I changed the plugs and they were all white- sign of being too hot. I checked the gaps and that was good. I think this is from the KS being bad and throwing the engine into fail safe. Is there a way to lessen the effects of this? I changed to NGK plugs- should I just run premium gas? I have been just using regular. What oil selection should I use?

 

any way to prevent this?

 

This maybe an ignorant question, but what's a "KS"?

 

KS = Knock sensor

 

If it's running in fail safe wouldn't that be on the rich side? I thought too hot would indicate a lean condition. What kind of MPG are you getting?

 

knock sensors on obd1 cars are a last resort for safety. If the KS was tripping a code or malfunctioning, you'd definitely be in safe mode, running piggishly rich and might have revs limited.

Were your plugs just white, or were they covered in white specs? There's a difference. White specs are indicative of detonation (which you could probably hear too), but white plugs are fine.

if it happens again you may need to run the next grade higher octane gas.

 

just chalkish white... Haynes says that means "running hot" I don't hear any pinging or detonation but it's throwing the KS code and prob in fail-safe I get 16 or 17 on the highway (should get 19) with 30k+ on this rebuilt engine... she runs pretty smooth... at idle the gear shift bobbles only lightly.
Would higher octane help with MPG and limit the fail safe effects?

 

have you pulled the new plugs to check their condition?

try that and compare. perhaps you were running too cold of a plug before?

 

just put the new ones in-- Everyone says the NGKs are the way to go- I was running Champion.

 

It wouldn't hurt to try a colder plug... I have a part # in my sig.

 

HMMM, I always thought a white plug was a good thing, none of the cylinders were burning oil..I have seen lots of white colorish plugs over the years