Missfire no CEL

[AuroraGirl]

When i drive it completely normal like an old man you cant hardly tell theres an issue it really only does it when i punch it, i cant really tell what rpms or speed because the guages read completely wrong like 90mph on the guage is really about 60 and the rpms read like 3500 on the guage wich seems to be what it would be at if i were really doing 90 but my scan tool reads it correctly

sounds like your truck has the wrong tire size calibrated
Pretty sure thats going to **** with misfire monitors since the car thinks the engine is spinning at different speed/load and it cant filter rough road stuff

 

[Osteoblast]

You mean cmp timing? That needs to be 0 +-2 degrees.

 

[AuroraGirl]

You mean cmp timing? That needs to be 0 +-2 degrees.

One thing it for sure has to be is set to the procedure not just fiddled with

 

[Supercharged111]

sounds like your truck has the wrong tire size calibrated
Pretty sure thats going to **** with misfire monitors since the car thinks the engine is spinning at different speed/load and it cant filter rough road stuff

Our trucks predate the rough road stuff. I've only dealt with that in the 1 MB PCM GMT800 trucks.

 

[AuroraGirl]

Our trucks predate the rough road stuff. I've only dealt with that in the 1 MB PCM GMT800 trucks.

Makes sense. I know GM when it came to TBI there was a 1 knock sensor period and I dont know if it ever went to 2 knock sensors? But the LT1 got 2 knock sensors, but it had more complex PCM and stuff.

Then I suppose a 96 might have 2 knock sensors?

 

[Supercharged111]

Makes sense. I know GM when it came to TBI there was a 1 knock sensor period and I dont know if it ever went to 2 knock sensors? But the LT1 got 2 knock sensors, but it had more complex PCM and stuff.

Then I suppose a 96 might have 2 knock sensors?

Only the big blocks got 2, small blocks just had 1.