Jimmy pinging

[tstewart]

I have a 2001 Jimmy with 136K miles. I have owned it from new and it has been very well maintained. I have been experiencing pinging under hard acceleration. It only seems to occur after running for quit awhile and is not as prevalent when first getting to temperature. It otherwise runs and idles very well. The following items have recently been performed. Note, I have had no SES lights come on.

New injectors and air pump (installed by dealer)
New plugs (AC)
New rotor and cap
New ignition wires
New gas filter
New PCV
Cleaned flow sensor
Performed a water injection to de-carbonize the top end.

Any suggestions on what to check next.

Thanks in advance for the help.

[wolfox]

Run a bottle of SUV sized (20 Oz.) Techron through it. Wait until you are down to half a tank. Pull up to the fueling station, dump the bottle in and then fuel up. Run it until almost empty before refilling again. There is a lot of good stuff in Techron that may clear out the deposits that cause pinging on the very first dose. If you have to do a back to back dose, do so - but I would recommend changing your oil afterwards.

[tstewart]

Originally Posted by wolfox

Run a bottle of SUV sized (20 Oz.) Techron through it. Wait until you are down to half a tank. Pull up to the fueling station, dump the bottle in and then fuel up. Run it until almost empty before refilling again. There is a lot of good stuff in Techron that may clear out the deposits that cause pinging on the very first dose. If you have to do a back to back dose, do so - but I would recommend changing your oil afterwards.

I have been using a maintenence dose of Red Line Injector Cleaner / Lub in each tankful and before each oil change I do a full dose.

Is the Techron considered better than Red Line?

[wolfox]

Depends on what you mean by better. Techron in my '95 works. Cleans up carbon and other "hard" deposits in the combustion chamber which stops the knocks and marbles sound under the hood for at least 5-7k miles. Cleans injectors and valves safely too. Fuel quality is very poor where I am at and the truck rarely goes 6k miles between full tank "shock doses" of Techron 400miles before an oil change before the marbles under the hood sound comes back.

[blazee]

Techron is the only kind I use. It's the best kind that I know of. The formulation is extremely similar to the stuff that GM sells for twice the price. (The stuff the GM sells is also made by Chevron.)

[tstewart]

Originally Posted by wolfox

Depends on what you mean by better. Techron in my '95 works. Cleans up carbon and other "hard" deposits in the combustion chamber which stops the knocks and marbles sound under the hood for at least 5-7k miles. Cleans injectors and valves safely too. Fuel quality is very poor where I am at and the truck rarely goes 6k miles between full tank "shock doses" of Techron 400miles before an oil change before the marbles under the hood sound comes back.

Thanks, I will give it a try!