm

Yeah , I actually even put that in the mix where I went rrfpr/fmu, I tried to incorporate everything the best as possible , so there would be minimum confusion ,
So you are running both a "FMU" for boost and a adjustable FPR for idle?

Kris-

MazdaManiacMx3 · Post by **MazdaManiacMx3** » November 29th, 2007, 3:48 pm

Get a Wide band 02 no matter what, and if you don't feel comfortable going MegaSquirt or Standalone for that matter ,
The Begi found here is your best bet for "FMU's"
http://www.racetep.com/begireg.html

Kris-