Ryanater

I replaced the crankshaft sensor. And that's exactly what I thought... No kidding it's soaked with oil! It's in the timing cover!

Anyway it didn't fix the problem.

So here is where I am.
1) New distributor (which obviously includes the camshaft sensor)
2) New crankshaft position sensor
3) Still throwing the crankshaft to camshaft position correlation fault. I can clear the code and it will come back within 5 seconds of the engine being fired up

Any thoughts? I am thinking that they didn't check the timing correctly. I have a hard time believing that I installed the new distributor and got the timing within range just by guessing.

Anything else it could be?

Ryanater

Oh I forgot to mention that the engine seems to run much better now that I replaced my crankshaft sensor. It ran exactly the same or even a little worse right after I replaced it and now it appears to be getting better over the weekend. It might just be in my head though.

in2pro

When I had that error show up on my 97 5.7, it was caused by a burned wire harness going to the crank position sensor, check the wire harness running along the top of the passenger side valve cover, mine had fallen and was contacting the exhaust manifold, it burned through the loom and was melting the wires together....
I was able to salvage the wires before it got to bad, and replaced the loom and wrapped it in high temp tape I got from Summit racing's site...
Problem solved

Ryanater

Sure enough.... I spent the time moving the distributor, clearing the code, and starting it back up to see if the code came back. I repeated this until I got the code to go away.

So it turns out it was the timing all along. I don't appreciate the shop not doing what I asked them to do. But I guess there isn't a lot I can about it. The thing that really irritates me is that they specifically told me that my timing was "within spec".

in2pro

Sounds like you have it resolved
I found this, it may be a little late but it could help someone else along with all of your helpful troubleshooting and thought process..


Service Information
1997 Chevrolet Tahoe - 2WD | Chevy Pickup, GMC Pickup, Suburban, Tahoe, Yukon (VIN C/K) Service Manual | Document ID: 158167
--------------------------------------------------------------------------------

Setting Timing
Camshaft Retard Offset Test
The ignition timing cannot be adjusted. The distributor may need adjusting to prevent crossfire. To insure proper alignment of the distributor, perform the following:

With the ignition OFF, install a scan tool to the DLC.
Start the engine and bring to normal operating temperature.
Important: Cam Retard Offset reading will not be accurate below 1000 RPM

Increase engine speed to 1000 RPM.
Monitor the Cam Retard Offset.
If the Cam Retard indicates a value of 0° ± 2°, the distributor is properly adjusted.
If the Cam Retard does not indicate 0° ± 2°, the distributor must be adjusted.
Adjusting Camshaft Retard Offset




With the engine OFF, slightly loosen the distributor hold down bolt.
Important: Cam Retard Offset reading will not be accurate below 1000 RPM

Start the engine and raise engine speed to 1000 RPM.
Using a scan tool monitor Cam Retard Offset.
Rotate the distributor as follows:
4.1. To compensate for a negative reading, rotate the distributor in the counterclockwise direction.

4.2. To compensate for a positive reading, rotate the distributor in the clockwise direction.

Repeat step 4 until 0° ±2° is obtained.
Turn the ignition OFF.
Tighten the distributor hold-down bolt to 3N·m(25 lb. ft.).
Start the engine, raise engine speed to 1000 RPM and recheck Camshaft Retard Offset.

Ryanater

So now the P0121 (throttle position sensor) code is showing up again. The other codes are taken care of.

I thought this one would be an easy fix by replacing thethrottle position sensor. I replaced the sensor and the code will come back intermittently. It seems like it shows up every 100 miles or so.

The engine isn’t stalling out nearly as much but it still pings really bad upon acceleration.

I have heard that P0121 could possibly be cured by cleaning my throttle body really well. Anyone have any suggestions?

Ben Raines

It's really a distributor cap and rotor