knock sensor? ESC??

[Steve GMC]

HELPPPPP our truck jsut started acting really random. its running like crap right now. i looked in the hanes manual and think it might either be the ESC or the knock sensor. when the truck is in nuetral it runs fine or at idle fine but if its goin up a hill it knocks like crazy. i looked for the esc but couldnt find it on the truck . or the knock sensor.do any of u guys know where the esc or knock is located? the truck is an 1986 chevy k30.




Thanks guys

Steve

 

[73k5blazer]

Knock sensor is usally located on the lower rear driver side of the block, just above the oil pan mounting surface. Could also be passenger side.
Has a goofy white/black plastic connector on it, not like a weatherpack or anything.

You can also bypass you ESC by disconnecting the 4 pin weather pak connector on the distributor and jumping pins A & C (On the distributor side).
Non-California trucks not included, they have their own rules, which I don't have.

ESC just retards timing when it detects knock, by bypassing it, you can elminate the sensor and computer as a source or trouble.

 

[Steve GMC]

so a knock sensor jsut detects a knock and sends that so the esc which slows the engine. so the knock can come from anything, rod, crank, valves

 

[73k5blazer]

It's on the lower part of the block, it's calibrated to detect spark knock.
It doesn't slow the engine, it retards the timing in an effort to get rid of the knock.

BTW, The ESC computer is located behind the glove box.

 

[Steve GMC]

o ok so theres something affecting the spark. from what ive read it says the fuel is detonating other than cartching on fire. so waht would cause this?

 

[73k5blazer]

Too much fuel (to rich), or too much ignition timing. The ESC equipped vehicles were timed a little more advanced than the older ones, they are counting on the ESC system to prevent knock by retarding timing when it detects knock.
You might throw a timing light on it and see if it's timed right to begin with. What it should be set at should be on the sticker by the hood latch, if you have the original front clip.

What is the engine doing exactly?

 

[Steve GMC]

at idle in nuetral the engine is skipping and rough, then when shifted into drive it strains and shakes very violently. going down the road at low rpms it is not bad but when you really get on the gas it pings bad. the engine seems to have no power anymore either. hope that helps

 

[broncoman6524]

your timing is too far advanced, or you could be 180 out...

 

[Steve GMC]

timing is fine, i just checked it this morning. but the #6 spark plug did seem to have oil on it

 

[dyeager535]

That year/application, you may not even have ESC. My buddies '83 C30 certainly did not.

 

[Steve GMC]

o man, that was another thing i was thinking