1991 Chevy 1500 4.3L TBIThe truck starts fine but looses power while driving up an incline within the first 10 minutes of driving.


Asked by Jul 15, 2013 at 09:47 AM about the 1991 Chevrolet C/K 1500 Scottsdale Extended Cab LB

Question type: Maintenance & Repair

The truck will do this a couple of times, then will drives fine for the rest of the day. It only does it when initially driven that day. We thought it was temperature related so we warmed the truck up for about 10 minutes then drove it. There was no change! It is possible that the current thermostat is opening too soon and engine temp is not coming up until under load. Not sure. Any suggestions are appreciated.

6 Answers

This one 2winSpin.....is going to be a "get your OBD scanned" There are just so many many possibilities that to eliminate so much guesswork, opps just saw 1991. Dangit. Well. you can still get some codes by the flashes and pattern of CEL. Do you know how to do that? Let me know if not and I will write out how.

Andrew Olsen

check ign timing


Thank you guys. I do not know how to get the flashes you mentioned, your help is appreciated. Thanks!

Ground terminals A and B (see diagram below) with the ignition "ON" and engine not running. The system will enter the diagnostic mode. In this mode, the computer will display a Code 12, three consecutive times, by flashing the "CHECK ENGINE", "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR LAMP" or light. A Code 12 consists of one flash, a short pause, then two flashes in rapid succession.

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After Code 12 is displayed, any stored trouble codes will be show . Then go to http://www.obd-codes.com/trouble_codes/gm/gm-2-digit-codes.php for a list of specifics

This is just a small sample of a very long list: code - code definition 12- diagnostic mode///// 13- 02 sensor or circuit////// 14- coolant sensor or circuit/ high temp indicated//////// 15- coolant sensor or circuit/ low temp indicated//////// 16- system voltage out of range ......BUT BEFORE we get carried away, let's keep it simple: Andrew up there has a good idea...listen to him, timing

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