The Post Tuning Checklist
The most important things to check after a tuning appointment.
Oil Change Frequency
- Turbo - ~2000 miles (1000 miles if run harder)
- N/A, Supercharged, Nitrous - ~3000 miles
- Track cars: After every race!
Spark Plug Change Frequency
- N/A: approximately every 2000-5000 miles
- Supercharged, Nitrous: approximately every 2000 miles
- Turbo street car: approximately every 1-2000 miles
- Turbo race car: This depends largely on the type of gas, ignition system, engine management, etc. being used. The need to change plugs could range anywhere from every other pass to once every race weekend.
My car is smoking white smoke - Coolant
- Blown headgasket
- Dropped sleeves
- Coolant center section on GT turbo going bad
- Head lifting under load
My car is smoking blue smoke - Oil
- Turbo seals going bad
- Cracked rings/ringlands on pistons
- Leaking valvestem seals
- Cracked valve guide
- Failed PCV system pushing oil into intake manifold
- Oil leaking from seals or catch can could be leaking onto exhaust
My engine is overheating; possible reasons:
- Blown headgasket
- Head is lifting
- Lack of air flow to radiator
- Radiator cap not pressurizing system
- Radiator fan wired backwards
- Radiator fan not working
- Air in coolant system
- Thermostat stuck shut
- Blockage in coolant system
I am now having misfire issues, check the following things:
- Spark plugs may need to be replaced.
- Spark plug wire(s) may be loose.
- Cap and rotor need to be replaced.
- Aftermarket coil/ignition failing.
- OEM coil failing.
- Ignitor failure.
- Grounding issue.
- T1 cam trigger air gap too loose or too tight.
- A/F is too lean – check fuel pressure if this is the case.
- Timing way off as a result of belt slippage or changed distributor position (anything that affects base ignition timing).
I noticed the Air/Fuel on my wideband has changed since the tuning session.
It is possible that the fuel pressure has changed. Also, your wideband sensor could be bad. Bosch sensors, in particular, are prone to quicker failure under high backpressure, high heat situations or prolonged exposure to leaded race fuels. Lastly, what engine management are you using? It is possible that your engine management system is lacking proper air temperature correction.
I had my car tuned at X boost level, but it’s not reading that same boost level now.
If the car was tuned during the warmer months, it is common to experience boost creep in the colder temperatures. Boost creep can be severe enough to hit the boost cut. If your car is tuned in the colder temperatures, it is common for it to run less boost during the warmer season. Cars that run manual boost controllers are more prone to these issues than cars that run electronic boost controllers.
I had my car tuned and it ran great for X time period, but now I’m having problems.
First, what has changed on the car? Any changes made to the set up will affect how it runs and requires the car to be retuned. If there have not been any parts changed some possible problems could be a change in: fuel pressure, battery voltage, grounds, timing, loose wiring/sensors, or poor electrical connections.