Running issues with '88 Testarossa. | FerrariChat

Running issues with '88 Testarossa.

Discussion in 'Boxers/TR/M' started by uzz32soarer, Jan 2, 2008.

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  1. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
    3,088
    Melbourne, Australia
    Full Name:
    Robert Hayden
    I've had the old girl for just over a year now, and yesterday clocked over 10 000 kms. It's not been a bad year, with very few issues except for the plug / lead problem a few months back and a couple of loose connections here and there.

    A few issues still plauge her, which appears to be legacies left over from her UK days.

    I continuously blow the 15 amp fuse for the 'oil fans'. But I'm not sure what or where these fans are to start the check process.

    And even after all these kms, I still have this annoying surging / bunny hop issue in the 2500 - 3100 rpm range.

    When I first got her she was a pig to idle and wouldn't hold fifth gear below 130 km/ph. There is a guy here in Melbourne (FerrariFixer on FChat) who waved his magic wand over her and sorted those issues quick smart. There was a lot of imbalance in the two sides of the fuel system and also she had a vacuum imbalance. I was so pleased when I bought her home. One touch of the key and the idle is perfect, even after two weeks with no running. Best of all is the great drivability. Ican now hold fifth down as low as 40 km/ph and smoothly pull away. A different car, thanks to Phil.

    BUT............................

    The initial problem of this surging / hopping continues with no change.

    Symptoms:

    Driving along in any gear, but lets pick fourth and fifth. Fourth gear at 2500 rpm, is close to 80 km/ph which happens to be our speed limit for major arterial roads. Fifth gear places you at 103 km/ph, open highway speed with just the lightest throttle pressure. As the car gets to 2500 rpm it starts to surge slightly. If you hold the same throttle position or lightly accelerate the surging becomes totally violent and starts to throw the car around in a backwards / forwards motion putting untol stress on the driveline components.

    If you lift off and drop below the 2500 marker, it goes away nearly instantly. At this point you can accelerate hard and push straight through the 2500 - 3100 range without even noticing it. It ONLY happens at the very lightest throttle pressure.

    Strangely enough, it seems to do it more when the weather is cold, and less as the weather is really hot (ambient air temp 35 deg C or hotter).

    Last week we took the car out and did 500 kms over two days. The drive home on the second day was a nightmare. Trying to hold the car at 100 - 104 km/ph (legal limit) in fifth gear became impossible. I'm riding the 2500 rpm marker and had to 100% concentrate on the balance. 100 rpm over and the surging started. A 100 rpm less and I'm holding up the traffic. Many times I had to drop to fourth and then RPM was at 3200 and over the band where the issues are and drive for miles in fourth just to give myself a rest.

    The car runs like an absolute swiss watch, except for in this range. When I'm on the track or punting hard, there is no indication at all that the car has any issues. It's only at whisper light throttle levels.

    Phil has the mixtures perfect, so I'm sure it's not that. But there is something going on that is seriously impeding my enjoyment of the beast, and after a year of this I'm getting towards the end of the tether.

    Lately I've been experiencing the same problem for a brief flash around the 1800 - 2000 mark also. Especially in Third and Fourth gears.

    You know that horrid jerking feeling when the car is running out of petrol and bunnh hops back and forth a few times before it finally dies and rolls to a stop. Well that's the feeling!!

    As it's so specific to a rev range, I don't know what it could be. Fuel distribution heads don't seem to go out of calibration without affecting the entire rev range. Ditto for the two fuel ECU's.

    Any ideas??
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,039
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    What engine family (on the engine block at cyl #6) -- F113A, F113B, something else?
     
  3. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
    3,088
    Melbourne, Australia
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    Robert Hayden
    Hi Steve,

    F113 B - 14425
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,039
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Some things you might try (although I have a feeling this is going to be a difficult Gremlin :():

    1. Send me a PM with your email address, and I'll send you a copy of Diagnosis Sheet 6 for the TR KE-Jet Injection System and some instructions on how to make some of the more basic measurements.

    2. After you've got the engine warmed-up, try removing one of the fuel pump relays so that you are just running on a single bank and see if the problem is still there or not. Then replace that fuel pump relay and remove the other one and see if the problem is still there or not when running only on the other bank. When only running on one bank, you might need to give it a little throttle to keep it running at idle (and the power will be 1/2), but I think it would be a good clue if you could determine if the problem is really only occurring on one bank or if it occurs on both banks.

    If the problem is only occurring on one bank, the next steps would be things like measuring the current in the EHA coil of that bank and seeing if it's going wacky when the problem occurs and disabling the vacuum-controlled bypass valve to see if that eliminates the problem, but if you can get the information from steps 1 and 2 above it could help give direction.
     
  5. carguy

    carguy F1 Rookie

    Oct 30, 2002
    3,402
    Alabama (was Mich.)
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    Jeff
    Steve....could the throttle position microswitch have any bearing on this issue? It seems to happen at the initial throttle plate tip-in?
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,039
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    I'm not 100% sure if it could or not -- it's one of the things listed in the Diagnosis Sheet 6 tests (and reasonably easy to test), so it's something I'd test/confirm anyway just as part of some basic pre-tests on any sick KE-Jet TR. Same thing for the coolant temp thermister resistances and making sure that the +12V power is present and reliable to the injection ECUs. If the throttle microswitch is the issue, the way it would appear in the system would maybe be driving the EHA irratically -- so IMO that's maybe the "best" overall measurement to make on a F113B KE-Jet without Lambda to confirm/deny the health of the electical part of the F113B injection system -- i.e., some reasonable steady EHA current values that decrease with temp/time from cold start-up, steady lowish values during constant warm-running conditions, and the appropiate increase (richness) for WOT, sharp acceleration, etc. would say that the electrical side is doing what it should be.

    Frankly, I'm not as convinced that this couldn't possibly be a FD problem as Robert is, so, without any information at all yet, I'd say he'd almost be lucky if this was an electrical fault.
     
  7. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
    3,088
    Melbourne, Australia
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    Robert Hayden
    Steve and Jeff, I really wish you blokes were around the corner. We'd fix this old girl then have a good laugh over a beer or three..............

    [email protected] will find me.

    I'll try the fule pump off trial today, but I'm tipping that the car will take more throttle to drive with one bank out and probably won't play up. As Jeff say's, it only happens at the lightest throttle settings.

    Steve, what's this mean, "Frankly, I'm not as convinced that this couldn't possibly be a FD problem as Robert is" (FD, what's that - Fuel delivery?)
     
  8. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,039
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    FD = Fuel Distributor

    email sent -- give a shout if you need help or have a question; otherwise, will await your results for steps 1, 2, 3, 8, 9, and 11.
     
  9. regisgtb4

    regisgtb4 Formula Junior
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    Mar 20, 2007
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    tx
    Full Name:
    willis
    There are 2, get them from BMW ,6 series from the 80s are $120,these are the smooth controllers,routine maintenance to replace these on Redcars.
     
  10. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
    3,088
    Melbourne, Australia
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    Robert Hayden
    Well today was an interesting day. A mate has this great electronic gizmo and we fitted it up to the Testa then went out for a run. First tried it on the drivers side exhaust, so I have to imagine that is the left side of the engine the way the pipes cross over. Someone here might be able to confirm that.

    Instantly it was obvious that the car is WAY too lean. We took it out into the traffic and finally got it onto the freeway where I could maintain some even cruise to replicate this spasmodic jerking that it's been doing for over a year now.

    The car runs worst at 106km/ph in fifth. It's at around 2600 rpm here and it will just start jerking violently until it shakes the car apart or you power on and drive through it. Mixture was at 19.68 when it started jumping around. Stab the throttle and it went to 18.5 and the jerking goes away. Wide open throttle was 15.8, but generally it was between 18 and 21 all the time.

    We then stopped and changed over the lambda sensor to the other exhaust, which I presume is the drivers side of the engine. Even worse. 22's most of the time at 20.5 when the jerking started at 106 km/ph.

    No matter how hard I drove it, I couldn't get into the 14's. 15.7 was the lowest I saw and that was giving it hell in second gear. Idle mixtures seemd better at 15.8 or so, but as soon as I get moving it just isn't getting any fuel at all. Geez, no wonder I'm getting 25 mpg out of it.


    So, I've been told time and time again to get it on a dyno with an analyser up it's arse to see what's happening, so now I've gone one better and done some actual road miles. Nest thing I suppose is to try and tune some fuel into her??
     
  11. carguy

    carguy F1 Rookie

    Oct 30, 2002
    3,402
    Alabama (was Mich.)
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    Jeff
    It sounds like your on the right track Robert. For tuning my car, I finally had to "man up" and buy a 4-Gas Analyzer to sample the exhaust stream so I could adjust the fuel mixtures correctly. There is a thread or two on the procedure for adjusting the TR fuel mixtures...but I can't seem to find it. If someone else finds it - please post a link...
     
  12. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
    3,088
    Melbourne, Australia
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    Robert Hayden
    Even using a four way analyser, it's still best to tune the car for cruise and get the numbers as close to 14.7 as possible. The only way I can see to do this is either having a mobile four way gas unit so you can actually drive along on cruise at 60 mph and check the numbers. Even then you will have to stop and tweak, then run again, check the numbers, stop and tweak and so on. Only other option is tune it live on a dyno.

    Idle mixtures have some importance to get the car to idle right and warm up nicely, but it seems cruise mixtures are the most criticle. Problem with the KE system is there is bugger all to actually adjust>

    Steve M might have some clues or feedback on this.

    Did you buy a snap on 4 way or something similar Jeff?
     
  13. northern frog

    northern frog Karting

    Oct 26, 2007
    50
    Calgary Alberta Cana
    Do you have cats on your car?
     
  14. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,039
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #14 Steve Magnusson, Jun 1, 2008
    Last edited: Jun 1, 2008
    Your report that some enrichment does occur at WOT, or when stabbing the throttle, is a sign that the electrical part of your KE-Jet system is working (which might be a bad thing since an electrical problem could be easier to fix than a hydraulic problem).

    Were you able to confirm/deny any of the electrical tests that I emailed to you? You really don't want to do any mechanical tweaking until you are fairly sure that the electrical stuff is working IMO.
     
  15. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
    3,088
    Melbourne, Australia
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    Robert Hayden
    Steve I haven't done all the tests yet. Slack I know, but I was waiting till I could get some gas analysis done so I could report back in with a bit more info. Today I had a bit of a further tinker with the o2 sensor up its bum on both sides. Both fuel heads are lean as can be. Both around the same. 15.5 at idle, 19 at cruise, and off the scale 30+ on over run. For me it was interesting that no matter what I tried, both sides were bad. I was sort of hoping that one side had good mixtures and the other side was crook, would have made it easier to diagnose.

    I was always of the impression that the car had two fuel ECU's located in the upper rear quarter on the RHS. After today, it appears that these are the ignition ECU's and that there is only one fuel ECU mounted on the LHS upper quarter. I found this out by mistake. Laying alongside the radiator over flow bottle I found a small rubber tube which had vacuum on it. I followed it to the front of the inlet manifold on the LHS but it didn't go anywhere. Then I started looking around and I found an empty nipple where it appeared to go, on the single ECU on the LHS!

    From what I can see this must be the fuel ECU and it needs to monitor manifold vacuum, like a MAP sensor does, probably so it can alter mixtures. I stuck it back on, and even though the car idled a little better, my problem got worse and the car actually leaned out even more! It appears that it must have been removed at some time in the past to try and make the car actually get a bit richer. I actually took it back off again as at cruise the car actualy runs a little better with it off and sucking vacuum, rather than connected which just isn't right!

    From what I can see today the problem is causing issues to both banks. That sort of discounts individual components causing the issue. I have to look for components that will affect both units together. Temp sensor has to be the first thing to check, and maybe even the ECU itself. I can borrow an ECU from another car and try it to see if there is any improvement. Then I suppose the next thing is to run the full set of tests and see if I can pinpoint any further component failure.
     
  16. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
    3,088
    Melbourne, Australia
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    Robert Hayden
    #16 uzz32soarer, Jun 2, 2008
    Last edited: Jun 2, 2008
    Just to confirm. The 3mm allen key screws under the top cover of the KE units, purely adjust idle mixtures? Even with these now set slightly rich at idle, the car is still really lean at any throttle level. So the only thing I played with today was the idle mixtures and the big brass bypass air valve to set the idle speed and balance the two banks.

    There is no other mechanical adjustment to richen the mixtures on a KE Jet apart from idle mixtures, is that right?

    My car has no CATS and no O2 sensor in the exhaust. Is this normal for a UK spec KE Jetronic car? Does the fuel ECU simply hold a flat file? Having only basic information fed into it, like engine temp and throttle position, it has no ability to make changes to the fuel curve like it would if it was reading an o2 sensor.

    I expect that a car with CATS and an O2 sensor wired to the fuel ECU would be able to run an infinitely variable fuel curve dependant upon the input sources. Did any Testa's run 02 sensors?
     
  17. Tifoso1

    Tifoso1 F1 Rookie

    Nov 18, 2003
    2,598
    Pacific NW
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    Anthony C.
    I think you still have O2 sensors in front of the where the pre-cats are for US cars. Their functions are to monitor the engine exhaust and so the FI system can adjust the fuel mixture accordingly.
     
  18. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
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    #18 uzz32soarer, Jun 2, 2008
    Last edited by a moderator: Sep 7, 2017
    My car has no O2 sensors. The original exhaust would have looked like image number one below. Number 29 is listed as 'plug for CO intake'

    USA spec car with O2 sensors would look like image number two below. Obviously the USA cars have a different wiring loom and fuel ECU to take the extra inputs from the O2 sensors. Part number 1 shows the USA spec oxygen sensor.
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  19. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
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    #19 uzz32soarer, Jun 2, 2008
    Last edited by a moderator: Sep 7, 2017
  20. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
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    #20 uzz32soarer, Jun 2, 2008
    Last edited: Jun 2, 2008
    Disregard aspects of my first post today. I was right after all, there are two fuel ECU's as I just confirmed fromt the parts book. The single one on the LHS is the ignition module and it does have manifold vacuum going to it, Ferrari call it the 'ignition module depression hose'.

    Now, this hose is not attached on my car and obviously it should be, yet without it I actually do get the mixtures a little bit richer, not much, but a point or so.
     
  21. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    #21 Steve Magnusson, Jun 2, 2008
    Last edited: Jun 2, 2008
    It's more accurate to say that small adjustments of the mixture screw have a larger effect at idle because the slits in the FD aren't opened very much at idle (so a small adjustment of the slit opening is a bigger percentage change). At large airflow (i.e., large slit opening), these small adjustments are reduced to a very small percentage of the slit opening so not much effect on A/F ratio at large airflow.

    Correct

    Yes, this is correct for a F113B TR -- Your system operates similar to a K-Jet without Lambda system where the warm-up regulator has been replaced by the injection ECU and the EHA valve on the FD (to add enrichment when cold or when you blip the throttle).

    Yes, US, CH, and CAT versions. They've got the added smarts to dynamically vary the electrical signal going to the EHA valve to keep the average O2 sensor output a 0.5 volts during non-WOT warm-running.

    You've got the right thought that both banks going from good operation to bad at the same time implies that it's something common to each bank (if we can trust you that there was prior good operation ;)). Please advise if the electrical tests show something wrong.

    PS You shouldn't have that vacuum hose disconnected from the ignition ECU. This will cause the ignition timing to always be very significantly retarded. You won't be happy if you have to replace the ignition ECU -- it's hard to find and pricey.
     
  22. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
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    Nope you can't trust me on that at all. When I bought the car back in '06, it wouldn't hold 5th gear under 140 km/ph and when cold it hunted really badly, between 500 and 1500 rmp. Warming it up was terrinle, always thinking it had stalled and then it would rev up again, then die dow. Once running (or warm) it started and idled fine though.

    Then I had a local Ferrari Fixer tune it, and since then it's been great, idles perfectly from cold during warm up, and I can drive it at 60 km/ph in fifth if I want to. Totally different car. BUT!! It's always done this jerking at 2500 - 3200 rpm, and tuning it didn't get rid of that at all. It's taken till now to actually get some cruise readings to see what it's actually doing, and obviously it running way too lean. But on both bannks pretty evenly.

    So no, I can't attest to "prior good operation" but I remain hopeful that sometime soon I will actually get to experience the Testarossa goodness the way it is intended to be, right accross the rev range with no shortcommings.

    I'll start on all those electrical tests as soon as work loads allow, and lets see what is discovered.
     
  23. northern frog

    northern frog Karting

    Oct 26, 2007
    50
    Calgary Alberta Cana
    Ok . I am going to go out on a limb here. If your car has no cats, and no O2 sensor it is always working in open loop. I have no experience of fiddling with the Bosch K jetronic on my TR. but I did quite a bit of that with my porsche which is like one bank of the TR and I did run open loop for a while without any problems. I never could follow the instructions for proper checking of the system which I am sure Steve gave you, but you can do so useful tuning with a cheap 2 wire Bosch o2 sensor that you plug anywhere you can in your exhaust and a voltmeter and long lead wires. it will tell you if you are rich or lean, but not how rich, or how lean. In the Porsche the best I can do is rich sometimes, lean sometime. As you noticed there is not much you can do. But to check if your problem is really due to fuel mixture you can make sure the warm up regulator is always "cold" That will enrich your mixture, Beyond that the only other semi easy way to adjust the mixture with which I have any experience is to fool around with the counterweight in the air flow sensor. With lighter weight the lever moves more for the same air flow and gives you more fuel > richer!. Nasty but I like to fool around. Not sure I would do that with the TR! Hope this does not confuse you further
     
  24. uzz32soarer

    uzz32soarer F1 Rookie

    Sep 9, 2006
    3,088
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    Robert Hayden
    Hmmm.....the Ke Jetronic on my car has no warm up regulators either. I've tried to adjust the screws in the air flow sensor but cannot get enough adjustment to get the cruise mixtures even close to rich enough.

    Work is a b1tch this week, but as soon as I get a half day I'm going to do all of Steve's tests, starting with the temp sensor. Seems the only way to chase down the issue, now that I have confirmed that it is lean right accross the range.
     
  25. Sean F.

    Sean F. F1 Rookie

    Feb 4, 2003
    3,059
    Kansas
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    Sean F

    Don't know if someone mentioned this, but one of my old cars did this and it was a bad plug wire. Check your wires if you've not already done so.
     

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