1998 yukon Mystery p0300 and rough idle still

[Fless]

If you're using Torque Pro this link might have the correct values to add a PID:

Diagnosing P0300 code & Camshaft Retard Offset Adjustment Using Torque App

This post may help you if you have the dreaded P0300 code on our Vortec engines. First you need the info to add the PID in the Torque App here are screenshots of the info you need to enter: The part you don't see at the bottom is the OK button to save the PID. Once you save it by hitting...

www.tahoeyukonforum.com

Would be nice to have confirmation of it if anyone adds it and it works okay.

 

[OilBurner2003]

If you're using Torque Pro this link might have the correct values to add a PID:

Diagnosing P0300 code & Camshaft Retard Offset Adjustment Using Torque App

This post may help you if you have the dreaded P0300 code on our Vortec engines. First you need the info to add the PID in the Torque App here are screenshots of the info you need to enter: The part you don't see at the bottom is the OK button to save the PID. Once you save it by hitting...

www.tahoeyukonforum.com

Would be nice to have confirmation of it if anyone adds it and it works okay.

I am using Dashcommand, the other gentleman helped me through it. Thank you though!

 

[east302]

You’re just a tad out of spec, your high value showing 4.1 degrees. I’d get it into spec but, from your earlier photo of the cap, was thinking you’d be out more.
While you’re at it, add the PIDs for the misfire counts on each cylinder and see what they show.

 

[OilBurner2003]

You’re just a tad out of spec, your high value showing 4.1 degrees. I’d get it into spec but, from your earlier photo of the cap, was thinking you’d be out more.
While you’re at it, add the PIDs for the misfire counts on each cylinder and see what they show.

View attachment 385487

Will do that first thing in the morning! Also, This might be jumping the gun, but do you think that can cause rough idle or a p0300? I'm guessing a no, I'm just wondering is all.

 

[east302]

That would be a hesitant “maybe”. When I saw your picture of your cap with the plug wires hitting the intake, it just looked really “off” compared to my 350s.

I’d expected you would come back with a higher degree on that correlation, but it’s not too far off and I kind of doubt that the correlation itself is your issue. But, it doesn’t hurt to fix it.

One thing would be to put the engine to #1 TDC on compression stroke and see if the rotor is aligned with the #1 post under the cap and pointing at the little “8” triangle just below it on the distributor housing. Pull the ignition coil wire and rotate the crank to align the harmonic balancer line with the index tab. If the rotor is pointing at the firewall, rotate the crank 360 degrees, align the marks and that should be cylinder 1 TDC.

Pictures borrowed from the internet:





It kind of goes back to your older photo and whether or not that distributor was stabbed right to begin with.

 

[OilBurner2003]

That would be a hesitant “maybe”. When I saw your picture of your cap with the plug wires hitting the intake, it just looked really “off” compared to my 350s.

I’d expected you would come back with a higher degree on that correlation, but it’s not too far off and I kind of doubt that the correlation itself is your issue. But, it doesn’t hurt to fix it.

One thing, short of pulling the distributor, would be to put the engine to #1 TDC on compression stroke and see if the rotor is aligned with the #1 post on the cap or pointing at the little “8” triangle just below it.

It goes back to your photo and whether or not that distributor was stabbed right to begin with.

Roger, regardless, something that needs to be fixed. If I fix it correctly and nothing happens, oh well. It needed to be done anyway. If it miraculously fixes everything that’s happening, that would be pleasant as well. I will update you on it tomorrow sir!

 

[OilBurner2003]

That would be a hesitant “maybe”. When I saw your picture of your cap with the plug wires hitting the intake, it just looked really “off” compared to my 350s.

I’d expected you would come back with a higher degree on that correlation, but it’s not too far off and I kind of doubt that the correlation itself is your issue. But, it doesn’t hurt to fix it.

One thing would be to put the engine to #1 TDC on compression stroke and see if the rotor is aligned with the #1 post under the cap and pointing at the little “8” triangle just below it on the distributor housing. Pull the ignition coil wire and rotate the crank to align the harmonic balancer line with the index tab. If the rotor is pointing at the firewall, rotate the crank 360 degrees, align the marks and that should be cylinder 1 TDC.

Pictures borrowed from the internet:

View attachment 385488

View attachment 385489

It kind of goes back to your older photo and whether or not that distributor was stabbed right to begin with.

Today I have been trying to get the CMP correlation just right, and I've actually encountered a problem. For some reason, You have to turn the cap and rotor and shove it against the intake to even get a negative reading. it's -0.8 when it's turned all the way against the intake, and it won't go further than that. It's like the previous mechanic just shoved it in there or something...What are your thoughts on this?

 

[east302]

Zero is your target, so if you’re at -0.8 then you’ve technically gone too far. Realistically, that’s within spec and pretty damn close.

 

[east302]

-2 to +2 is within spec, zero being optimal

 

[OilBurner2003]

Zero is your target, so if you’re at -0.8 then you’ve technically gone too far. Realistically, that’s

Roger! I’ll try and adjust the app so I get better live data. Oh, also, I figured you guys might want to see this. This is at idle mind you. I better pray to god it’s a distributor issue, kinda makes sense for p0300 now that I see this.