1991 Ferrari testarossa engine power problem

art20c · 08-30-2004, 08:01 AM

Hi
I have 2 problems with my tr
1. Unstable idle, goes up and down after engine was reved sometimes even stalls.
2. After 4000 or 4500 rpm engine looses the power feels like someone holding the car, but if I rev the engine while idling everything sounds and feels ok. I changed spark plugs, same result.
Please help

senna21 · 08-31-2004, 12:59 PM

Sounds like you might just need a tune up. With modern cars that means plugs, wires, distributor cap (if applicable), and distributor rotor (if applicable). Also your air cleaner. Very important on a heavy breather like a TR. The resistance in your wires, cap, and rotor(s) can degrade over time and with use. I would recommend changing these items on a yearly basis if the car is a daily driver and probably every 12,000 miles if it isn’t. Basically every fourth oil change.

It sounds like you’re having problems making power under load. First step is to make sure your car is in good operating order. That means a tune up. Then if that doesn’t clear it up we’ll have you take a look at the a) Oxygen (O2) sensor and b) fuel injectors. I’m guessing you’re not producing enough spark. How did the plugs you pulled look? Were they black or kind of brownish grey? Were all the plugs the same? If not which ones were different? Was one bank of cylinders different than the others?

carguy · 10-10-2004, 05:15 AM

A tune up is probably required. The usual reason for rpm's swinging up and down is that the engine in "unbalanced". That is the air/fuel mixture is not in balance between the cylinder banks. The TR engine is kinda funky where there is one ignition ECU for the entire engine, but two seperate fuel ECU's for each cylinder bank. So the engine is like to 6 cylinder engines running seperately with a common crankshaft. So in effect if one cylinder bank is running properly and the other is not, the poor running side will drag down the good running side, etc. Like Senna21 says, if all else is in good shape...you should take the car to a service shop for a tune up.

08-30-2004, 08:01 AM	#1
art20c Join Date: Nov 2002 Ferrari Life Posts: 3	1991 Ferrari testarossa engine power problem Hi I have 2 problems with my tr 1. Unstable idle, goes up and down after engine was reved sometimes even stalls. 2. After 4000 or 4500 rpm engine looses the power feels like someone holding the car, but if I rev the engine while idling everything sounds and feels ok. I changed spark plugs, same result. Please help

08-31-2004, 12:59 PM	#2
senna21 Join Date: May 2004 Location: Los Angeles, CA Ferrari Life Posts: 476	Sounds like you might just need a tune up. With modern cars that means plugs, wires, distributor cap (if applicable), and distributor rotor (if applicable). Also your air cleaner. Very important on a heavy breather like a TR. The resistance in your wires, cap, and rotor(s) can degrade over time and with use. I would recommend changing these items on a yearly basis if the car is a daily driver and probably every 12,000 miles if it isn’t. Basically every fourth oil change. It sounds like you’re having problems making power under load. First step is to make sure your car is in good operating order. That means a tune up. Then if that doesn’t clear it up we’ll have you take a look at the a) Oxygen (O2) sensor and b) fuel injectors. I’m guessing you’re not producing enough spark. How did the plugs you pulled look? Were they black or kind of brownish grey? Were all the plugs the same? If not which ones were different? Was one bank of cylinders different than the others? Charles Wells (aka senna21)

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10-10-2004, 05:15 AM	#3
carguy Owner Join Date: Dec 2003 Location: Michigan Ferrari Life Posts: 303	A tune up is probably required. The usual reason for rpm's swinging up and down is that the engine in "unbalanced". That is the air/fuel mixture is not in balance between the cylinder banks. The TR engine is kinda funky where there is one ignition ECU for the entire engine, but two seperate fuel ECU's for each cylinder bank. So the engine is like to 6 cylinder engines running seperately with a common crankshaft. So in effect if one cylinder bank is running properly and the other is not, the poor running side will drag down the good running side, etc. Like Senna21 says, if all else is in good shape...you should take the car to a service shop for a tune up.