Help with 1999 B5254t - cranks but won't start Topic is solved

[bmdubya1198]

It might be an O2 sensor. Can you get a signal from that? A bad O2 sensor will cause the car to run like crap.

[pvfjr]

I can take a closer look at the O2 sensors.

I just got a new ELM adapter yesterday after losing my old one. I didn't see the LTFT in the list on Torque lite for some reason? The STFT was there, but is slightly less telling. I'll try driving up and down a hill nearby and see if the O2 and STFT responses make any sense.

[bmdubya1198]

Go into the "Torque Scan" option, then tap the menu at the top and select "O2 Sensor." See what bank 1 sensor 1 and bank 1 sensor 2 show. They should be oscillating. If it's a flat line, it's no good.

[pvfjr]

I don't have a "Torque Scan" option. Do you have the lite version or the pro version? All I can do is add displays to page, it's a bit tedious. I wish I could just look at the raw data live. Is the pro version better than this? My old hard-wired scanner will show the LTFT and STFT, but the MAF field registers 0. It's clunky and slow to navigate, but its limited features seem to work OK.

If I unplugged the O2, should this thing go open loop and run better? Maybe if I did a ECU reset to clear the erroneous LTFT first?

[abscate]

Unplug the MAF then start up and see how it runs on the lookup table.

You probably also still have a weak coil or two, think about replacing them all.

[bmdubya1198]

I don't have a "Torque Scan" option. Do you have the lite version or the pro version? All I can do is add displays to page, it's a bit tedious. I wish I could just look at the raw data live. Is the pro version better than this? My old hard-wired scanner will show the LTFT and STFT, but the MAF field registers 0. It's clunky and slow to navigate, but its limited features seem to work OK.

If I unplugged the O2, should this thing go open loop and run better? Maybe if I did a ECU reset to clear the erroneous LTFT first?

I take that back, do you have a "test results" option? You might not, since I have Torque Pro. Funny, my Torque won't show any fuel trim either. I remember trying to see it when my MAF sensor was gummed up with air filter oil.
You could try unplugging it.

+1 to abscate.

[pvfjr]

Something even funnier, my old scanner doesn't show O2 sensor 1, but sensor 2 seems fine. Torque lite shows sensor 2 working fine, but shows an empty graph for sensor 1. I'm not sure if I should assume that sensor 1 is dead, or if I'm just not getting the days for some reason.

[bmdubya1198]

Hmm... that is odd. Check the connection on the sensor and make sure the wires are in good shape. It might be a dead O2 sensor.

[pvfjr]

Hmm... that is odd. Check the connection on the sensor and make sure the wires are in good shape. It might be a dead O2 sensor.

I'll be throwing it back up on the lift to do just that. I just figured the scanners would report 0 volts if it was dead, or the ECU would throw a code. Is there a wiring diagram that would allow me to do a manual voltage check with a multimeter?

[bmdubya1198]

Hmm... that is odd. Check the connection on the sensor and make sure the wires are in good shape. It might be a dead O2 sensor.

I'll be throwing it back up on the lift to do just that. I just figured the scanners would report 0 volts if it was dead, or the ECU would throw a code. Is there a wiring diagram that would allow me to do a manual voltage check with a multimeter?

You might be able to find one here http://volvowiringdiagrams.com/