pinging

matumus

Registered User
Hello Everyone,
I have a 93 sc that i have rebuilt with a few mods. It has been running well up to a few months ago but lately I have developed a bad ping under boost and only under boost. Has anyone had anything like this or maybe could help I'd appreciate it.

Matumus - matumus@yahoo.com
 
Another word for pinging is detonation which can cause your head gasket to blow if left unchecked. Start by, staying out of boost, go to a higher octane fuel, put the factory MAF back on, Try to get codes scanned. If you have EGR, check to make sure the egr pipe & hose are intact. good luck
 
are you using 92 octane? do you get a CEL or anything? any other symptoms?



P.S. go to www.sccow.com and join!! (supercoupe club of washington) just make a post and introduce yourself etc etc

later! :)
 
My BIG guess!! Not enough fuel and your engine is leaning out under boost.

Either that or a timing issue (advanced too much), but the ECM should be handling that.

So not enough fuel could be:

Engine computer not able to compensate for increased intake air capacity. (Maybe the MAF is giving wrong information)

Fuel pump is unable to maintain flow when under WOT.

An injector is failing and only really shows up when under high stress.
 
1. Check fuel pressure and follow procedures

2. Check for any unmetered air; loose crankcase vent tube, busted vacuum lines, etc

3. Pull the EGR and clean or replace if you have one. Make sure the related components of the system are operating(transducer, switch)

4. If possible try higher octane fuel to see if that eliminates the ping. If it doesn't then there might be a starved inj and a cylinder balance test might isolate the cylinder.

Just a guess but have tried different gas stations? A newer station will have newer tanks with less contamiation getting in your tank. Just a guess. Good luck.
 
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