TBI92Camaro

OK, so here's the deal. 89 RS 305 TBI, 5 speed. Pretty much bone stock.

Car used to run like TOTAL crap. Heres what it would do...

You'd nail the gas and it would "studder" all through the RPM range. Felt WAYYYY down on power. I mean WAY, like it woulda had a hard time beating my 4 banger Mustang. Plain horrible. ALWAYS ran 87 octane gas regligiously since it was a beater car. Every so often it would run clean but plenty of times, more than I can count, it would fall on its face HARD the whole RPM band

Well, couple weeks ago, I took it to the gas station and said "hell with it" and put some 92 in it. Ran like crap for a lil bit but then started clearing up. Well, been running 92/93 octane religiously now. It runs liek crap on its first 5-10 minutes or so AKA till it warms up THEN runs fine. pulls clean (as clean as a 305 TBI can LOL) all the way to shift points. Itll run like crap once in a blue moon (1 outta 8-15 WOT pulls)

So I went to Autozone for the codes to get pulled. Pulled 2 TPS codes (IIRC) but the main one that caught my eye was the Knock sensor code.....

QUESTION: Did 305 TBI's come with knock sensors??? I swore they didnt but if they do, where exactly is it located? Would a bad one of these make the car run like crap??? How can I be for sure its the Knock sensor???

ALSO....How do you check timing on these things???? Seriously, Id liek to see if perhaps my timing is too high, hence why it runs liek crap with low octane fuel.

Car has a new fuel filter, new plugs, Taylor 8.5MM wires, new dist. cap, rotor button, and an Open Element Air cleaner.

Car DOES have an exhaust leak somewhere by the manifolds but it ran like crap long before the leak.

I know with 200K+ miles, it isnt gonna be a monster but I still dont expect such poor performance from this thing.

Home Built

The knock sensor is on the passenger side down near the oil pan...
There is a tan wire with a black connector in it that you unplug then start the engine and check your timing then turn off the engine and plug it back in. Not sure what the setting is usually 0 or 4 btc. I think in the camaros it is on the passenger side of the fire wall. It has to be unpluged to set and check the timing, this wire takes the timing advance out of the loop of the computer.

Mylilbowtie

Stock timing is 0 but most advance the timing to 4-6 BTDC. You will need to un hook the est wire to get the timing adjusted right.

With a bad knock sensor the ecm can retard the timing a lot. The knock sensor is on the passenger side of the block. By the starter and the engine mount right above the oil pan. It is threaded into a coolant passage so be careful when you take it out. Coolant in the face isn't fun.

I would replace the knock sensor. Get the exhaust leak fixed (maybe a flange gasket or manifold gaskets). Then check the timing.

pizza_guy

Wait a minute guys...

He said it runs quite noticably better on the higher octane. That means his knock sensing setup is working just fine. That is why your car is super down on power, the ecm is pulling timing.

The fact that the higher octane helps means you have other issues. It might be your base timing is off, so check that first.

After that, there is a few things that'll cause detonation:

--Carbon-coated combution chambers. They increase compression and create hot spots.

--Running lean

--Plugs that are too hot

--Timing advance is off/ignition equipment problems.

I would start looking at these options. Your motor is knocking, fix this, and your ecm will stop pulling timing.