Surging and bucking when warmed up

[PlayingWithTBI]

Ok so not sure what I need to be looking for because I'm not familiar at all with this stuff bet here are some pics and videos. It's doing some new stuff now. In gear the idle jumps way up.

Why don't you download TunerPro RT, WinALDL is pretty much obsolete. We have more people familiar with TP.

 

[short1500]

Why don't you download TunerPro RT, WinALDL is pretty much obsolete. We have more people familiar with TP.

I will down load tomorrow and give it a try if I can figure out how to.

 

[short1500]

Stop looking at the "RAW data" tab. It's useless until converted into a number that means something. "Sensor data" would be enormously better.

Seems like the IAC doesn't move.

Battery voltage seems a bit low.

"Rich Lean counter" is--apparently--what I'd call "cross-counts" of the O2 sensor. Number is WAY higher than I'd expect. Maybe an artifact of the scan tool, not the actual computer/sensor system.

First picture is in park at idle and 4th is in gear

 

[short1500]

Ok I downloaded Tunerpro RT. Not sure what I need to look for I have videos of everything from cold start to warmup. I noticed it was never in open loop always closed and the spark advance is jumping all the way and back down. I need to figure out how to download the video.

 

[short1500]

Ok so I ran my truck on Tunerpro RT and at cold start it's showing it's in closed loop. It's also showing 4 knock counts, timing sweeping from 0-40 at idle, IAC position 66 at idle, O2 MV jumping around from 180 to 880, vacuum 20, MAP 28, TPS volt 0.68, AFR 7.3, BLM 134.
Should the ECM be in open loop when in cold start and go into closed loop when warm? Should the spark advance be jumping from 0-40 and back down at idle ? What would cause this? Anyway if I can't get this figure out the truck has to go.

 

[Schurkey]

at cold start it's showing it's in closed loop.

Shouldn't be. O2 sensors need some time to warm-up, and until then it should be in open loop.

Is this a REAL problem, or is this a screwup in the scan tool? My guess is that it's a problem with what the scan tool reports, not what the vehicle is actually doing.

It's also showing 4 knock counts,

At idle? Is there mechanical noise--lifter tapping, rod knock, piston slap, cracked flexplate, etc. that the knock sensor could mistake for "knock"?

timing sweeping from 0-40 at idle,

Seems unreasonable. Idle speed must vary considerably. If not...maybe another scan tool screwup.

IAC position 66 at idle,

Does it ever change? If the timing is advancing and retarding, I'd expect the IAC position to vary also. Has someone dicked with the throttle-body base idle screw? Is that screw still sealed behind it's "tamper-proof" cover? If not, you'll need to re-set proper base idle.

O2 MV jumping around from 180 to 880,

Seems reasonable IF the O2 sensor is hot enough to be effective.

vacuum 20,

WHAT vacuum? There's no vacuum sensor...

MAP 28,

...there's a Manifold Absolute PRESSURE sensor, and if that's displaying in inches of mercury, the engine has almost no vacuum.

TPS volt 0.68,

A little high at idle.

AFR 7.3,

Insane. Should be 14.x

BLM 134.

Not way out of line. 128 is "perfect", but I wouldn't be concerned about 134.

Should the ECM be in open loop when in cold start and go into closed loop when warm?

Yes. The O2 sensor has to be hot, there's maybe a timer and a minimum coolant temp also.

Should the spark advance be jumping from 0-40 and back down at idle ?

No.

What would cause this? Anyway if I can't get this figure out the truck has to go.

I don't know Tuner Pro. I can't help.

 

[short1500]

Shouldn't be. O2 sensors need some time to warm-up, and until then it should be in open loop.

Is this a REAL problem, or is this a screwup in the scan tool? My guess is that it's a problem with what the scan tool reports, not what the vehicle is actually doing.


At idle? Is there mechanical noise--lifter tapping, rod knock, piston slap, cracked flexplate, etc. that the knock sensor could mistake for "knock"?


Seems unreasonable. Idle speed must vary considerably. If not...maybe another scan tool screwup.


Does it ever change? If the timing is advancing and retarding, I'd expect the IAC position to vary also. Has someone dicked with the throttle-body base idle screw? Is that screw still sealed behind it's "tamper-proof" cover? If not, you'll need to re-set proper base idle.


Seems reasonable IF the O2 sensor is hot enough to be effective.


WHAT vacuum? There's no vacuum sensor...


...there's a Manifold Absolute PRESSURE sensor, and if that's displaying in inches of mercury, the engine has almost no vacuum.


A little high at idle.


Insane. Should be 14.x


Not way out of line. 128 is "perfect", but I wouldn't be concerned about 134.


Yes. The O2 sensor has to be hot, there's maybe a timer and a minimum coolant temp also.


No.


I don't know Tuner Pro. I can't help.

There is no mechanical noise at all while engine is running, The throttle body base idle screw is sealed and idle is stable while running.

 

[Schurkey]

If the idle is stable, I don't see how the timing advance can vary 40 degrees.

I don't know TunerPro, but my suspicion is that this is a scan-tool error, not an engine-running error.

 

[termite]

so I ran my truck on Tunerpro RT

Confirm you are using the correct definition for your ecm. I'm no help with it as I'm trying to learn it myself. Several threads on here with some guidance you may be able to draw from for the basics with tunerpro.