TR warmup/run problems. HELP!! | FerrariChat

TR warmup/run problems. HELP!!

Discussion in 'Technical Q&A' started by APA#1, May 26, 2004.

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  1. APA#1

    APA#1 Formula 3

    Nov 5, 2003
    1,311
    Central Florida
    Hi All, maybe you can help. Have an 86 US TR. When I start the car ice cold it starts and runs fine though does smell rich, but after a warm start (about 1 hour cool down) it belches black smoke, runs like crap and stalls.

    Last night it was pumping black smoke pretty good, Once it is up to 100% op temp everything is fine. This only happens after it's been parked a short time after running.

    Before I take it in to my mechanic just wondered if any of you had any thoughts. I do realize it's running rich when this happens and thought it might be a sensor. Thanks All
     
  2. MS250

    MS250 Two Time F1 World Champ
    Lifetime Rossa

    Dec 10, 2003
    26,654
    Full Name:
    Avvocato
    Hi,
    My 86TR did the similar many years ago. Its carbon build up in your system. When the car is ice cold (weeks of sitting) I start warm up engine for 3 minutes/when temp gauge moves, and put her in gear and keep it in 1st for a few blocks to warm up the gear box,rear end and tranny. Once temps up to normal I go driving. Sounds like she needs her legs stretched for a nice long hwy drive at 70mph in 4th with a higher rev to blow out the carbon. Worked for me, and never done it since.Though, you know the car better....do you do alot of city driving? Long warm ups? Low rpms when you shift gears?
     
  3. henryk

    henryk Formula Junior

    Dec 9, 2003
    479
    Door County, WI
    It sounds to me, like you have a problem with either the thermotime switch, or one/or both of the cold start injectors. This cold start system works when cold........and you seem to have no problem. But, it is supposed to run for only a few seconds........controlled by the thermotime switch, which turns the injectors off.

    It would seem that the thermotime switch is not closing at the proper temperature, allowing the start injectors to run longer........reason for black smoke. By the time the temp reaches normal, the thermotime switch closes.......thus it runs well when fully warm.
     
  4. APA#1

    APA#1 Formula 3

    Nov 5, 2003
    1,311
    Central Florida
    Thanks for the replies. I do let it warm up for 3-5 minutes prior to driving and do run it reasonable until the temps come up. This is a warm start problem more so. At temp the car runs great. I thought of the cold start valves too, dumping too much fuel into the engine. Is there a way to test the cold start valves ot the coupler? I do get some idle drop, like a burp when taking it out of gear coming to a stop, drops to 500 or so and immediately back up.
     
  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,932
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Craig -- You could have more than 1 problem. Although there may be other problems that cause it, one thing to check for the "drooping idle at decelleration but then recovers" is the throttle microswitch -- see:

    http://ferrarichat.com/forum/showthread.php?t=13067&highlight=microswitch

    With regard to your bad warm restart (yet good warm running) -- it's perplexing because on a KE-Jetronic TR, the major components involved in each mode are the same. The only difference that I'm aware of is that during a warm restart the injection ECU gives a slightly different current to the EM actuator on the fuel distributors to enrichen the mixture for a brief time (and that time depending on the temp thermistor resistance I believe).

    Are you able to tell when you have the over-rich problem if it's both banks or just 1 bank? (If you have a stock exhaust I believe they are co-mingled so both sides would smoke for a 1 bank problem, but if you have a Tubi then the tips are bank related so that could give a clue)

    During good warm running idle have you tried putting a voltmeter on the O2 sensor output wire from each bank? They should be behaving similarly and each banging around between 0.1 to 0.9V if it's really running closed-loop. If one or both are just "stuck" on a single voltage value this would indicate some definite unhealth.
     
  6. APA#1

    APA#1 Formula 3

    Nov 5, 2003
    1,311
    Central Florida
    Hi Steve, thanks for the reply. The overrich is coming out of both banks and is pretty heavy until full warm up. This only happened recently. I was running the car moderately hard, parked it for an hour or so and it ran badly. I believe the cold start valves are dumping fuel. The other day i took it out and it was overloading pretty good. The check slow downs even blinked (not good). Both of the conditions appeared at the same time
     

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