400iA running like crap! | FerrariChat

400iA running like crap!

Discussion in '365 GT4 2+2/400/412' started by 400iGuy, Mar 2, 2014.

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  1. 400iGuy

    400iGuy Formula 3
    Owner Rossa Subscribed

    Aug 26, 2004
    1,055
    Central Florida
    Full Name:
    Al
    Hopefully someone may recognize the symptoms that just appeared in my 1984 400iA.

    We've had a home remodeling project going on since the early December so I had my 400iA and ’34 Ford coupe in a friends storage building so I could fill half of my garage with furniture and other stuff from the house. The project is completed so yesterday I went to bring the Ferrari home and at first all was well. I took the car cover off, unplugged the Battery Tender and it fired right up. It sat there idling while I folded the cover and put it in the trunk and talked to my friend. It must have idled for 10 minutes. Then I headed for home and it was running perfectly. I drove about 5 miles and stopped at a gas station primarily because the late afternoon sun showed that lots of dust had come thru the cotton car cover and it was difficult to see. So I stopped to clean the windshield and while there I filled it with 93 octane (it was ½ empty).

    Then the problem started. For the first time in 12 years it wouldn't start immediately. I ground on the starter and it finally caught and chugged along barely running. In time I could work the revs up to 1500-2000 and it cleared up. So with some effort I was able to get it moving and slowly got it up to 2000 RPM and drove it back the 5 miles to my friend’s house. Over 2000 RPM it ran perfectly. I had a couple of traffic lights to deal with and if I slowed below 2000 RPM the problem reappeared and I had to slowly work the rpms back up. I parked it back in the storage building/garage.

    So I drove the ’34 Ford back home and now I’m puzzling over what the problem is and how to fix it. My first thought is I added bad gas but there should have been enough gas already in the system that it should have started and run briefly before any newly added gas could have an effect.

    Anybody ever experience anything like this? Is there something in the injection or ignition that changes at 1500-2000 RPM? Any suggestions on what it might be will be greatly appreciated?
     
  2. koisokok

    koisokok F1 World Champ
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    Dec 8, 2006
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    Had a similar time where the car was just running on 6 cylinders. The car would barely stay on unless I revved it up, and once I passed a curtain RPM it would take off! My fuel pump was leaking and found to be supplying low fuel ,volume and pressure. Replaced them with new Bosch fuel pumps. Hope this helps, I'm terrible when it comes to working on my cars. He also tuned the ignition and fuel system after, dont know if that is b.s. but just read it on my invoice.
     
  3. Ak Jim

    Ak Jim F1 Veteran
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    Dec 23, 2007
    8,451
    North Pole AK
    Don't automatically assume the problem is related to being stored, it could be completely unrelated.
     
  4. GT Jones

    GT Jones Formula Junior

    Oct 15, 2011
    669
    Lincoln, MA
    Full Name:
    Christian J
    whoa, R5 Turbo!
    Sorry to interrupt. As you were...
     
  5. new ulm 400i

    new ulm 400i Karting

    Sep 1, 2007
    116
    Taipei, Taiwan
    Full Name:
    Lee Atkinson
    ...may be a nice time to replace the filters and suction hoses underneath the car...even consider (unless you know if these have been replaced in the last 25 years...) the fuel pumps. Not that I think these will resolve your problem, but these are simple and old rubber is a leak waiting to happen...
     
  6. koisokok

    koisokok F1 World Champ
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    Thanks... :)
     
  7. koisokok

    koisokok F1 World Champ
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    I was charged $190 for two Bosch fuel pumps from the mechanic. So not bad at all. Labor is another story.
     
  8. markcF355

    markcF355 F1 Rookie
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    Jun 6, 2004
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    It sounds like one of your fuel pumps isn't running.
    Unplug the connector on the left fuel meter and turn on the ignition but don't start the engine.
    Both fuel pumps should now be running.
    Try to hear if they are.
     
  9. 335s

    335s Formula Junior

    Jan 17, 2007
    870
    SF Bay Area
    Full Name:
    T. Monma
    since this is a dual CIS car, test-don't guess...
    get a PAIR of K-jet guages, hook them up, wait overnight, try and start, see what pressures are doing
    cold, system and hot
    I dvise yiou to disconnect the power to the controp pressure gegulators, as the bi-metallic springs wiull shift pressures to hot quickly and you wont have time to poke around and make notes-all this does is make it runn full cold for a couple mins longer-and this will NOT hurt anything.
    after this, visual ck for leaks at pumps, filters, and accumulators(leaks from vent tube and you are hosed), as well as whats going on under the hood...
    THIS assumes you have ckd all electrical issues/relays circuits are proofed, etc...
     
  10. Jagbuff

    Jagbuff Formula 3

    Jan 13, 2004
    2,267
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    Franck
    ...is that your R5? Been looking for one in the US....
     
  11. 400iGuy

    400iGuy Formula 3
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    Aug 26, 2004
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    Thanks for the all the responses. Sounds like I have a lot of work to do. First I have to get it flatbedded to my house so I can start checking things out.
     
  12. koisokok

    koisokok F1 World Champ
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  13. Highmiler

    Highmiler Formula Junior

    Dec 8, 2010
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    Missouri
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    Greg
    I had exactly the same problem. See "The Right Bank" thread in this forum for the blow by blow. The final cure is to wire the pumps directly to the battery, by passing the fuse board. This delivers full voltage to the pumps allowing them to keep the proper pressure up.
    Greg
     
  14. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
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    Ken Battle
    If fuel pumps or filters are the issue, why will the car run at 2000+ RPM???? It needs more fuel then.

    It sounds like the distributor is stuck at 30+ degrees advance. Timing light under car is fun at rev's! My distributor was seized at low advance last fall.
    Ken
     
  15. markcF355

    markcF355 F1 Rookie
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    Ken, I'm sorry. I missed that. I think you may be right.
    I've seen these get moisture in the dizzy that gums up the weights.
     
  16. Highmiler

    Highmiler Formula Junior

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    Greg
     
  17. 400iGuy

    400iGuy Formula 3
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    That's a good idea Ken. I'll include looking at the distributor advance when I start working on it. It may be a week or two before I can do that.

    Thanks,
     
  18. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
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    Ken Battle
    With dizzy cap off see if you can rotate rotor by hand and if is snaps back. Snap is an exaggeration for this distributor as springs are soft compared to a Lucas and 30 degrees of advance is not a lot of rotation on distributor. It is subtle, but frozen is frozen.
    Ken
     
  19. 400iGuy

    400iGuy Formula 3
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    How do you get the distributor cap off?!!!! Do you have a universal joint in your forearm and extra joints in your fingers. Oh yea.and an eyeball on the end of your pointer finger so you can see?

    I checked the voltage at the pumps. 11.5 for each. Using a timing light I can see that all 12 plugs are getting fire. The advance mechanism is what makes the most sense at this point. And maybe arcing inside the dist.



    Sent from my iPhone using Tapatalk
     
  20. Highmiler

    Highmiler Formula Junior

    Dec 8, 2010
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    Greg
    That third cap screw nearest the firewall is a challenge but can be removed once you get the hang of it.
    I went down this same road. When you get the cap off the body and are looking for tracking inside the cap, notice the carbon contact in the center of the cap. Is it still there? Is it still spring loaded?
    Mine wasn't and I had to replace the cap. This produced a noticable improvement in performance.
    Plus, I now have a very impressive 13 place pencil holder on my work bench.
    Good Luck,
    Greg
     
  21. wrxmike

    wrxmike Moderator
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    Mar 20, 2004
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    Mike
    If spark is Ok, then it will be a fuel problem.

    Consider with a fuel pump not working or a filter blocked it won't be getting enough fuel, a problem that gets worse with increased fuel demand at high revs, not better. So its not going to be the fuel pump or filter, because the problem you descibe is poor running at low revs, ok at high.

    That implies too much fuel, because only at high revs can the engine cope with the excess fuel, whereas at low revs it recieves too much fuel ( stumbes, floods ). You can check this by pulling a couple of spark plugs form each side, one side will be much wetter than the other.

    To my knowledge the only thing that can cause this is a faulty warm up regulator (WUR ), this is the exact same problem I've had in my car, and its covered in another thread.
    Take it to a Bosch CIS specialist ( mid 80' Mercs or BMW's ) or buy a set of gauges from ebay and diagnose it yourself. The diaphram in WUR fails after time, so it sends the wrong signal to the CIS system, allowing maximum fuel flow.

    Basic CIS Fuel Injection Pressure Tester for Bosch CIS Auto Car Mechanic Tools | eBay

    M
     
  22. Highmiler

    Highmiler Formula Junior

    Dec 8, 2010
    414
    Missouri
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    Greg
    Here is the US "go to guy" for the Bosch CIS system. His name is Larry Fletcher and he is from coastal Alabama I think. If you have the problem Michael describes you will need to get aquainted with Larry. He is very helpful to Ferrari guys.
    Greg

    <[email protected]?
     
  23. 400iGuy

    400iGuy Formula 3
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    Aug 26, 2004
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    Impressive and I assume expensive! Were you able to remove the cap without removing anything else, like the throttle linkage. It looks like there isn't room to get it out once it's loose.

    Since I didn't get the cap off on the first try and I'm thinking the mechanical advance might be the problem I started it up and it was barely idling, chugging along almost stalling. I rotated the distributor counter clockwise and as I did it started running better and better. I'm pretty confident now that the problem is in the distributor advance mechanism.
     
  24. Highmiler

    Highmiler Formula Junior

    Dec 8, 2010
    414
    Missouri
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    Greg
    I do not remember having to remove anything to get the cap off. I do remember it being a finger tips, screw driver and yoga exercise from the right side of the car.
    Greg
     
  25. kaiser

    kaiser Karting

    Dec 17, 2011
    73
    johannesburg
    I'm just wondering if it could have something to do with the fuel fill.
    I once had a tankful of fuel from the bottom of the petrol tank when I filled my Range rover, and I could drive 500 meters, then the filter would block. Blow back in the fuel line would get me another 500 meter or so.
    Eventually we drained all the fuel. Nothing to be seen. Left it overnight, and there was a layer of black particles in the drum at the bottom the next morning, and quite a lot. I assume rust. It had blocked the in-tank filter so the pump could not suck petrol to the main filter.

    It is possible that you have got water/rust in the tank, and that it mainly affects the side with the fuel filler. If it is rust, it might settle closest to the filling point.
     

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