348 - Check Your FPRs! | FerrariChat

348 Check Your FPRs!

Discussion in '348/355' started by vvassallo, Jul 1, 2021.

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  1. vvassallo

    vvassallo F1 Veteran
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    This probably applies to the 355 crew as well. Look, our cars are now 'round about 30 years old so we expect age related issues to come up - electronics, right? Before you dive into a complete replacement of all things Ferrari/Bosch/Manelli/etc. electronic, let's look at our Fuel Pressure Regulators.

    I have been trying to fix a low rpm miss in my car for months. I replaced everything electronic on the engine. Spark plug wires, ignitors, coil packs, spark plugs to name a few. I even swapped out ECUs and chips because I have duplicates of everything. I used Stabilant 22 on every connector I could find. Nada.

    Plugzit had an idea earlier that the FPR on the 1-4 side might not be doing its thing. That's because, using a timing light (remember those?) we determined that the stumbling cylinder was No. 1. Looking at the plug it was fouled. Checking the light, it seemed to fire inconsistently at low (sub 3000) rpm. The FPR has a return hose, fed by vacuum, that sends fuel that gets past the internal diaphragm to the intake, just above No. 1. Makes sense, yes, that the extra fuel floods that cylinder.

    So we checked it. Remove the vacuum return line and see how much fuel drips out. In my case, it poured out. Diagnosis: the internal diaphragm failed. We replaced it with a same age Ferrari part from another car. The same miss resulted. Checked that FPR and it had failed too. Hmm. Tried to install new replacement Bosch part (these are widely available for other makes) but it too failed - due to the part not being identical when it was advertised as such and a manufacturing defect we found. Chinese parts, go figure.

    We ordered a used Ferrari replacement part and the miss was lessened but returned shortly. After much head scratching we returned to checking out the "new" old part. Guess what, it had failed, but was probably broken before we installed it. Finally we installed another new Bosch replacement part (correct this time) and that was it. Problem solved.

    So what are the odds of that many failed FPRs? Pretty good if you figure that all the old used parts are the same age as the original part that failed. The moral of the story is don't trust the part especially if its used. They're old and are subject to the same time wear as the original. I think that every 348 owner should replace their FPRs now just to take this off the table of future issues. Saves months of chasing ignition problems that aren't there.
     
    26street, Mmckee, ernie and 2 others like this.
  2. Ferrarium

    Ferrarium F1 Veteran
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    #2 Ferrarium, Jul 1, 2021
    Last edited: Jul 1, 2021
    Had similar issue, this will help.
    https://www.ferrarichat.com/forum/threads/fpr-identification-and-my-ecu-code-1212-adventure.604758/

    If your looking for things to replace to maintain road worthiness and prefer to treat components as high time components and replace before failure, that are outside a major, here is my list.

    Fabricate bypass fan shroud for main radiator
    ⦁ *Inspect and properly splice connection on previous stereo install if needed
    ⦁ *Replace front grill with Challenge grill with cavallino #62126100 & #60032109
    ⦁ *Replace rear grill cavallino
    ⦁ *Buy 2 sets of spare Carrello fog light lenses
    ⦁ *Replace Third brake light
    ⦁ *Add cavallinoto ashtray
    ⦁ *Replace shift gate with slick shift gate Hill Eng
    ⦁ *Replace Shift knob Hill Eng
    ⦁ *Replace glove box strut OEM
    ⦁ *Replace all relays and fuses in foot well and bonnet panels OEM
    ⦁ *Stabilitant to fuses/relays
    ⦁ *Replace HVAC servo and fix flap with brass fitting OEM/Hill
    ⦁ *Replace Hidden fuse with glass bullet fuse
    ⦁ *Adjust interior door open latch
    ⦁ *Lube window rails
    ⦁ *Add Window accelerators (did nothing)
    ⦁ *Replace third brake light OEM #140568
    ⦁ *Replace third brake light brackets OEM #62216200 (very corroded)
    ⦁ *Replace License plate light assemblies & add new bulbs OEM #186180 (very corroded)
    ⦁ *Replace Right taillight bucket bulbs
    ⦁ *Replace both inside door side marker bulbs
    ⦁ *Replace Left taillight bucket bulbs
    ⦁ *Decorode & Stabilitant to MAF and clean MAF
    ⦁ *Replace all fuses under bonnet OEM
    ⦁ *Replace all fuses passenger foot rest
    ⦁ *Replace dash bulbs and add Stabilitant connections
    ⦁ *Decorrode HVAC panel interior connection and add Stabilitant
    ⦁ *Replace engine bonnet struts OEM
    ⦁ *Restore leather seats
    ⦁ *Powercoat Door sill rockers Satin Black and implement Stainless inserts
    ⦁ *Replace Center console plate with new OEM #146375
    ⦁ *Replace driver door AC vent with new OEM #62620800
    ⦁ *Replace Passenger door AC vent with new OEM #62620700
    ⦁ *Nickel plate SPARE door handles, Shift gate, Lock knobs, shift ball
    ⦁ *Replace dash instrument panel OEM #147141
    ⦁ *Replace Speakers JL Audio CX2
    ⦁ *Source 2 cars worth of OEM gold/brown Wilton Wool carpet - @Reoriginals (foot mats, spare for wear etc)
    ⦁ *Replace window switches OEM #144797 & OEM #144798
    ⦁ *Replace window switch plates OEM #62158700 & OEM #62158800
    ⦁ *Replace door mirror switch Alfa Romeo #60529884 / OEM #134414
    ⦁ *Recover doors with OEM leather (Classic Coach Repair)
    ⦁ *Replace glove box, trunk, cabin bulb OEM
    ⦁ *Replace rear side marker bulbs
    ⦁ *Replace Headlight bulbs
    ⦁ *Rebuild steering rack and tie rods inner & outer and fab new inner rack bushing
    ⦁ *Replace steering rack mount bushings OEM #135139
    ⦁ *Rebuild front suspension bushings & ball joints (Parts from AW Italian)
    ⦁ *Replace front sway bar bushings and end link bushings (Parts from AW Italian)
    ⦁ *Inspect and Grease front wheel bearings
    ⦁ *Seal Thermocouple ECU casing with RTV (new condition)
    ⦁ *Replace Cutoff valves and hoses and clamps #147390
    ⦁ *Replace Check valves and hoses and clamps #148494
    ⦁ *Replace anti evap valve and hoses and clamps #130978
    ⦁ *Replace both radiator fans 12" SPAL #30102038 & 9" SPAL #30102038
    ⦁ *Replace COOLING FAN SENDING UNIT OEM #158655
    ⦁ *Source and install heat shield OEM #63547900
    ⦁ *Replace Temperature Sender OEM #104628
    ⦁ *Replace Coolant Temp Sensor OEM #125769
    ⦁ *Replace Throttle Position Sensor BOSCH #0280122004
    ⦁ *Replace Oil Pressure sender OEM #135940
    ⦁ *Replace hose clamps/ nuts/ washers/ studs as needed
    ⦁ *Replace four 90 bent radiator hoses and IAC hoses OEM #136513/122219/143270
    ⦁ *Replace both O2 sensors BOSCH #0258003222
    ⦁ *Replace both Catalytic Thermo-couples OEM #144270
    ⦁ *Replace both Crank Positions Sensors OEM #130975
    ⦁ *Replace HVAC Engine Auxiliary Water Pump BOSCH #0392020039
    ⦁ *Source new Flywheel (billet form MD Clutches)
    ⦁ *Source MD Clutches (Voith rebuild kit / clutch rebuild and grease etc)
    ⦁ *Source new spare HVAC control panel OEM #151711
    ⦁ *Source Male/Female door AMP plugs OEM #142687 & 142688
    ⦁ *Install PWM controllers for both radiator fans TOYOTA #89257-30060
    ⦁ *Replace dual can exhaust with Spider OEM #156072
    ⦁ *Replace Thermostat and seal OEM #105192 & 130346
    ⦁ *Replace both Ignition Control Modules BOSCH #0227100200
    ⦁ *Replace both ignition Coils BOSCH #0221503407
    ⦁ *Replace both Ignition Module covers OEM #150631
    ⦁ *Replace cam phase sensor OEM #146312
    ⦁ *Replace 3 fast idle SOLENOID VALVE and hoses OEM # 111704
    ⦁ *Replace Both IAC OEM #142432 - BOSCH #0280140505
    ⦁ *Replace Both MAF OEM #136374 - BOSCH #0280212018
    ⦁ *Replace both FPR STANDARD MOTOR PRODUCTS #PR161 (No BOSCH available)
    ⦁ *Replace both Fuel Pump BOSCH #69410
    ⦁ *Replace both Fuel Pump Anti-Vibration Pad OEM #126807
    ⦁ *Replace both Fuel Pump Gasket OEM #153188
    ⦁ *Replace both fuel supply hoses OEM #133967
    ⦁ *Replace both fuel return hoses OEM #133968
    ⦁ *Replace 8 fuel pump wire boots OEM #130146
    ⦁ *Replace all related fuel pump o-rings seals and crush washers (see diagram)
    ⦁ *Refurbish Injectors Mr. Injector
    ⦁ *Refinish fuel rails new powderoat
    ⦁ *Source NEW ABS Pump and Accumulator TEVES #10.0511-9023.1 / JAG #JLM1885
    ⦁ *Source NEW ABS pump union kit OEM # 70000509
    ⦁ *Source NEW ABS pump Mounting kit from Ferrarichat member (User-C3)
    ⦁ *Source NEW ABS pressure switch DELCO #ACDELCO 25530882
    ⦁ *Replace front shock bushings OEM #130516
    ⦁ *355 Wheels
    ⦁ *Fuel Injectors BOSCH # 0280150731 - Not available, cleaned and refurbished instead
    ⦁ *New Brembo Front disc - 160051B
    ⦁ *New Brembo Rear disc - 160052B
    ⦁ *Ferodo DS Performance Brake Pads Set of 4 70000875/FDS
    ⦁ *Replace brake lines with StopTech SS brake lines
    ⦁ *Flush brake/clutch and refill with Motul RBF600
     
  3. marknado

    marknado Rookie

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    Interesting, what's the consensus on which FPR to replace original units with? new Ferrari is $867, SMP PR161 is $77. Get what you pay for? or is the SMP a good unit.
     
  4. 308 GTB

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    #4 308 GTB, Jul 1, 2021
    Last edited: Jul 1, 2021
    Mark,

    My 1995 F355 Challenge had to race in the Ferrari Challenge Series with its OEM fuel pressure regulators. When it was no longer eligible for the Series, it raced in SCCA with Aeromotive adjustable FPRs...


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    A couple of years ago, we switched to a single heavy duty adjustable Aeromotive FPR with an indwelling fuel pressure gauge...


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    My car runs much better now. I highly recommend Aeromotive FPRs.

    Barry
     
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  5. marknado

    marknado Rookie

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  6. 308 GTB

    308 GTB F1 World Champ
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    Those might be appropriate for your 348, Mark. My heavy-duty FPR is the Aeromotive 13101 EFI Regulator, A1000 Injected Bypass - Adjustable with similar specifications as the ones you found:


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    • Base pressure adjustable from 40-75 PSI.
    • Gasoline and alcohol compatible.
    • Fuel pressure rises on a 1:1 ratio with boost.
    • 1/8' NPT gauge port.
    • P/N 13101 provides (2) ORB-10 inlet ports and (1) ORB-06 return port

    The all black A1000 Injected Bypass - Adjustable FPRs you found will not be as noticeable in your engine bay.
     
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  7. SoCal1

    SoCal1 F1 Veteran
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  8. SoCal1

    SoCal1 F1 Veteran
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  9. marknado

    marknado Rookie

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    #9 marknado, Jul 1, 2021
    Last edited: Jul 1, 2021
    Haha, what pressure do you run Tim? It will be interesting to see where ideal is on a wideband. Early 348 is 3.0 bar and later 3.8. I assume injectors are the same and mapping is changed to suit between the years?
     
  10. steved033

    steved033 F1 Veteran
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    While you're at it, clean the MAFs. I chased a random miss on 5-8 last saturday. Car would run fine, then not fine, then fine, the whole bank would drop. Seems to have been the MAF. I sprayed it out, and everything cleared up.

    I replaced my FPRs when I did the rest of my fuel system early this year.

    sjd
     
  11. m.stojanovic

    m.stojanovic F1 Rookie
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    The Bosch cataloge shows the following FPR numbers and application:

    348 & Mondial..........(->10/90)........0 280 160 715.......137960.......3.0 Bar

    348............................(11/90 ->)........0 280 160 731.......137960.......3.0 Bar

    Mondial.....................(11/90 ->).......0 280 160 738.......147281.......3.8 Bar

    According to Bosch, the change at end of 1990 was only to the Bosch p/n and not to the pressure. However, it seems that some 348-s after 1990 (possibly only some spiders) had 3.8 Bar FPR-s, as what was used on Mondials. The good thing is that the 348's 3.0 Bar FPR Bosch 0 280 160 731 was also used by Volvo 960, S90 & V90 (91-98), Volvo p/n 3547653, and in Saab 9000, p/n 7584063, still available from Volvo/Saab parts suppliers at ~80 USD.
     
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  12. Ferrarium

    Ferrarium F1 Veteran
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    Also, for the 3.0 bar it is STANDARD MOTOR PRODUCTS #PR161 (No BOSCH available)
     
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  13. m.stojanovic

    m.stojanovic F1 Rookie
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    3.0 Bar Bosch is available (Bosch 0 280 160 731, Volvo/Saab part as I mentioned above). The 3.8 Bar Bosch 0 280 160 738 may not be available as a part for other cars. The equivalent Standard FPR-s should be as follows:

    0 280 160 715.......3.0 Bar.......PR161

    0 280 160 731.......3.0 Bar.......PR161

    0 280 160 738.......3.8 Bar.......PR298
     
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  14. SoCal1

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    #14 SoCal1, Jul 2, 2021
    Last edited: Jul 2, 2021

    I run my own ECU mapping and change out between 3 sets of injectors. Bigger throttle bores right now , next setup full ITBs .I never run the same setup :)

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  15. vvassallo

    vvassallo F1 Veteran
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    Yes, one can swap out the stock fixed pressure FPR for adjustables or do a conversion to a single unit, however I believe that these are not street legal in CA. Regardless, your fuel pumps are rated to 65 psi and the 3.9 bar delivers 55 psi to the fuel rails and injectors. Interestingly, most injector flow calculations are based on 45 psi so by that token, our systems are above spec. With an adjustable FPR you can increase fuel delivery by upping the pressure - to a point. I am trying to remember where we sourced the new FPR. It is chrome colored, not cadmium like the OEM part. I believe they are sourced from a Volvo, Lancia or some other vehicle we neve got in the US.
     
  16. vvassallo

    vvassallo F1 Veteran
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  17. Ferrarium

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  18. AceMaster

    AceMaster Three Time F1 World Champ

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    Can you post the part # and source? I will add to the 348 Parts thread
     
  19. vvassallo

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    Will do. Haven't found it yet. Might need to ask Plugzit for it. Later 348's use the 3.8 Bar version, and it is a good idea to upgrade them in the older cars.
     
  20. Ferrarium

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    To do that you need new braided fuel lines as the the barb/threaded ends are different.
     
  21. m.stojanovic

    m.stojanovic F1 Rookie
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    I believe that the 348-s that had 3.8 Bar FPR-s had different ECU-s programmed to work with 3.8 Bar fuel pressure. Simply putting 3.8 Bar FPR-s to work with ECU-s set for 3.0 Bar is not an upgrade. The "3 Bar" ECU will not "know" the FPR-s are 3.8 Bar so it will still command injectors open times as with 3 Bar pressure but more fuel will be injected during that time if the fuel is at 3.8 Bar = rich running. The ECU will trim the mixture down based on the the O2 sensor signals but the question is whether it will be able to cope with so much extra fuel. In any case, by just increasing the fuel pressure you get no benefit.
     
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  22. Ferrarium

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    Unless you change the ECU chips to the Spider chips. One would need to do both.
     
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  23. vvassallo

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    Update: After doing a quick dyno run to check on my build progress, it became clear that I need a bit more fuel. The dyno tech and my fuel injector tech both suggested amping up the fuel pressure before doing anything else, like new higher flowing injectors. Our fuel pumps allegedly can deliver 70 psi if necessary, not that I want to go there.

    So I bought a couple of new FPR's like Tim's. It was pretty obvious that they just don't swap in for the stock ones. So I am doing a complete install from the fuel pumps up. So far no issues using AN pipe fittings, etc. I got my stuff from Earls who were very professional and knowledgeable, although curt.

    The problem is that I have an issue connecting the fuel rail to the new FPR because of the end fittings on the rail. They are not AN fittings, although they look like them. See the pix below.

    The first shows the Aeromotive FPR I am using. It has 3 ports and a tap for a gauge, which I have. We are only using one inlet and the return so the 2nd inlet is capped with the blue AN pipe plug (3/8ths pipe or 9/16ths wrench, if you prefer). The return is going back to the fuel pump (left); the inlet comes from the front of the fuel rail (facing the engine firewall) at the top of the FPR. This is for the driver's side, BTW.

    The second picture presents the dilemma: You cannot simply attach an AN6 line with female connectors to the fuel rail because that is a different fitting. My research says it is a 14 x 1.5 mm 60 degree metric cone fitting. Kind of like a upgraded brake line fitting with something looking like an AN connector. There is no such thing as an adapter to 3/8ths pipe or AN6. How would you guys suggest getting this done? I have researched adaptors until my mind is numb and I cannot figure out an easy way to do this. I think Tim did this a different way, not routing through the FPR like I am trying.


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  24. SoCal1

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