News

348 cutting back why?

Discussion in 'Technical Q&A' started by Juan-Manuel Fantango, Mar 20, 2004.

  1. Juan-Manuel Fantango

    Rossa Subscribed

    Jan 18, 2004
    7,640
    Full Name:
    Juan
    at 4-5Krpms, my new to me car is begging to cut back and die...just loses power, sputters, backfires, then when I lower the rpms, it goes again. This car has race exhaust, and is a challege car with a fairly new engine. I noticed this at much higher rpms earlier, and was told it was the upgraded chip acting as a rev limiter once you got above 8600rpms. What gives? bad fuel? I noticed this happend after I fueled the tank. Also, I noticed that when I removed the tank cap, air rushed out. Air flow meter? Fouled plugs? Fuel pump? Dirtly filter? As you can see, I have no clue so your suggestions will be appreciated.
     
  2. vincent355

    vincent355 F1 Veteran
    Rossa Subscribed

    Apr 8, 2003
    5,700
    Wine Country
    Full Name:
    Vincent
    i am not sure why this is happening. But air rushing out of the gas tank is normal for sure.

    Vincent.
     
  3. ernie

    ernie Two Time F1 World Champ
    Lifetime Rossa Owner

    Nov 19, 2001
    22,022
    The Brickyard
    Full Name:
    The Bad Guy
    Have you checked your plug wires? That could give you the misfire at certain rpms. I had a similar misfire on my car. It would idle just fine, but soon as it got to about 3,000 rpm it would sputter and backfire all the way to about 4,800 rpm, then at around 5,000 rpm it was okay up to about 6,800 rpm. Turned out to be the number 2 plug wire was bad. You could see were it had burned through. I would check your wires first. Also when was the last time your fuel filters were changed? One of them could be clogged.
     
  4. fatbillybob

    fatbillybob F1 World Champ
    Consultant Owner

    Aug 10, 2002
    19,018
    socal
    You can guess at your problem but for abotu 100 bucks or less you can buy a cheasy scope meter to test your system and see where you problem is or at least narrow down your search. OTOH you could guess at each spark plug wire then the ingightors, then the coil pak, then the fuel filter, then the fuel pumps, then the pump relays, then the exhaust ecu thermocouple .....
     
  5. ernie

    ernie Two Time F1 World Champ
    Lifetime Rossa Owner

    Nov 19, 2001
    22,022
    The Brickyard
    Full Name:
    The Bad Guy
    LOL Billybob you big goof.
     
  6. Juan-Manuel Fantango

    Rossa Subscribed

    Jan 18, 2004
    7,640
    Full Name:
    Juan
    That's what I like about this group, whit and sense of humor. I found a station that sells 100 oct and put in 1/2 tank, and that seemed to solve the problem. Bad gas that was listed as 93.
     

Share This Page