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Help diagnosing scanner readings


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Posted

Welp, I finally barrowed a scanner off a guy I met who works for NAPA. I have it till next Sunday, so I can try this a few times. I tried to include anything I thought was vital, along with things I noted under different circumstances. Here is what I got from the initial readings.

 

Engine off/Ignition in on Position (running 10 minutes prior to this):

 

Throttle angle - 0% *Pressing pedal 1/4 - 1/2 way down pushes it to a high of 40°

TPS - .56 vlt *Pressing pedal 1/4 - 1/2 way down pushes it to a high of 2.86 vlt

Battery - 12.2 vlt

Fuel Pump Sense - 0.0 vlt

Injection Pulse - 9.7 mS *Pressing pedal 1/4 - 1/2 way down pushes it to 18 mS

Integrator - 124

Spark Advance - 0.0°

Desired A/F Mix - 13.3

O2 Sensor - 233 mvlt

Block Learn - 128

Rich/Lean Flag - Lean

Loop Status - Open

EGR - Off

Knock Retard - 0.0°

Knock Sensor - 19

Idle Air Mtr Pos - 98 steps

Barometric Press - 4.54 vlt

MAP Sensor - 2.33 vlt

 

 

 

Engine running/idling in park:

 

Throttle angle - 0%

TPS - .56 vlt

Battery - 13.6 - 13.7 vlt

Fuel Pump Sense - 13 vlt

Injection Pulse - 1.1 mS *Climbs quickly to 3.0 mS, drops way down, then back to 1.1 when pedal lightly pressed

Integrator - 127 *Will not climb over 128, & actually drops to 119 while pedal is still pressed

Spark Advance - 9.8 - 14.7 *Heavy fluctuation at times

Desired A/F Mix - 14.7

O2 Sensor - High 300's - low 700's *Responsive, heavy fluctuation

Block Learn - 125

Rich/Lean Flag - Fluctuates at idle rapidly, rich when pedal is pressed

Loop Status - Closed

EGR - Off *Same with gas pressed

Knock Retard - 13.6° - 14.0°

Knock Sensor - Continously starts at 0, counts VERY quickly to 242-253, and starts all over again

Catalytic Temp - 572.0°

Idle Air Mtr Pos - 9 steps *Jumps quickly to 40+ when pedal is pressed, then back down again

Barometric Press - 4.50 vlt

MAP Sensor - .96 vlt *Jumps to ~1.17 with light pedal press, then to around .50, & back to .90 - .96

 

 

 

Driving around 20 MPH/occasional heavy throttle:

 

Throttle angle - 80% max when pushed hard

TPS - 3.33 vlt max when pushed hard

Battery - 13.4 - 13.7

Fuel Pump Sense - 13 vlt *very small range of fluctuation

Injection Pulse - 8.6 mS max when pushed

Integrator - 128 max at WOT, will hit 130's when you first get back off the gas

Spark Advance - Heavy fluctuation from 12.2° - 16.8° @ a stop, ~25 @ light throttle, full throttle lowers it to 17°

Desired A/F Mix - 14.7

O2 Sensor - Still responsive, hitting the low 900's for a high

Block Learn - Will not pass 128

Rich/Lean Flag - Fluctuates with no throttle, rich when getting on it

Loop Status - Closed

EGR - On for a split second when pushing it, & off again even while pedal is still depressed

Knock Retard - 14.0° steady

Knock Sensor - Still doing the same thing as in park, throttle makes no difference

Catalytic Temp - 599.0°

Idle Air Mtr Pos - 80 steps when pushed

Barometric Press - 4.54 steady

MAP Sensor - 2.68 vlt max

 

Well, there you have it. First things that sticks out is the knock sensor, which appears to be going nuts, and may also be causing some of the other off readings. Then there's the throttle angle/TPS voltage being low (which is also one of the codes I have), and doesn't move when the car is started. I will try unplugging the TPS and seeing what kind of readings I get (should be default, correct?). I would have done it today, but the engine was just too damn hot. The others codes I had before I started were 33, MAP sensor voltage low, and 43, ESC, which is most likely due to the KS. You can see there is QUITE a bit of KR, which is probably causing shuttering feeling I get (almost like a fuel cut off) when I got on the throttle. I *think* that's the max timing it will cut. Is this because of the sensor itself, or is there still a possibility of internal motor problems? I'm guessing the sensor is fried, or there's a wiring issue since it's still getting a reading even with the engine off. Anything else stick out to anyone? If I should conduct any other test while I still have the scanner, do tell. If you need further clarification on anything, or more info, let me know. Any help would be super duper appreciated!

Posted

Is this a TGP?? If it is then the first thing I would start with the knock sensor, but then change the memcal if that doesn't fix that code. As far as the MAP code I would guess a crack in the vacuum line running to it. A whole new vacuum line set is ~$25 from GM so you may as well replace the whole thing if it's cracked.

Posted

Yes, it's the TGP. Yeah, I was thinking about starting at the KS first, too. I already bought a new one a few months ago when I was suspecting that was the culprit. Then we'll go from there, see what it does. I keep forgetting to pick up the vacuum lines set from the dealer, too. You wouldn't happen to have the part number, would you?

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