Deciphering Live Data.

[Nick88]

Wonder if his idle is high because throttle isn’t fully closing.

Possible. Idle was never high before and with cable disconnected it drops back down to like 600

 

[Nick88]

Looks like your TPS is malfunctioning.

What problem are you trying to diagnose?

Truck is extremely sluggish and down on power, seems like timing is having trouble advancing and now at low acceleration it surges a bit, low as in really really low.

 

[Nick88]

idk...tps reads where it should at closed throttle....but then it's saying that percentage....

Dont know why its doing that, the tps itself I have tested and it is correct at around .54 volts when gas pedal is not touched.

 

[scott2093]

It seems like the truck is having a timing advance issue in general, it advanced but not enough causing it to be super sluggish.

You need to make sure those knock counts aren't real and causing the computer to constantly retard your timing...
I'd put timing back to zero to make sure you get things working right there.

 

[Nick88]

You need to make sure those knock counts aren't real and causing the computer to constantly retard your timing...
I'd put timing back to zero to make sure you get things working right there.

Truck is set to zero, new knock sensor, new delco icm, new knock sensor wire, all new connectors, ESC tested to be good, new ECM, every ignition advance item is replaced and new.

 

[scott2093]

Truck is set to zero, new knock sensor, new delco icm, new knock sensor wire, all new connectors, ESC tested to be good, new ECM, every ignition advance item is replaced and new.

hmmm..You said your exhaust is loud?
Wonder if you could rig up a test setup to see what the knock sensor is actually doing.
did you torque the knock sensor exactly how it should be and verify ground???

I'll try to look at your manual when I get a chance..You should be able to at least tap into behind the ecm with a meter.....

Maybe not relevant but I had 2 new AC Delco knock sensors that didn't work correctly. Ended up finding an NOS one of thee bay...new parts can be sketchy these days unfortunately....
Not saying that's the case but, I'd definitely get to the bottom of why you're seeing all those knock counts...
computer literally retards the timing every time one happens....so it would be nice to know if they are actual knocks to rule that out...

have you tried seeing if there are any codes stored?

your post #5...was the key/truck off when you took that screenshot?

 

[Nick88]

Truck has a slight exhaust leak on the passenger side, exhaust itself is pretty loud.

Torque is exact and I tightened and loosend it previously a bit to try to make sure good ground.

Yes I think the knocks are my issue as the truck feels like crap accelerating probably mac retard on timing, at idle and revving the knocks do not increase and just stay at 1, but the exhaust leak also doesnt make any noise, the engine revs smoother.

No codes at all.

Dont remember but I would assume because battery is at 0 Volts, I believe I did shut it rught before taking that.

What is max retard with the knock sensor? Is it like max max that it can pull almost all timing or does it top out at like 8 degrees, I wonder if its 8 degrees if I can set the truck 8 degrees advance and have an aggressive idle but regular timing once truck starts going. I wonder also, I replaced my knock sensor wire to rule that out but all I had around was some thick 10 gauge wire, could that cause issues???

 

[scott2093]

Dont remember but I would assume because battery is at 0 Volts, I believe I did shut it rught before taking that.

That would make sense with some of the bizarre readings...

I wonder if its 8 degrees if I can set the truck 8 degrees advance and have an aggressive idle but regular timing once truck starts going

Doing that could actually cause knocking...seems like fighting upstream...neat theory though....

10 awg wire isn't going to hurt anything...unless the weight of it pulls apart something maybe....

Here are 2 pages from your 88 Emissions manual from the sticky section. I know you don't have codes but it shows the operation of the circuit so you can test some things or devise a test to rule out anything funky in the circuit....
I'll look back at it...
I think Schurkey is familiar with the 88...Hopefully he'll have some advice....

 

[Nick88]

That would make sense with some of the bizarre readings...

Doing that could actually cause knocking...seems like fighting upstream...neat theory though....

10 awg wire isn't going to hurt anything...unless the weight of it pulls apart something maybe....

Here are 2 pages from your 88 Emissions manual from the sticky section. I know you don't have codes but it shows the operation of the circuit so you can test some things or devise a test to rule out anything funky in the circuit....
I'll look back at it...
I think Schurkey is familiar with the 88...Hopefully he'll have some advice....

Im starting to wonder if it some sort of injector issue. The truck had developed a pretty good misfire on start and pretty consistent under light load. I just checked and recently my passenger exhaust (true dual) was full of carbon but the driver was fine. I just checked and at idle the truck is putting out some hefty blue smoke out the passenger side but the driver is next to nothing, I wonder if rhe mis is on that side and gas/ oil are just raw getting into exhaust or if it is one injector is dumping fuel, I know each injector feeds each bank of the motor but its an idea, they are original injectors and the original injector connectors (which are extremely loose feeling)

 

[Schurkey]

My MTG2500 scan tool had a few options within the "Engine" menu. There was an option for checking "Codes and Data", and an option for checking codes and data while road testing.

The road-test Codes & Data check allowed normal idle speed. The non-road-test code 'n' data check raised the idle to ~1000 rpm.

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Depending on how your scan tool is set up, that's likely the reason for the higher rpm when the tool is connected.