Hello all,


I have a 1999 Blazer lt with the 4.3 vortec engine with 260,000 miles on it. It has been throwing a misfire when I drive up hill only. Not every time but it is becoming more consistent. When the misfire occurs I feel nothing. No loss of power, no skip, nothing. Other than this one issue the truck starts and runs like a champ.


Before I throw more money into it I wanted to post my OBD II reading and see if anyone out there can tell if something stands out. I will be fixing the issue but if I can avoid a costly process of elimination it would be best. I have the code reader but an a novice at understanding the detail. This is what came up this time.


The SES flashed this morning while driving up hill with a 40 to 60 mile an hour head wind (thank you northern Nevada weather).


Misfire cylinder 6 ( this is the first time it has specified a cylinder)


ABSLT TPS % 46.7
ENGINE RPM 2021
CALC LOAD % 27.5
MAF 5.33
MAP ("HG) 23.0
COLLANT 199
LT FTRM1 20.3
ST FTRM1 5.5
LT FTRM 2 21.1
ST FTRM2 6.3
SPEED 46
FUEL SYSTEM 1 CLSD
FUEL SYSTEM 2 CLSD


Please let me know your thoughts. My plan is to start with the basics of plugs, wire, rotor and cap. But that without labor is $155.00. If the problem looks to be something else according to the readings I would prefer to spend smart.


I am usually not such a penny pincher when it comes to my Blazer, this year so far I have put $2000.00 into it, fuel pump, shocks, idler arm, coolant, tranny flush and brake fluid flush. I am just running out of money at the moment and I don't want to ignore a problem that could create a bigger problem.


Any help would be much appreciated. When my husband was alive this I am sure would be an easy fix for him.