Results 1 to 13 of 13

Thread: Tried FPM - Now my bike won't run

  1. #1
    apriliaforum Member StreetCred's Avatar
    Join Date
    Jun 2006
    Location
    Wisconsin
    Posts
    182

    Tried FPM - Now my bike won't run

    Hey all,

    So, I needed to replace a front coil and while I was under the hood I thought I would do the Fuel Pressure Mod. Got the coil in without any issue. Then I started on the FPM. Right off the bat I was in trouble. The yellow colored hoses were crumbling whenever I touched one. I don't have any idea where some of these hoses went. I thought I had everything back together. The bike would start and idle ok but would stall out whenever I would give it some throttle. At first I was thinking I just had some air in the gas lines so I got it rev'ed up and was able to drive it down the block. That was until I came to stop sign. Same thing - hit the gas, kill the motor.

    I've been looking over the plumbing diagrams but can't figure out what's messed up. I gave up on the FPM and went back to what I thought was the stock setup. The bike ran fine before I started this little project so it's something I did.

    Any help would be appreciated.
    StreetCred

    2003 Silver, wiring mod, fuel line mod, de-restricted airbox, HoMade exhaust.

  2. #2
    apriliaforum expert RAS's Avatar
    Join Date
    Aug 2003
    Location
    PA USA
    Posts
    8,396
    can't tell you off the top of my head where all the houses that should see barometric pressure are hooked together, but you should have one hose to each throttle body bottom on the left side and those should be plugged or you will have vacuum leaks that will mess things up properly.

    The ECU will have a hose that should see ambient pressure - never hook that up to engine vacuum. It's there to compensate for altitude changes. The air box drains on the right side as well as the fuel pressure regulator will also see ambient pressure. Iirc, those hoses meet up with T connectors.

    There's another hose that comes off the rear TB that goes down to the clutch - it's not likely you've messed with it.

  3. #3
    apriliaforum expert Motech's Avatar
    Join Date
    Aug 2006
    Location
    Santa Cruz, CA
    Posts
    3,157
    You've probably got your barometric sensor hose hooked to vacuum. Jusrvtrace the hose comes out the ECM and disconnect the other end. If bike runs better, there it is.

    Do some searching around. There's a good draft of vacuum hoses floating around here in several places that will make it easier to restore order. When you do, go ahead with the FPR mod. It plays real well your model year.
    No Matter Where You Are, There You Go!

  4. #4
    apriliaforum prov-nov
    Join Date
    May 2019
    Location
    Moscow, Russia
    Posts
    63
    Motech, how the FPR mod depends on tne model year?
    English is not my native language, so please be kind to my mistakes.

    Remember, this is an Italian bike with an Austrian motor, it isn't like the GSXR you use to own...

  5. #5
    apriliaforum expert RAS's Avatar
    Join Date
    Aug 2003
    Location
    PA USA
    Posts
    8,396
    Quote Originally Posted by iamdude View Post
    Motech, how the FPR mod depends on tne model year?
    Nope. There might be some differences based on the 3 maps, but unless you have a 2001 model that's still running its OE map, there really wasn't that much difference between the next 2 maps.

    This pressure regulator "mod" is a band aide, imo. For those bikes that get crappy fuel mileage, it'll help lean things out some to improve that, but it would be better to modify the map. Thesystem was designed to run w/o after all.

    If, like my 2002 Fut still running the 02 map, yours gets good gas mileage ( routinely 45-52mpg) doing that mod will likely make the thing run worse.

  6. #6
    apriliaforum prov-nov
    Join Date
    May 2019
    Location
    Moscow, Russia
    Posts
    63
    Thanks for clarification!
    Lean fuel mixture is a bad thing.
    English is not my native language, so please be kind to my mistakes.

    Remember, this is an Italian bike with an Austrian motor, it isn't like the GSXR you use to own...

  7. #7
    apriliaforum expert Motech's Avatar
    Join Date
    Aug 2006
    Location
    Santa Cruz, CA
    Posts
    3,157
    Quote Originally Posted by iamdude View Post
    Motech, how the FPR mod depends on tne model year?
    As RAS said, the mod does not work well with 2001 model factory map. In fact, it is terrible.

    It is a significant improvement on 2002 and 2003 factory maps, and worthy with the final 05 map.

    It does lean the fueling, but not where it could be harmful. It trims about 8 psi of pressure at closed throttle idling and deceleration, and steady, light load cruising. Any open throttle acceleration provides full pressure, so there is no lean fueling at all under loads, where it matters.

    I have performed this mod professionally on four Futuras, with all three available factory maps. I've recorded before and after tailpipe emissions results each time, including changes between maps. It is an excellent mod that we shouldn't need to do as it should have come that way from the factory. All RSV models and Falco did, as does every other EFI bike built. The "band-aid" was no vacuum to FPR, some suspect to compensate for the awful fueling on the first model year in their rush to bring this bike to market. We are curing the original disease with updated map, then removing the bandaid to set it up the way it should have been when sold new.
    No Matter Where You Are, There You Go!

  8. #8
    apriliaforum expert deefred's Avatar
    Join Date
    Sep 2004
    Location
    Sweden, Linköping
    Posts
    5,670
    Motech, you still think you know better than both Aprilia and Triumph.
    For some bikes the FPR mod seems to work well. Its worth a try especially if you dont have tuneecu to reduce the IFT.
    2001 RST Futura in stream Silver.
    Mods: Modified Öhlins fork from mille R, EBC 320mm brake discs, HEL front brakelines, Carbon RS 250 front fender, Wiring mod for charging. Engine related:05 map, Iridium plugs, tuneboy, derestriced intake, old mille airboot, staintunes exhaust. Lambda bung hardbrazed in the "breadbox". Öhlins mille R rear shock with 110N/mm spring and the integrated hydraulic preload adjuster. LED Voltmeter installed inside the dash for monitoring charging. Duc 999 radial m/c for brake and clutch.
    NWS hugger. Equipment: Famsa tankbag,
    CBR 600 -07 MOSFET R&R FH008EE providing stable 14.4 - 14.5 V (with my wiring mod). Daytona heated grips with mccoi pwm controller and automatic chain oiler

  9. #9
    apriliaforum expert RAS's Avatar
    Join Date
    Aug 2003
    Location
    PA USA
    Posts
    8,396
    i dunno if it's all that simple to say one map versus another. For some reason, there do seem to be some of these bikes that get great gas mileage with the stock maps and some that do not. That FPR mod will likely help the latter.

    With the fuel mileage mine has always given, it won't ever be on my to do list.

  10. #10
    apriliaforum expert Motech's Avatar
    Join Date
    Aug 2006
    Location
    Santa Cruz, CA
    Posts
    3,157
    Quote Originally Posted by deefred View Post
    Motech, you still think you know better than both Aprilia and Triumph.
    Not really. I'm confident they know better now.

    Quote Originally Posted by deefred View Post
    For some bikes the FPR mod seems to work well. Its worth a try especially if you dont have tuneecu to reduce the IFT.
    I agree. That is why I've performed and recorded results of all my mods since the first one back in the original FPR thread in conjunction with TuneECU. I've found it makes a stock-map 2001 run worse, does wonders for stock 2002-2003 maps, and does little more than a slight increase in MPG with 05 map.

    I have not tried it with modified maps or H-piped bikes, so there you go.
    Last edited by Motech; 07-12-2019 at 04:24 PM.
    No Matter Where You Are, There You Go!

  11. #11
    apriliaforum expert Motech's Avatar
    Join Date
    Aug 2006
    Location
    Santa Cruz, CA
    Posts
    3,157
    Quote Originally Posted by RAS View Post
    i dunno if it's all that simple to say one map versus another. For some reason, there do seem to be some of these bikes that get great gas mileage with the stock maps and some that do not. That FPR mod will likely help the latter.

    With the fuel mileage mine has always given, it won't ever be on my to do list.
    Yah, but you're an mpg freak!

    I believe those (like you) getting such high fuel economy (and sometimes tire tread life) are the difference, not the bike. My current 2002 is a prime example, which also happens to be the first FPR mod I recorded back in the first FPR thread, before I owned it.

    Previous owner saw consistent returns of 36 to 42 MPG depending on his riding style. After the mod, his efficiency exploded to upwards of 50 MPG! (He'a a very swift rider, but very smooth, carrying fast entry speed and low RPMs, rarely exceeding 6K)

    A few years later, I bought his bike and never could squeeze better than mid-30s MPG. I (sometimes) ride as swiftly as he, less smooth though, and tend to carry higher entry revs approaching 8K, with 10K exit.

    It's all in the smoothness, and I'm certain you're much smoother than most RAS.
    Last edited by Motech; 07-12-2019 at 04:25 PM.
    No Matter Where You Are, There You Go!

  12. #12
    apriliaforum Member StreetCred's Avatar
    Join Date
    Jun 2006
    Location
    Wisconsin
    Posts
    182
    Alright gentlemen. . . Back on to the original topic. ME! Just kidding. . . So, I've looked over the plumbing and replaced some more rotten, cracked cables. I've got the bike running, although not that well. I don't think I have everything where it should be. The following should atest to that.

    Plumbing Status:
    - FPM is not connected to anything.
    - The "Y" junction it was connected to is open.
    - The hoses going to the throttle bodies go to a "T" connection with the hose coming off the "T" plugged.

    I've experimented with the FPR mod and other connections/disconnects and this is the configuration that the bike runs with. All other configurations kill the motor immediately there is any throttle. Some times it even pops out the top of the throttle bodies.

    I'm going to try a few different maps this afternoon to see if I can get it running better. I do have an appointment at a local mechanic that has a dyno. There's nobody else around in my area that would touch an Aprilia. All the dealerships are gone.
    StreetCred

    2003 Silver, wiring mod, fuel line mod, de-restricted airbox, HoMade exhaust.

  13. #13
    apriliaforum expert RAS's Avatar
    Join Date
    Aug 2003
    Location
    PA USA
    Posts
    8,396
    there's a pict in this link that will help a bit https://www.apriliaforum.com/forums/...ghlight=tubing

    1st, i don't think mine will run with the air box open. Dunno why that would be, but iirc from a time I wanted to spray carb cleaner down the TBs, it just wouldn't run.

    The hose from the FPR goes to a Y that splits off to the ECU and then crosses over to a drain in the bottom of the air box, right next to the stepper IAC.

    dunno where the hoses that T off to the access tubes for measuring TB balance go when they continue downward into the bowels of the beast - sorry.

    yer gonna have to check TB sync when this is sussed. One screw will stay closed and the other will do the balancing. Doesn't matter which winds up closed.

Similar Threads

  1. My bike won't fire.
    By tuonotommy in forum RSV Tuono, Tuono R, Tuono Racing, and Tuono Factory (2002-2005)
    Replies: 8
    Last Post: 12-21-2004, 01:28 AM
  2. Im new...and my bike won't start!
    By bob_e70 in forum RS125 Euro-archive
    Replies: 24
    Last Post: 08-08-2004, 07:34 AM
  3. police just caught someone trying to nick my bike
    By tony532 in forum RS125 Euro-archive
    Replies: 30
    Last Post: 06-13-2004, 01:38 PM
  4. Dealer tried to Kill MY Bike!
    By bikpaintr in forum RST1000 Futura (all years)
    Replies: 22
    Last Post: 05-01-2004, 06:32 AM
  5. My SR70 won't run now
    By Joseph Pagan in forum Scarabeo 50, SR50, Mojito 50, Rally, Fly 50
    Replies: 9
    Last Post: 01-10-2003, 09:37 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •