Pings

[gmantob]

my 93 Ls 400 has 148000 on it had timeing belt replace full tune up plugs,wires ,cap rotor, kn air fliter,vales adjusted,, fuel filter,t body i cleaned with spray,. car runs great but when its cold hit the gas it great,but whe n its hot it pings and not great pick up i used hess 93,i put in lucas fuel inj cleaner,about 3 times . help no codes , i change the 02 sensors all 4. :(

[AussiLS400]

Try a different petrol station. The petrol you think is 93 might be tainted with low octane or other additions.

[mburnickas]

my 93 Ls 400 has 148000 on it had timeing belt replace full tune up plugs,wires ,cap rotor, kn air fliter,vales adjusted,, fuel filter,t body i cleaned with spray,. car runs great but when its cold hit the gas it great,but whe n its hot it pings and not great pick up i used hess 93,i put in lucas fuel inj cleaner,about 3 times . help no codes , i change the 02 sensors all 4. :(

Fp60 should get rid of the ping.

[lexusman400]

It could be a bad knock sensor, or bad gas, the Octane rating of gas is determined by the Research Octane number added to the Motor Octane number then divided by 2. If the research octane number is high (this is a theory test) then the Octane will rate high even though it is actually low. There is a 30 amp fuse under the hood, remove this fuse for 1 minute and then replace it and drive the car, stop and take off fast three times making it to high gear. This will reset the driving condition programmed into the car. This program determines the timing and injector sequences.

[Ross W.]

If all the other issues have been eliminated, that the others have offered, check that the thermostat is within spec. They usually go bad at around the mileage you've got, which is what happened to me. I finished the tune-up on my car and it still pinged a little, but after I replaced the thermostat, which my mechanic pointed out, no more ping. The engine was running 20 degrees cold, and it was unhappy in that condition. Two tankfuls with Lucas injector cleaner helped, which you've already done. After that I'd consider leaks or problems with the EGR system (it sometimes causes pinging on the back two cylinders, driver's side), and the fuel injector o-rings could be cracked, letting extra air in. The mass air-flow sensor could be sluggish too.

Hope this helps!

[jzz30]

engine temp sensor to the ecu may be faulty... but this may be a simple thing to check. you just need to measure resistance

[gmantob]

It could be a bad knock sensor, or bad gas, the Octane rating of gas is determined by the Research Octane number added to the Motor Octane number then divided by 2. If the research octane number is high (this is a theory test) then the Octane will rate high even though it is actually low. There is a 30 amp fuse under the hood, remove this fuse for 1 minute and then replace it and drive the car, stop and take off fast three times making it to high gear. This will reset the driving condition programmed into the car. This program determines the timing and injector sequences.

There is a 30 amp fuse under the hood where is this what is it called i saw a 30 amp fuse but it not a reg fuse it i a red box with a clear window on top that comes off is that it? i look like a fuseable link?