1990 Chevrolet Truck



February, 8, 2007 AT 1:07 PM

I have a 90 chevy Scottsdale 1500. 130000 miles
It is running a 350 with throttle body injection.
One day just quit. Brought it home and it started, lot of black smoke. Found 2 codes on the computer, O2 sensor (found broke) and temp switch (below -27 for 30 seconds at start-up).
Changed the 02 sensor, gave a complete tune-up.(Plugs, wires, cap, rotor, fuel filter, air filter) Has never had a tune up since I have owned it, so it was due.
Tried to start, would not start. Thought may need some gas to prime the fuel filter(?) Put some into the throttle body after a few tries it started.
Pulled it out of the barn and let it warm up.
Turned it off. Would not restart. After a few times it finally started. RUN GREAT. Took it for a ride, got down the street and it died again. Restarted it would only run full throttle with no RPM's. After about 3 or 4 minutes of running that way I let it stall out. Got out of the truck and found the muffler RED hot (glowing).
Thught it to be a pluged cat. Converter. Cut the cat. Out. No change can not restart at all. It has good spark, fuel comming thru the injectors and cranks fine.
The only code is 15 (temp below -27 degrees for more than 30 seconds)
I do not know how to reset that code.
Any help would be great.

Thank you



6 Answers



February, 8, 2007 AT 5:25 PM

You can reset the vehicle's computer. And by extension erase the code. By disconnecting the battery for at least ten minutes. Disconnect the battery only while the vehicle is off.



February, 9, 2007 AT 6:51 PM

Start by replacing your coolant temp sensor. With a reading of -27, your ECM will dump lots of fuel. This will result in hard or no starts and fill your exhaust with raw fuel. This is probably making your eahaust red hot. Also, check your engine oil, it may be contaminated with fuel as well. It is a good idea to change it anyway.
To clear your code after the repair, use a scan tool, or remove the " POSITIVE " battery cable for at least 10 seconds. You will have to drive the vehicle for about 20 minutes to reset all peramiters.
Good luck



February, 9, 2007 AT 7:16 PM

Stuck in the Open Loop check the CTS.

CTS and O2 sensors are partner in crimes. Its dumping fuel that's why the Cat is glowing.

Also could be leaking injectors and pressure regulator probelm.



February, 10, 2007 AT 9:24 AM

Changed the temp sensor.
It was bad but it still does not start.
Sounds better, it seems to fires on a couple on cylinders (when pumping the pettal) but it will not start.
Any other things to check?
No codes in the computer now.



February, 10, 2007 AT 4:18 PM

Look for spark on every wire while cranking. Okay-check the fuel pressure with a gauge. Any luck?

No spark check the coil pos. Terminal-none check fuse/'ignition switch



February, 13, 2007 AT 6:44 AM


It was the combo of the O2 sensor and the Temp Sensor together.
The temp sensor told the injectors to spray way too much fuel flooding the engine completely.
I pulled all the plugs and let it just sit for a day to air it all out.
Put the plugs back in and it fired right up!

Running good not, thanks to everyone for the help!

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