81 Mondial Engine Sensors | FerrariChat

81 Mondial Engine Sensors

Discussion in 'Mondial' started by ed_and_tonny, Nov 21, 2006.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. ed_and_tonny

    ed_and_tonny Karting

    Aug 4, 2006
    94
    Pawleys Island, SC
    Full Name:
    Ed Quillian
    Hi, I'm looking at an 81 Mondial as potential good project car. The current owner reports the car is running very rich. On my past 87 Maserati spyder I had a similar problem that was resolved by replacing a bad water temp sensor and the air intake temp sensor. Those 2 sensons in particular were critical to the ECU in determing the fuel mixture due to operating and ambiant air temps. Does anyone know if the engines in the Mondial of this vintage used a similar setup?
    thanks
    ed
    p.s. - any other "look for" advice would be appreciated as well.
     
  2. rolindsay

    rolindsay Formula 3

    Jul 14, 2006
    1,022
    Houston, TX
    Full Name:
    Rick Lindsay
    My '83 Euro Mondial QV had NO sensors. It was straight K-Jetronic. If the US cars had a lamda circuit, it could be bad. If not, think about some PO dinking around in the air flow/fuel distributor. I had a BMW 2002tii that someone had tweaked all the way to the rich end of the adjustment. That sucker would foul a set of plugs in 5 minutes! I guess some people just believe that "...if a little rich makes a little more power, a lot rich must make a lot more power." :-\

    rick
     
  3. ed_and_tonny

    ed_and_tonny Karting

    Aug 4, 2006
    94
    Pawleys Island, SC
    Full Name:
    Ed Quillian
    Thanks - it is a Euro model
     
  4. Birdman

    Birdman F1 Veteran

    Jun 20, 2003
    6,689
    North shore, MA
    Full Name:
    THE Birdman
    Lambda on the kjet didn't get used (at least in the U.S.) until 1984. On an '81 it's a simple old school CIS and the mixture is quite easy to adjust.

    Birdman
     
  5. dell550

    dell550 Karting

    Aug 24, 2005
    209
    London
    Full Name:
    george c
    Your car uses the original Bosche K-Jetronic constant injection system but it is wrong to say it has no sensors-there is a coolant temperature sensor via which the cold star injector is triggered but this is unlikely to the fault with your car as it would not run and flood the plugs out badly.
    More likely to be your problem is the warm up regulator-an oblong unit with 2 fuel pipes going to it from the metering head and at least one vacuum pipe.This unit manages the control pressure above the metering piston and damps its movement to prevent surges in fuel delivey and ensure a nice controlled fuel delivery curve. This system is relatively easy to test if you have the correct fittings and pressure gauge kit--too high a control pressure results in a slow fuel response and lack of engine response--too low will give fluctuating CO readings hunting engine rps and rich mixture Also dont forget that K-Jet injectors are a mechanical valve and need regular testing to ensure correct operation. we flow test K-jet injectors every 2 years or 10000 miles on our clients cars and also check for correct breaking open pressures as well as no dripping and spitting. All these tests can be carried out by a competent workshop in half a day or so BUT and its a big BUT you should have the engine checked over mechanically first.
    The reasons for this are two-fold ; first of all the K-Jetronic system is reliant on the engine being able to pull the correct amount of air through the inlet system to move the air flow sensor plate smoothly and sufficiently to inject the required amounts of fuel-if there is an air leak allowing unmetered in to the engine or if the valve timing is out causing a higher inlet pulse than standard will all effect the performance of the system--tight valves will affect the engines ability to create vaccum and will have a detrimental effect on how the K-Jet responds-second of all your problem could be as simple as a duff plug or ht lead and nothing to do with the K-Jetronic !!!!
     
  6. dsd

    dsd F1 Rookie
    Owner Silver Subscribed

    Nov 19, 2006
    4,271
    Northern Virginia

Share This Page