My wife'* first car/truck is out of the garage after about 10 years and runs pretty good. It'* a bit rough so after a tune up I took a new code reader to it and wanted to see what I got back. OMG!!! I have the following codes:

14 - Coolant Sensor - Signal Voltage low or shorted

31 - CAM Sensor Circuit Problems, Park/Neutral Switch
32 - EVRV Error, EGR Valve Diagnostic Switch - closed on startup, MAP Sensor Signal - low voltage
33 - MAP High Voltage During Idle
34 - MAP Low Voltage During Ignition On

41 - CAM Sensor Failure, Cylinder Select Error, EST Circuit Open/Shorted, Ignition System Fault
43 - ESC - Circuit Problems, EST Low Voltage

51 - Computer Problem - Faulty, wrong or incorrectly installed PROM or ECM/PCM Failure
52 - Calibration Package Chip or ECM Fault or Oil Temperature Sensor Fault/Low Engine Temperature, Faulty or Missing PROM, ECM Problem, High Voltage
53 - System Voltage to High (>17.7 volts to ECM) or EGR System Fault or Alternator Voltage Not Normal or Vehicle Anti-Theft Fault
54 - Fuel Pump Circuit Fault or Mixture Control (M/C) Solenoid Fault or ECM Fault, Fuel Pump Relay
55 - ECM Fault or Oxygen Sensor Circuit Fault

I REPLACED:

EGR VALVE
PCV VALVE
MAP SENSOR
WIRES, etc.

I disconnected the battery after trying to clear the codes with my Innova 3140b and still could not clear them. At this point I think the ECM must be failing since there were multiple codes pointing to that and that could be causing everything else.

Anyone venture a guess or some guidance here? I have no clue what to do next other than the ECM and see what happens then...

The first thing I would do would be clear the codes and drive it for a week, and then recheck the codes. The 4.3 is a solid engine, but has some issues such as lower intake manifold gasket. Not sure all the damage that may of happened in 10 years of sitting, but change the oil, make sure the trans fluid is ok, clear the codes and drive it. check it all a week later. I suspect many of the errors will not come back.

i would find all big power and all the grounds and clean them, codes sound like the voltages are not right. thats the first thing i do on older vehicles, ive had some fall apart in my hands.

So here we are - getting better...

ECM replaced. Then the harness shorted. There was antifreeze in the harness which shorted at the connection to the ECM. Now I am left with one problem.

The engine is running real rough and almost no power and it feels and does stall.

CODE 43...

I am thinking the ICM or Knock Sensor? Maybe my "new" wires are actually not good?

Where to go? What to do next? Any ideas?

youve got the basics on what it could be make sure your wires are good then maybe your sensor or icm is bad.

So here I am.... I pulled off the cap and rotor. The cap was shot and the center pin was completely jammed in the cap. So replaced that. The wires were new so they look good. The distributer was pretty rusted so I cleaned that up. I started the car and about 10 seconds later the check engine light came on... Then she roughed out and stalled. I checked and I still have a 43...

Could the knock sensor cause the really rough ride and stall? What should my next step be? Should I swap out knock sensor to eliminate that as the culprit and see how it runs? What about my ICM?

HELP

i would verify wiring and voltages before buying anything

I'm inclined to agree about checking/cleaning up the wiring.

If I remember, the knock sensor will retard timing, but I doubt enough to stall it - possibly even run slightly rough, but I kinda doubt it.

luck,greg

First - Thank You for your help!

So I checked the wiring and things look OK -

I decided to check the timing. I disconnected the plug under the dash and set up my light. I can't really see any marks but there are three triangles with small "V" and a deeper bigger "V". With the truck running (Very rough and eventually stalling out) it seems to sit in the deeper bigger slot but very close to the end (or the beginning depending on how you look at it). Every time she gets real rough which is kind of "cyclical" as it "surges" then the idle drops significantly - the timing mark on the pulley shifts all over the place well outside the timing guides... Does this help at all?

I unplugged the EGR port and there was no changes to the way she runs. It is only a few months old. I put a few clips here to show you what she'* doing.



Thanks!