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| Forum name | Turbo/Nitrous Tech |
| Topic subject | lean under boost |
| Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=524 |
524, lean under boost Posted by Dave16gt, Dec-29-00 07:51 AM
Hi, Ive got the HRC kit and I still cant get the fuel pressure quite right. Its fine when im not under boost, but if I floor it it begins to studder and my a/f guage drops to lean. If I gradually get into boost it does not studder but its not reaching full boost, the 8psi for the stage two kit. Also the brass adjustment knob on the fuel regulator is turned almost all the way in, for the highest fuel pressure. So why is it running lean ? Has anyone else had this problem and know what to do? Thanks.
Dave16gt
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525, RE: lean under boost Posted by DarkOne, Dec-29-00 08:25 AM
I'm having the same problem with my STAR kit. Only, my EGT reads low temps when i'm under boost, but it still stumbles when i get on the throttle, just like you described. When you figure out the problem, let me know or if i get it first, i'll let you know. What gauges do you have ?
-DarkOne I'm so bad, i should be in detention.

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526, RE: lean under boost Posted by JasonESi_T, Dec-29-00 08:34 AM
Dave, are you ascertaining this lean condition by looking at the a/f meter by itself? What does you fuel pressure guage say? I really don't think you hould have that brass screw turned all the way in to achieve the fuel pressur eyou want to be at? Do you have your EGT guage in? Is it hot?
I guess what I'm saying is that the a/f meter is probably the last device in terms of reliability in determing if your car is lean or not.
Probably, your first device to rely on is the fueal pressure guage. At 9 psi, you need 105-100lbs of fuel.
Jason 98' Eagle Talon ESi-T Mitsu Super 16g Turbo(HRC)

http://springfielddsm.homestead.com/JasonsPics.html
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527, RE: lean under boost Posted by Dave16gt, Dec-29-00 09:15 AM
I dont have a EGT guage on my car. The fuel pressure guage hahn gave me kept leaking into the the guage to the point the I could not read it. I installed an auto meter fuel pressure guage today, I put it on the same -T- that the hahn fuel pressure guage used, off the FPR. Although it will not regester any fuel pressure when the car is on nor when I drive it. It just stays at zero. Thats why I was using my a/f guage.
Dave16gt
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528, RE: lean under boost Posted by JasonESi_T, Dec-29-00 04:35 PM
Well, then I doubt that you're lean considering where your brass screw is turned to. Try and get tghat fuel guage working or call HRC to get one that works. The a/f meter merely a omplimentary piece not meant for heavy diagnosis of any condition. The EGT is also valuable.
Jason 98' Eagle Talon ESi-T Mitsu Super 16g Turbo(HRC)

http://springfielddsm.homestead.com/JasonsPics.html
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529, RE: lean under boost Posted by BLKOUT, Dec-30-00 02:38 AM
Do you have the base fuel press. set right? Jason is right about the A/F not being very good for diagnosing things. My A/F reads lean when I'm under boost alot, but I know my fuel press. is right. Do you have any ideas why the new fuel press. gauge is not working? Keep us posted. Later.
Joe 97 GS w/ Hahn stage 2 Keep cruisin' & keep the shiny side up. http://joeseclipse.homestead.com

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530, RE: lean under boost Posted by Dave16gt, Dec-30-00 05:20 AM
Yeah Ive got the base fuel pressure set right. At idle its about 52 psi. I set htis while my fuel pressure guage from hahn was working and i haven't changed it. Last night I turned the brass nob out to 1 and 1/4 turns and now it seems to work fine. My a/f reads lean under boost but the cars drives well with this setting, but you said this happens to you also. As for the auto meter fuel pressure guage I have no idea why it would not work, its simple to install. Thats what im going to do today, maybe ill just get a different guage and see if that one works.
Dave16gt
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531, RE: lean under boost Posted by Shant, Dec-31-00 02:29 AM
Where are you gonna get one from that reads over 100psi? Let me know when you do, thanks
Shant 98 Turbo Avenger
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532, RE: lean under boost Posted by BLKOUT, Dec-31-00 04:55 AM
NOS makes a fuel press. gauge that reads over 100psi. You can get it from NOPI.
Joe 97 GS w/ Hahn stage 2 Keep cruisin' & keep the shiny side up. http://joeseclipse.homestead.com

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533, change your fuel filters guys Posted by Tommyboy, Dec-31-00 05:04 AM
maybe you guys never changed your fuel filters before the install of your turbo kits that could be the problem it happened to my friend's honda ( )
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534, RE: change your fuel filters guys Posted by Dave16gt, Jan-03-01 12:37 PM
Okay I got another fuel pressure guage, this one works kinda. My base fuel pressure seems so increase each time I turn the car on. I know it sounds dumb but each time I turn the car on the base fuel pressure has increased slightly. Also when under boost the car only reaches about 6 psi. The fuel pressure guage stays at about 55 psi, my base pressure. Ive moved the brass nob but the pressure will not rise, or fall when I get into boost. Right now the car seems to run well with the nob turned about 2 times out. Could this just be the guage again? Im kinda stumped on this, so any ideas would be appreciated.
Dave16gt
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535, RE: change your fuel filters guys Posted by 95ESi, Jan-03-01 06:49 PM
Where do we change the fuel filters?
ANyhow, where did you hook up your fuel pressure guage?
l e o n
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536, RE: change your fuel filters guys Posted by Dave16gt, Jan-04-01 03:24 AM
I hooked it up right below the fuel pressure regualtor from Hahn. This is where they said to install it. Like when I drive and dont floor it, its okay, but at WOT the engine seems to hesitate until I let off the gas a little. The base fuel pressure stopped moving though.
Dave16gt
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537, RE: change your fuel filters guys Posted by 95ESi, Jan-04-01 04:28 AM
You may have a broken FPR?
l e o n
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538, RE: change your fuel filters guys Posted by Dave16gt, Jan-04-01 08:36 AM
Any idea how I could check that? The base pressure is fine it just does not increase when Im reach boost.
Dave16gt
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539, RE: change your fuel filters guys Posted by 95ESi, Jan-04-01 05:06 PM
Well you can initiate a fuel pump pressure test with a scan tool and then measure your fuel pressure at the service port. Then use some regulated compressed air and feed it into the FPR. You should see the fuel pressure rise. If not, check for leaks...
l e o n
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