1990 chevy missing, runs like crap

[misfits]

I have a 2wd 1990 chevy 1/2 ton with a 305. I replaced the gas tank, sending unit and fuel pump and starting having problems with the truck running poorly. It stumbles and misfires. On light acceleration it runs like crap. But on heavy acceleration it sounds/runs fine.
So i replaced the fuel filter, cap, rotor, plugs and wires and one of the plugs had the electrode basically melted off. After that it ran fine for about 2 days now it runs like crap again.
The engine light isn't on but during a 15 min drive the light came on once or twice around 10 min into the drive then went off again. It did that 2 different times.
I scanned for codes and I got a 13 and a 42. I have a code 42 a while back and re connected the timing connector and cleared the light but apparently its still storing a code 42.
Is an oxygen sensor going to affect how the engine runs?

[ChevLoRay]

It is quite possible. The 02 sensor samples the combustion gasses and, as an imput to the CPU, the CPU takes that information and other pieces of data and tells the engine what to do.

Do a search for code 42 and I am sure you'll find other information. If the SES/Check light comes on periodically, you can be sure that it is storing codes. Do a search for ALDL and you'll also pull up some information about that system and many tests that can be done to help determine the problem.

I was going to have some fun with your title and say, "If it is missing and running like crap, whoever took it will soon find out" But, that wouldn't be right, would it?

Hopefully, the search will help you with trouble-shooting. There are knowledgeable people on here who can offer you plenty of suggestions about how to trouble-shoot and what to look for.

[88K2500]

Originally Posted by misfits

I have a 2wd 1990 chevy 1/2 ton with a 305. I replaced the gas tank, sending unit and fuel pump and starting having problems with the truck running poorly. It stumbles and misfires. On light acceleration it runs like crap. But on heavy acceleration it sounds/runs fine.
So i replaced the fuel filter, cap, rotor, plugs and wires and one of the plugs had the electrode basically melted off. After that it ran fine for about 2 days now it runs like crap again.
The engine light isn't on but during a 15 min drive the light came on once or twice around 10 min into the drive then went off again. It did that 2 different times.
I scanned for codes and I got a 13 and a 42. I have a code 42 a while back and re connected the timing connector and cleared the light but apparently its still storing a code 42.
Is an oxygen sensor going to affect how the engine runs?

If you replaced all those parts and still have a misfire, you should do a compression check on all cylinders. Maybe you burnt a valve. Who knows. The compression check will tell you where the miss fire is. If the compression checks out good on all cylinders, I would start looking at the dizzy again.

[88K2500]

Code 13 = O2 Sensor.

Here's something I had saved on my computer.

TBI Trucks -

Trouble Codes


12. No reference pulses to Electronic Control Module (ECM). You will get this code when checking for error codes because the engine is not running.
13. Oxygen sensor signal stays lean during warm engine cruise, your O2 sensor could be unplugged or faulty wire.
14. High temperature indicated at engine coolant temp. sensor. Sensor could be unplugged or faulty wire.
15. Low temperature indicated at engine coolant temp. sensor
21. High voltage at throttle position sensor. Sensor could be unplugged.
22. Low voltage at throttle position sensor
23. Low temperature at manifold air temperature sensor
24. Circuit fault in vehicle speed sensor
25. High temperature at manifold air temperature sensor
29. Fault in 4th gear switch
32. Fault in exhaust gas recirculation valve diagnostic switch
33. High voltage (low vacuum) at MAP sensor.
34. Low voltage (high vacuum) at MAP sensor.
41. Cylinder select error
42. Fault at electronic spark timing circuit (sets when timing is set also, clear code and verify that it does not return.)
43. Low voltage at electronic spark timing circuit
44. Oxygen sensor lean
45. Oxygen sensor rich
46. Fault at vehicle anti-theft system
51. PROM error
52. Low voltage at oil temperature sensor
53. High voltage at battery
54. Low voltage at fuel pump OR Low voltage at Fuel pump relay
55. Problem at Electronic Control Module (ECM) - ECM failure OR Serial bus error
62. High voltage at oil temperature sensor

CLEARING THE TROUBLE CODES
Turn the key switch to the off position. To clear any trouble codes, disconnect the battery for 30 seconds or unplug the connectors to the ECM. If this is done at the battery, you may loose your preset stations on your stereo A better place to remove power is at the fuse.

For a more informative diagnastic look at your system you will need a laptop computer, and ALDL cable and a free program called winALDL from here.
http://winaldl.joby.se/[/I][/B]

[misfits]

Thanks for the info. Im going to check the o2 sensor and see if replacing it get it to run any better. If not I think im going to have a local shop look at it as im getting sick of messing with it.
Lol @ ChevLoRay, The title could be misleading... Id feel sorry for the guy who would have taken it lol.

[misfits]

I finally took chevytech's advice and replaced the distributor module even though autozone said it tested ok... It seems to be running better now with the replacement. Im going to give it a few days before I consider it "fixed" though. Now im going to ditch the catalytic converter before that gives me problems, sorta preventive maintenance...