Mazda B2600i pinging

[snoboy]

I have a 1992 Mazda B2600i truck with a Japser engine. The engine has apx. 8500 miles on it now but the injectors are original w/ 190,000 miles on them. The truck exibits a light ping on acceleration and when pulling long freeway grades. I put 89 mid grade in and it seem to help reduce the pinging but its not gone. Timing is @ 5 deg. advance set w/ vac line plugged and idle set per spec. I use FP every tank. What should I check? I think truck has a knock sensor. Plugs, wires, fuel filter, even the distributor are all new. All basic stuff is in order. Is it time for new injectors? Should I just step up to premium fuel. It seems like this would be a banaid fix for something else. The truck should operate on regular. Thanks
snoboy

 

[ediamiam]

pinging has been covered previously - search for this

Pinging in *stock* 01 Integra GSR - Engineers wanted

 

[snoboy]

Already did that.

 

[MONKEYMAN]

I had the same truck. I had to use Premium. Had to rebuild the head. Still had to use premium. Sorry, I cannot offer help. On a side note, the only vehicle I purchased new was a 94 Mazda B2300 (Ranger/Ford). I had to use Premium when new to keep it from knocking.

 

[snoboy]

I'm with ya there bro. I really dont think that any thing is wrong with the engine. I was afraid you'd tell me to run premium. But I think your right. Thanks

 

[mechtech]

The heads/deck have probably been shaved to true them up.
Higher compression is the result.
More octane is in your future.

 

[kcryan]

try not using FP for a few tanks.

 

[ediamiam]

Guess you don't have an EGR. Have you tried retarding the timing, although that would probably affect performance.

 

[audi_guy]

I had the same problem with my 93 B2600i. In my case pinging was caused by carbon deposits on the pistons. I could run Texaco Premium for a couple tank fulls and the carbon would be gone and the pinging would stop. I'd go back to using regular gas until the pinging started again then I'd do the Texaco Premium thing again. I tried using various fuel system cleaners to solve the problem but nothing worked. At 182K miles the cylinder head cracked at a coolant passage. The head was replaced. 60k mile later I'm running carbon deposits and ping free. I maybe wrong but I attribute my pinging problem to a defective head.

 

[jamesn]

i have ran jasper engines in 2 vehicles. a ford f150 -300 straight six- and a toyota forklift -20r- jasper shaved the beejesus out of the ford head.
the cranking compression was 15lbs higher than it should have been according to the ford garage.the guy i eventually sold it to tore it down and put a thick fel pro head gasket in it.