Ping during acceleration
 

I've had two co workers more versed in older trucks than myself confirm that during acceleration, my truck is pinging. Seems to happen worse in 3rd-4th gears with torque converter applied. I just ran a top end intake cleaner through the brake booster vac. line and added fuel injector cleaner with ~15 gallons of Chevron 87 octane fuel. No improvement yet but hopefully it will get better. In the meantime, what else could cause this to happen?

Check your timing 1st. if within spec, I would run 1/2 a bottle of sea foam thru the vacuum line

yeah, pinging would cause me to look at the timing first thing.

Ok I checked a couple things. Base timing is 10* BTDC with SPOUT disconnected, exactly where it should be. Checked manifold vacuum at idle, I'm getting 19-20 in Hg.


History: Motorcraft copper plugs, ACCEL coil, wires, cap and rotor 1 year ago
Fuel filter sometime in 2015
Intake manifold, gaskets and injector seals replaced about 2 years ago

Ensure that the wires for 7 and 8 are well separated, check codes and fuel pressure.

I've had a good separator kit installed for a few years, #7 and #8 are well away from each other. I've run KOEO and KOER tests and have no codes at all.

If the timing is ok then look for things that can cause a lean condition under load. Look fo vacuum leaks, especially on the PVC and EGR systems. I would check the fuel pressure and make sure the cooling system is up to snuff.

I will check fuel pressure tomorrow but it really doesn't run like it's starving for fuel. The truck has great power. Not overheating, low 200's most of the time.

You could have a dirty or partially clogged fuel injector or maybe there is a global lean condition, a spark plug reading would show that.. a single white plug would indicate a dirty injector, all plugs white would indicate a global problem.
If you have a global problem then something is making the computer think the engine is running rich and it is leaning it out excessively trying to compensate, in my experience that could be because of a leak in the theremactor(air injection) system. A common problem with that system is with the crossover tube and check valve at the back of the motor, these parts can crack and corrode leading to what often sounds like an engine tick or exhaust leak and that results in the engine running lean all the time.

How do you tell on these OBD1 vehicles whether the computer is going rich/lean?

What does it do if you hammer the skinny pedal, does it rev freely or fall on its face with RPMs? Thinking plugged Cadillac converter with this question but it could very well be a ignition timing issue.

If I stab/floor the throttle it will rev as high as commanded. Does not ping when stationary, but driving down the road with load on the engine, yes. Anywhere from 1/4 to 1/3 throttle it can start but will get worse with more throttle applied.

You have to install a wideband O2 sensor.. or read the plugs.

Update: tried some 91 octane fuel from Chevron, did a series of hard accelerations near the shop. It maybe pinged two or three times that I could actually hear, nowhere near as bad as before. Changing the fuel filter today and will take a pressure reading also.

My truck pinged due to a clogged up water jacket. Unlikely if the coolant has been taken care of though.