'96 Blazer accelleration "ping"
 

new here and have not found much with the search on this problem..

I have an '96 Blazer 4.3L 4X4..under accelleration the engine "pings " (like pre-ignition ?? ) and just doesnt seem to have much/any power to it..

the engine has almost 103k on it..no codes come on the scanner..I've changed plugs and wires,tried different gas..Im thinkin' maybe the MAP sensor ?? But wouldnt that flip the service light on ??

anyone with any ideas for me to try or things to check would be greatly appreciated

RE: '96 Blazer accelleration "ping"
 

check your timing? (throwing things out there)

RE: '96 Blazer accelleration "ping"
 

by trying different gas, did you go up to a higher octane?

RE: '96 Blazer accelleration "ping"
 

yep..even tried adding various octane boosters

didnt know the timing could be advanced,the sticker under the hood says that ignition timing and idle speed are automatically controlled and not to attempt adjustment..

Ive been driving "beaters" for 20 years,so this '96 Blazer is my first "high tech" vehicle,so I really dont know much about all this computer controlled stuff. My wife drove it for 3-4 years.Shortly after she got it,it had the intake gasket replaced and really hasnt been the same since even though it was done at a dealer,so maybe the timing does need advanced a little. How do I do that ?

RE: '96 Blazer accelleration "ping"
 

The base timing should not be modified unless it is found to be off. I believe you have to disconnect a wire inside the passenger compartment inorder to check the base timing. Until you check the base timing, I would not move the distributor.

One thing that has been coming up more as of late is wear on the gear on the bottom of the distributor. If this wears enough, the commanded timing may be maxed out and still not be enough to work properly. I can check this with my scan tool, but most code readers cannot.

I would pop off the distributor and check the contacts inside. If anything has deposits on it, replace both the cap and rotor.

Good luck and keep us posted!

RE: '96 Blazer accelleration "ping"
 

Ive changed plugs,plug wires,dis. cap and rotor,air filter.. should add that its worse once the engine is warmed up,on a cold engine it does not do it


Ill have to see if I can figure/find out how to check the base timing...

I guess I need to find a service manual ,anyone know where I can get one ? Im talking about the shop service manual,not a Haynes or Chilton

RE: '96 Blazer accelleration "ping"
 

so far I havent got anywhere on this..thought maybe I had it worked out but today was a "pingin'" day

[:@]

RE: '96 Blazer accelleration "ping"
 

It is also possible that you have some carbon buildup on the inside of the cylinders that is creating hot spots.

Have you tried running either GM Top Engine clean or Seafoam through the intake?

RE: '96 Blazer accelleration "ping"
 

not yet,Ill pick up a can of Seafoam today and run it through over the weekend though

could be carbon,it has almost 103k on it and only pings when the engine gets hot (warmed up)


also swart, I was told the base timing isnt adjustable ?? that doesnt seem right to me,can you or anyone else verify that ??