I've got an 89 5.0 that's basically bone stock. I've got a K&N and Flows and 108,000 miles on it. With the timing set at 12 deg. with 93 octane I'm getting detonation when I get on the gas. Anyone got any ideas on how to stop it?
check the operation of your egr valve. make sure the diaphram opens and closes. Remove and check for carbon build up inside the pipes and on the valve (anything that would ubstruct flow) Remove all carbon and free up flow. Does your car use oil? Does your car run cold? If your car runs cold or uses oil this will cool down the combustion temperater causing less of a burn in the air/fuel mixture. Those leaving carbon diposits on the top of the pistions and the combustion chamber. This carbon can cuase pre ignition and diesling on turn off. Also if gets worse could scratch and score cylinder walls. Also make sure your fuel and ignition systems are up to par.
Also always use the lowest grade gas possible that your car will handle. No use using premium when you dont need it. Many people think there car runs better or faster putting premium fuel in a stock car. Many dont know premium fuel actually has less energy. It burns slower and has a higher resistance to detination. Use the lowest possible octane your car will take with out detonation and youll be faster. (just a little .2 cents)
Pull the codes out of the computer and see if they give you a clue what's wrong. As rdgt says, it may be egr related. When that system malfunctions, often detonation is a result.
Is your K&N filter a conical that's in the engine compartment?
Dump the codes and see what the computer says is wrong…
Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.
Pinging or spark knock is not the same as detonation.
Pinging is preignition of the fuel air charge by some source of ignition other than the spark plug. The source of the ignition can be a hot spot in the combustion chamber such as carbon, a spark plug insulator, side electrode, or a sharp edge on a valve. It occurs before the spark plug can fire and while the piston is still on its upward movement towards TDC. That is the cause of the characteristic ping or ringing sound, much like shaking a coffee can full of BB’s.
Detonation is the uncontrolled explosion of the fuel air charge after the spark plug fires and starts to burn. In a properly running engine, the spark plug ignites the fuel air charge and it burns slowly and evenly across the combustion chamber, much like a fire as it burns its way across a grassy field. When detonation occurs, the ignited fuel air charge causes an increase in the combustion chamber pressure and temperature. The remaining fuel air charge that has not been burned self–ignites explosively causing tremendous heat and pressure. The source of secondary ignition can be the same as preignition, or can be simply due to the heat and pressure. Detonation is what damages engine parts because of the excessive heat and pressure.
Pinging can lead to detonation, and the results are the same: engine damage because of the excessive heat and pressure
Pinging is caused by a number of things:
1.) Hot spots in the combustion chamber such as carbon deposits from high mileage or excessive oil consumption.
2.) Wrong heat range on the plugs.
3.) Too much initial spark advance.
4.) Lean fuel mixture.
Lean fuel mixture breaks out into several sub categories:
A. Vacuum leaks
B. Air entering the intake without passing through the MAF
C. Failure of the MAF, BAP/MAP (Baro or Manifold Air Pressure, same sensor, different name), ACT (air charge temp), or ECT (engine coolant temp). These should set a code in the computer.
D. Leaking exhaust gases from EGR valve.
E. Clogged fuel injectors.
F. Fuel injector wiring problems causing injector not to deliver rated flow.
5.) Computer problems: (computer problems are not common like sensor problems)
A. ROM has bad data in fuel or timing table. This should also set a code in the computer.
B. Failure of one or more of the computer's driver transistors for the fuel injectors. No code set on this one.