QuestionWent for a weekend of racing and had these problems..
Took the car off the trailer and ran it for about 10 minutes at idle, turned it off and about 45 minutes later tried to start it up for a practice session and it would not start. Checked plugs/coil finally got it to start up after cleaning the ends of the spark plugs. Missed the practice session.
Later for the Qualifying session got the car out on the track and upon reaching speeds around 125-130mph the car started to sputter.
The next day for the race on the second lap the car started sputtering at 125-130mph and cut out. Pulled off the track and for an hour the driver tinkered looking for loose wires or anything as we were unable to get to him with tools, was unable to get the car started. Finally got to him pushed the car to where we could tow it back to the pits, he went to show us it wouldn't start and it started right up and drove back to the pits with no apparent problems, but it seems to be at high speeds.
The car has had problems at idle for some time, it tends to idle irradically.
We have had it at multiple shops with no luck finding the problem..
Matt
AnswerMatt,
What modifications have been done to the car? If you are running in an SCCA Improved Touring class or something similar then you probably have to run stock components.
It's hard to say with something like this, because I rarely(if ever) find myself at those speeds and there for rarely have problems at that RPM/Speed. But a sputtering is either lack of spark, lack of fuel, or a combination of the two.
I do know that the stock injectors MAX flow rate (CC/min) is rated for about 170hp. These engines make ~168 stock, so as you can see the injectors are almost maxed out in stock configuration. You add on 19 years of use, and they are probably pretty worn out. The biggest upgrade to get around this is to install Ford 19# (19 pound) injectors from a mustang. If your race class will allow mods like this. They connect to the wiring harness (the late-model ones may not) and fit just like factory replacement injectors. I would look at fuel as a possible problem. Second, look at the distributor cap and rotor. They wear pretty quickly, and if you notice any black spots on the points, you should sand them down so it will make a better transfer of energy.
Replace the plugs, wires, coil, cap and rotor if necessary, they all get worn over 20 years of driving, and as soon as you start beating on the car on a racetrack... it's bound to show it's weakness(s).
Hope this helps,
Josh
