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4.9L fuel starvation. FACIT fuel pump failure?

Discussion in 'Maserati' started by 71Satisfaction, May 8, 2013.

  1. 71Satisfaction

    71Satisfaction Formula Junior

    Jul 15, 2012
    533
    New York & Norway
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    Art
    Good morning,
    I ask for any thoughts on the following:

    My Bora has a stubborn fuel starvation problem. The tests done by me and Dave Burnham's shop are somewhat inconclusive, but I'm suspecting an internal intermittent failure of the FACIT fuel pump:

    Driving the car, it bogs down and even stalls out from fuel starvation, at what appear to be completely random conditions:
    - 3,000rpm in 5th on the highway.
    - 2,500rpm in 4th on back roads.
    - Uphills.
    - Downhills.
    We can't find a clear 'commonality' in any particular starvation "event". I can flog the car for 10-15 minutes without a stall, and it will stall 5 minutes later on a gentle country road. But I can't go a day without it. I'll be driving along and the engine stops responding to throttle..

    FINDINGS to DATE:
    - The first times out last year, the fuel pressure would recover by putting the ZF in neutral and throttle at idle. Then I could keep it running, or if stalled - restart the car. This situation we ascribed to the fuel pump not being OEM spec.
    - We removed the two previous pumps that were not up to OEM spec.
    - We bought and installed one new OEM Facit from MIE.
    - I still experienced intermmitent fuel starvation and stalls.
    - We inspected the fuel return port from the fuel rail - it is free and clear.
    - We tried with the fuel filler cap off and on - in case the tank wasn't venting. It makes no difference.
    - The fuel pump gets proper voltage (12.56-13.41) in all driving conditions.
    - We bypassed the fuel filter/press regulator. Fuel pump feeding directly to the fuel rail and return port. This made no discernable difference.
    - Leaving the filter/regulator off, I have mounted a fuel pressure gauge between the fuel pump and the fuel rail.
    - Turning the key to 'ignition', the pump pressurizes up to 5-6psi. Sometimes it stays there until engine start, other times the rise to 5-6psi is immediately followed by a drop to near zero (0+). [Why? Does the Facit have some internal over-pressure protection?]
    - The engine always starts no matter the indicated pressure.
    - Upon engine start and idle, pressure varies between 2-3psi and nearly zero (0+).
    - MOST OFTEN the gauge reads continuously 0+ (near zero) during any given drive.
    - It can stay at 0+ for quite some time in various throttle and load conditions with no adverse effect on driving.
    - However, about 20% of the time, after a fuel starvation event and restart of the engine, the gauge will spike to 5-6psi, then settle down on 1psi in all regimens for 10-15 minutes before returning to 0+. This seems an anomaly to me. Why in only some cases, with no change, would the pressure come up to 1psi?
    - At the onset of starvation, putting the ZF in neutral: 80% of the time the engine stalls out. Sometimes the pressure remains at 0+ but the engine doesn't quit. And sometimes the pressure spikes to 5-6psi, then promptly drops to 0+.
    - At the onset of starvation, taking my foot off the throttle: 50% of the time the pressure recovers and spikes to 5-6psi and the engine stays running, 40% of the time the engine stalls... 10% the pressure stays at 0+, but the engine comes back to life without a stall.

    80% of the time when driving the car normally, the pressure gauge reads 0+.

    The problem is trending towards getting worse - it used to happen maybe once every 25 miles, now it's once every 8 miles or so. This could be a 'commonality' - distance or time. Leaving us to suspect some condition that builds up over time. Like tank pressure (which we eliminated)... or a hidden clog in the fuel plumbing?

    Your thoughts (or sympathy ;-) are welcome.
    Best,
    -Art
     
  2. staatsof

    staatsof Five Time F1 World Champ
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    Methodically go through the entire fuel system. It's an old car and you probably don't really know how it's been maintained.

    That means from the tank to the carbs.

    I switched out my Facet pump early on but there is nothing wrong with them.
    I have one on my Espada. Nothing wrong with buying them from MIE but they are readily available in all the various configurations from good marine stores at very nice prices. Did you verify that the pump is the correct one. Call Facet in Elmira. It doesn't sound like that is your problem though

    Assuming it is a fuel problem you're experiencing then you've missed something but if I had to hazard a guess maybe you've got junk in the fuel tank that is sloshing around and blocking good fuel flow at times. It should show up in the filter.

    Check the on pump filter. If crap is in the tank you should see it there.
    You could drain the tank, pull the fuel gauge sender and insert a borescope to have a look see.

    Check you pressure regulator as well. I ditched the glass bowl one many years ago when one of them in my friends Countach had the pushed in fuel fitting drop out of the body of the regulator while driving. :eek:

    Don't drive the car if it's getting this lean.

    I've never dropped the tank with the engine in the car but I think it will come out OK.
     
  3. VeloceOne

    VeloceOne Karting

    Jul 18, 2007
    87
    On the regulators that I have, the filter is not only pressed on but held in place by a spring on the bottom. (Between the bottom of the bowl and the filter) They will not drop out of place. Regards Ian
     
  4. MK1044

    MK1044 F1 Veteran
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    I'd guess that or clogged fuel line.
     
  5. staatsof

    staatsof Five Time F1 World Champ
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    Not the filter element. It was the actual inlet and outlet pipes which were pressed into the pot metal body.
     
  6. staatsof

    staatsof Five Time F1 World Champ
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    BTW Art don't run the pump without a regulator. Not good for Webers.

    The Bora uses a return line off the front of the fuel rail that drips fuel through a small orifice back into the tank. If you turn on the ignition key , open the fuel cap you can hear what sounds like a little boy taking a leak.

    You don't need fuel pressure to start the car, just full bowls.

    I think your tank has got crude in it that is obstructing the fuel flow. Some of it may now be in the fuel lines.

    I had this happen to me and it stranded my wife and I in a flea bag hotel for a night with no luggage. I had to fix the tanks.

    Keep plugging. There's nothing special about the Bora except that it's pretty old now.
     
  7. ColdWater

    ColdWater Formula Junior

    Aug 19, 2006
    621
    bicoastal USA
    Sounds very similar to the problem I had with a Giulietta SS that had been sitting for a few years. In the Alfa there is a separate filter in the tank outflow made of brass screen. This had corroded and broken down (ethanol damage ?). The fragments sloshed around and intermittently clogged the fuel line. Draining the tank and line and a new screen resolved the problem.

    Hi to Dave and Carter (they'll remember my absinthe ID-19).

    Don
     
  8. AM1220552

    AM1220552 Karting

    May 25, 2012
    132
    Have you checked the voltage at the pump? You might be suffering from voltage drop, meaning the pump is not giving a constant correct feed.


    Brgds

    Kim
     
  9. f308jack

    f308jack F1 Rookie

    Jun 7, 2007
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    Jack Verschuur
    When this occurs and the engine stalls, did you check if the carbs ran dry or not? Does she fire up immediately after such an event, or do you have to wait for the pump to fill the carbs?

    The system is really rather simple.

    You have a pump, which in order to function properly needs fuel and electricity. Make sure that both are in ample supply. Measuring 12.X Volts says something, but does the elec cirquit offer the current that the pump needs at all times?

    Make sure the tank, in-tank screen, lines are free from debris, make sure the rubber hoses are intact and not internally collapsed and fuel filters clean..

    Make sure there is enough fuel in the tank. A system that circulates can warm up the fuel in the tank, and if hot enough (very little fuel) can cause vapour-lock situations.

    Of course difficult to judge from a distance, but given the randomness of the problem I would actually lean towards an electrical problem, especially since you can also flog the car without mishap most of the time.

    Best,

    Jack.
     
  10. staatsof

    staatsof Five Time F1 World Champ
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    He's already posted that the voltage is OK. If there isn't enough amperage delivered under load the voltage would drop and would easily be observed if he's also monitoring this when the event occurs. If you want to be certain that it's not electrical in nature external to the the pump you could always run a non switched direct feed and take a drive. I've had to do that with one of my other cars in an emergency.

    I don't remember an in tank fuel screen on my car and I had the entire thing all apart. The parts diagram doesn't indicate one but there are things on that diagram which are different from how my car was originally configured so things could vary.

    There are versions of the Facet pump available with an internal cut off valve so that no fuel will flow through it when it's turned off. Perhaps this IS the failure point?
    But the correct version of the pump for this car wouldn't come with one.
    There's no reason that I can think of for having that feature on this car.

    Art, I think you should dead head the pump before the fuel rail but after the pressure gauge and just turn it on to see how the pump behaves. You could even insert a valve so that you could periodically open and close it to allow fuel flow through the rail and back into the tank. Perhaps this will allow you to trigger an event?

    When I had all the rust come loose in the tanks of my Espada it clogged up the filter of course and produced somewhat similar issues as you describe though I knew in one tortuous afternoon and night what was wrong so I didn't have nearly as enduring a mystery as yours.

    Once I rectified the tanks I found that the pump (a new one before the filter impact) had been damaged and would no longer provide enough fuel flow for the engine. I actually measured it's capacity under a pressure load.

    So it is possible that you pump is bad. But why? Call Facet.

    It's possible that a large piece of debris is periodically blocking flow but never exiting the tank. So I'd still check out the tank and have a look to see if junk is reaching the filter in the pump.

    On the Espada the tanks feed the pump and then the main filter is after the pump which is a little different than the Bora. It also has no fuel pressure regulator in stock configuration! :eek:

    You sure are getting plenty help from everyone. Good luck.
     
  11. 71Satisfaction

    71Satisfaction Formula Junior

    Jul 15, 2012
    533
    New York & Norway
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    Art
    Thanks gentlemen,
    The deafening silence from my end is due to some family visiting.

    In response to your suggestions, we're sourcing a borescope to inspect the fuel tank and it's outlet. It seems a likely culprit.

    We HAD thoroughly checked for debris in the system prior to the initial engine start last Summer and found to trace, perfectly clean everywhere. We did not want to crud up the new fuel pump and freshly rebuilt Webers.

    But.. she's been on the road for 700 miles and I did find a light dusting of red debris in the filter bowl upon inspection today (similar to the red "slushing" product I have used to seal aircraft fuel tanks...hmm...).

    In related news, I gave rides to each of my Norwegian family in the Bora today, she rose to the occasion and only bogged once all day. Or was she just respectful of the Vikings?

    I will report our findings in the tank.
    - Art
     
  12. staatsof

    staatsof Five Time F1 World Champ
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    Art when I was going though my travails with the Espada I had just rebuilt the carbs which were a huge mess and rebuilt/modified the distributor. So I had multiple things to look at. I ended up adding one of these just before the fuel manifold. It's easily cleaned and you can see what's collected.

    Aftermarket, KTM, & 10 Micron Fuel Filters in California | GS Performance Inc #40

    It's a nice well made piece.

    On the Bora I would mount that under the RH carpeted panel near the outside edge in the engine compartment to keep it out of the direct heat. I have used metal style FI style filter in that spot on my Bora.



     
  13. f308jack

    f308jack F1 Rookie

    Jun 7, 2007
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    If you want to know what comes out of your tank, just buy one of these cheap plastic in-line filters and place it between tank and pump. Drive the car around a bit, and cut the filter open. Cost is a few Dollars.

    If the parts manual shows no in-tank screen, the screen in the pump should be inspected as well, if there is one. I always wondered how many cars run with basically no protection for the pump.

    How is the flow from the return-line to the tank restricted? Another possibility could be that there is debris there, temporarily obstructing flow back and causing over-pressure and vast over-fueling?

    Best,

    Jack.
     
  14. MK1044

    MK1044 F1 Veteran
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    I wonder if rusted out fuel tank internal baffles might be the culprit here? Fuel sloshing away from the pickup would certainly lead to fuel starvation.
     
  15. 71Satisfaction

    71Satisfaction Formula Junior

    Jul 15, 2012
    533
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    Art
    Hello all,
    Time for a positive update. Problem solved. Larger fuel pump.

    I siphoned the fuel tank for an inspection, it was completely clean, no rust, no debris, baffles are all intact and perfect. No debris in Facet pump's internal screen, no debris in filter between tank and Facet pump. I revised some of the fuel hoses in and around the filter and Facet fuel pump (34gph, 6psi). Put everything back together, added some fuel and... no dice - I still got the bog by 3000rpm.

    Long story short: It was the Facet fuel pump. Stuart at MIE furnished me with an 'experimental' fuel pump he stocked in the event the regular Facet's weren't adequate. Never having tried it before, I was the guinea pig. It's a Holley knock-off giving 110gph 7psi.

    Installed it and never looked back. No bog. Fuel regulator keeps a constant unshakable 2.5psi to the fuel rail. Problem solved.

    This pump is no quieter than the Facet. It's a bit heavier, so I fabricated a stronger mounting bracket and rerouted the hosing and bottom filter to suit this pumps different port locations for the least amount of bends (& potential hose kinks). I've run it over an hour and it & the wiring doesn't get hot.

    Thanks for your input on this,
    Cheers,
    -Art

    P.S. - I'm looking forward to a drive with Peter Perry, Sr. and his yellow '75 Bora later this week.
     
  16. mfletch

    mfletch Formula Junior

    Nov 3, 2008
    480
    Art, thanks for posting your problem and solution. I am glad you figured it out. I am having a fuel starvation issue with my 59 3500. I replaced the fuel pump with a Holley, 4 years ago, when I first started restoring the car. I am wondering if I have a defective pump. Your problem makes me think it might be worth a try, before I start pulling my rebuilt carbs apart. Thanks again.
     
  17. staatsof

    staatsof Five Time F1 World Champ
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    So you had the wrong pump in the car to begin with?

     
  18. 71Satisfaction

    71Satisfaction Formula Junior

    Jul 15, 2012
    533
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    Art
    Hi Bob,
    Thanks for asking - with the following I hope to illuminate the situation with my pump(s).


    1. Brief answers for those who wish to get back to bed:
    - No, the Facet pump I had was "right" because it meets factory specs.
    - Yes, it was the "wrong" one because if a Holley pump solves the problem it implies the Facet didn't work.
    I believe the new Facet pump I had installed was a failed part from the factory.


    2. Background for those staying up late anyway - a.k.a. "The Full Monty":

    The Facet pump (part #480-532E) in my Bora was purchased new from MIE in October last year. According to Dave Burnham Citroen, the new Facet pump they ordered from MIE met factory specs. At that point in time, the fuel starvation problem improved by virtue of being intermittent instead of constant with onset between 2,500 and 3,000rpm. I note the fuel pressure gauge I installed always indicated low pressure (1.0-to-0.5psi) even when there were times the Bora didn't starve and bog down for 20-30 sometimes 40 miles of hard driving.

    When I initially came to suspect the new Facet fuel pump, I first checked for correctness: The Facet part #480-532E is Facet's highest capacity "High Perf. Gold Flo" pump; 45gph at 6.5-8.0psi. I called Facet Tech Support about the possibility of their pump having failed prematurely. I got a big yawn. Facet Tech was not forthcoming with information about frequency of failure of their pumps, common mistakes overlooked by customers, failure modes, troubleshooting, etc.

    So I looked elsewhere until it seemed the most likely problem was indeed the new Facet fuel pump.

    I called MIE and talked with Stuart about it. We made a deal for a HD pump he had placed in stock to address such a situation as mine. Stuart's pump is now in my Bora, which no longer suffers fuel starvation or fuel pressure deviations. The bog is banished and fuel pressure stays pegged at 2.5psi. This pump is heavier than the Facet and isn't ported at the same locations, so I fabricated a stronger bracket which also oriented the pump and hoses for best "geometry". This pump isn't quieter, nor is it much worse.

    Personally, I believe the "correct" Facet pump was a failed part from the factory. I'll see what MIE might be able to do about that situation.

    I hope this is useful.
    Best,
    - Art
     
  19. eogorman

    eogorman Formula Junior

    May 10, 2005
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    Pleasanton, Ca
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    I had a long discussion with the Weber Carb people in Giroy, Ca ( Pierce Manifolds). They advised they have seen a lot of problems with the Facet pumps in the past five years. You can get a good one but they have seen several defective ones even though they are new. He has a test bench and has tested several of the pumps so he has a excellent background to substantiate his belief. He also reccommends the Holly motor pump. You do need a good pressure regulator to keep the fuel pressure under 4 psi. I have had a Holly motor driven pump on my Bora for more than two years and have had no problems with it. I have three new Facet Pumps but installed the Holly because one of the Facet pumps failed when I was away from home and it was easily available from a local auto parts store.
     
  20. 2NA

    2NA F1 World Champ
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    I've seen those pumps fail right out of the box.
     
  21. staatsof

    staatsof Five Time F1 World Champ
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    #21 staatsof, Jun 28, 2013
    Last edited: Jun 28, 2013
    OK Art. Thanks for the clarification.

    It sounds like Facet is have quality control problems. That's pretty scary for any airplane users out there ... The one in my Espada is just fine though I did have the first one fail after the system became impacted with a LOT of rust from the tanks. I attributed that to the rust. I discovered it's sub par performance, not meeting it's own specs, by actually measuring the flow.

    But after hearing a couple of these stories now I'm wondering if I just got a bad one too?

    Seems like they got some splainin' to do.

    Just shows you Art, you have to be ready the check everything solving some of these pesky problems.

    Now enjoy the car. Sorry you had such a PITA introduction.

    Sometime I'll tell about my really mysterious 2 year issue that had me sending carbs for flow testing in the middle of the LA riots.
    We'll need to get a bit drunk first ...

     
  22. 71Satisfaction

    71Satisfaction Formula Junior

    Jul 15, 2012
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    Those are interesting anecdotes on the Facet pumps... thanks, Gents.

    LOL, thanks Bob - the introduction has been manageable, I've enjoyed the Bora regardless.. I think we all develop a special frame of mind to deal with these things...

    ...a few Gin & Tonics would be nice in this weather.

    Hmm.. aircraft.. I didn't know Facet produced aircraft fuel pumps. I'm confident they meet much stricter QC requirements. I used to own and fly a '46 Ercoupe 415C, and I'm glad it's Continental 75 had a mechanical fuel pump.

    Onwards!
    -Art
     
  23. staatsof

    staatsof Five Time F1 World Champ
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    An interesting follow up story. Another Maserati Ghibli owner has a starvation problem with a pair of replacement Facet pumps, one pump at a time from each tank, but he was directed to the wrong pump by Facet - 32GPH. Apparently someone at Facet doesn't know their s**t these days ... :rolleyes:

    So now he has to exchange a pair of them for the 480532 models.

    Caveat Emptor on info guys.

    I do wonder if Art's pump was mislabeled at the factory? Mine has been fine for 5 years.
     
  24. jnk

    jnk Formula Junior
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    Nov 12, 2010
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    Can anyone tell me the correct model number of the red top Facet fuel pumps that I need for my 1971 4.7 Ghibli
     
  25. JulianMerak

    JulianMerak Formula Junior

    According to the post above its a Facet 480532 which are on EBay. I have the original Bendix pumps still on mine which I think are past it and need replacing too
     

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