Fuel pressure questions....

 
Old 10-03-2001, 08:51 PM
  #1  
Honda-Tech Member
Thread Starter
 
Incognito's Avatar
 
Join Date: Jul 2001
Location: Dirty Jersey, USA
Posts: 925
Likes: 0
Received 0 Likes on 0 Posts
Default Fuel pressure questions....

Somebody please help me out.

I'm working on a turbo LS/VTEC with 8.5 to 1 compression right now, running a T3/T04 custom turbo setup. The car would boost in 1st and 2nd gear, then die out in 3rd. I am running a stock '95 GSR ECU on this setup, with no knock sensor. Does that affect anything (limp mode or anything?) The only check engine light code I get is for the knock sensor. We checked the fuel pressure and it was at 80psi. Not sure if my FMU is dead or something. Not sure what brand it is, but it's silver, about the size of the unit that comes in a Drag kit, and has 2 nipples on the top, 1 has a bleeder screw thing on it. Seems like after we set the fuel pressure, it doesn't always hold, because after we rev the car, it sometimes changes. The car seems to run best with the fuel pressure around 63psi at idle. Is that wrong? With 63psi at idle and the bleeder screw all the way opened, it will boost sometimes (wastegate set at 9psi), but breaks up and pops.

Please help me out. Thanks.

By thw way, right now I am running stock '95 GSR injectors and a Walbro 255gph intake fuel pump.
Incognito is offline  
Old 10-03-2001, 10:16 PM
  #2  
Member
 
Join Date: Sep 2001
Posts: 1,071
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Fuel pressure questions.... (Incognito)

sounds like a cartech unit to me,
http://www.cartech.net/fmu2020.html

but i know nothing about tuning them
i'm in the process of gaining knowledge too!!!

HTH
Giuseppe is offline  
Old 10-04-2001, 09:47 AM
  #3  
Honda-Tech Member
Thread Starter
 
Incognito's Avatar
 
Join Date: Jul 2001
Location: Dirty Jersey, USA
Posts: 925
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Fuel pressure questions.... (Giuseppe)

My FPR or FMU thing looks somewhat like that one, but it's a little more squared, and it's rough, not polished like the one in the pic. Probably an older one. Somebody please help me out.
Incognito is offline  
Old 10-06-2001, 06:38 PM
  #4  
Honda-Tech Member
 
speedworks's Avatar
 
Join Date: Jul 2001
Location: elizabethton, tn, USA
Posts: 1,519
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Fuel pressure questions.... (Incognito)

you definetly need the knock sensor hooked up.sounds like a cartech,had a new
one and it would not work properly. switched to vortec and solved my problem
speedworks is offline  
Old 10-07-2001, 06:23 AM
  #5  
Honda-Tech Member
 
Evil DOHC's Avatar
 
Join Date: May 2000
Location: Bada BING, NJ, USA
Posts: 2,137
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Fuel pressure questions.... (speedworks)

Your FMU is definetly busted. May I suggest lowering the pressure to around 60 psi with the hose off at base pressure (at idle). Then borrow or buy another fmu. With stock injectors u might want to use a 12:1 disk on the vortech or any other brand u buy. The reason the car is poping is because it is getting flooded with fuel. U can try to take the fmu apart and see if the rubber inside either busted or something is stuck open. Personally I would buy another FMU. I guarantee that is your problem. The car won't go anywhere if fuel is just being dumped and not burned.
On a 9 psi spring u will run over 100 psi of pressure at wot. If the FMU is functioning properly. 60 at idle plus 9psix12pounds of pressure per psi of boost=108. So around 168 pounds of pressure at full throttle.
EVIL
Evil DOHC is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
personalt
Honda Civic (2006 - 2015)
5
08-23-2014 09:39 AM
Tyler Con
Honda Civic / Del Sol (1992 - 2000)
2
01-21-2008 09:55 AM
hondastrtracr
Tech / Misc
3
05-01-2006 09:12 PM
turb
Forced Induction
5
05-12-2005 11:05 AM
fastfour
Forced Induction
8
09-01-2001 03:30 PM


Thread Tools
Search this Thread
Quick Reply: Fuel pressure questions....


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: