'01 no start/code question

[blaisetd]

Yesterday the wife's '01 4.0 auto w/ 60k did not start after work. (just turns over) I pulled the codes and came up with P0142 "o2 sensor circuit malfunction bank 1 sensor 3" and P0455/P0456. The later two (emmisions leaks) i had previously. Question: will the O2 code cause the no start and IIRC aren't there two sensors before the cat and one after? Sorry, the XJ is still at her work. Any way to know which O2 is the bad one? thanks in advance blaise

[blaisetd]

bump

[90xj06]

there is one sensor before and one after. and i do not think the o2 will cause a no start. i would check cam and crank speed sensor.

[blaisetd]

i would check cam and crank speed sensor.

even though there is no code for the CPS?

[langer1]

The 01 and newer has 3 o2s before the cat and one after. o2 sensors should not cause a no start. The CPS will but it will set a code, no fuel pressure will not set any codes accept perhaps o2 voltage low or lean.

[90xj06]

wow 3 o2 sensors. alittle over kill if you ask me.

[langer1]

wow 3 o2 sensors. alittle over kill if you ask me.
One on each tube or bank, that way the fuel can be adjusted for two cyclinders not just the same for all 6.

[blaisetd]

cleared the codes, disconnected the battery and reconnected. Disconnected the CPS and reconnected. No fuel pressure at rail. Does a bad CPS stop the fuel pump?

[langer1]

cleared the codes, disconnected the battery and reconnected. Disconnected the CPS and reconnected. No fuel pressure at rail. Does a bad CPS stop the fuel pump?
NO

[lilredwagn]

IIRC, to (hopefully) clarify (and langer please correct if I'm wrong yet again), The CPS failure (as well as an ASD circuit failure) will not directly affect the fuel delivery, but they do both prevent spark - you will have initial fuel pressure from priming and perhaps a second or two of cranking, but after that, when the ECU realizes it's not getting spark, it WILL shut down the fuel circuit.

So, if you actually measured zero pressure at the rail with a pressure gauge, then it is indeed not a CPS or ASD issue (and is likely a bad fuel pump) ... IF you are just going by whether the plugs are dry after cranking, then you need to get a pressure gauge, because if you aren't getting spark, the plugs will be dry whether you have fuel or not.

[90xj06]

if you are seeing 0 psi on the fuel rail. it is because of the evaporate system leak. im wondering if because it knows it has a leak it shuts down to prevent a fire from escaping fuel vapors. but this is one of those things the litle voices say in my head.

[blaisetd]

Put a guage on it and it never registers any pressure when cranking. Nor do i hear the fuel pump run or prime....

[blaisetd]

bad fuel pump. Fixed. Thanks for the help. blaise

[Saudade]

From the 2000 FSM:

"The PCM monitors the crankshaft position sensor. If the PCM does not receive a crankshaft position sensor signal within 3 seconds of cranking the engine, it will shut down the fuel injection system."