P38A Starting Problem

[Falk]

Indeed, sitting at the back of each bank. The other thing worth checking is your body earths (clean,bright and tight...) - i had an issue similar to this on a TD4 and once i had cleaned the body earths my mate had no further issues.

 

[Falk]

Next time it happens - if you are cranking and opening the throttle forces start let us know!

 

[oakey]

Will clean the earths and then if happens again will let you know
Thank you

 

[Zorro587]

Just swapped my fuel filter and pump and, at an extortionate cost, the pipes from the pump to the filter and return union. Car now starts as probably everybody else's does and immediately settles down. Same on LPG, no bother.

 

[oakey]

Mine is getting worse and doing this more frequently
Appears to be worse when engine half warm
Once upon a time I would have blamed mixture but have no idea what readings I should be looking at on nano

 

[Grrrrrr]

If it works cold but not when warm I would first look at o2 sensors. Assuming we're talking petrol.

 

[oakey]

Thanks Grrr Yes petrol I have no lpg fitted
I have no idea what to look for?
What is a good value etc?

 

[Grrrrrr]

Thanks Grrr Yes petrol I have no lpg fitted
I have no idea what to look for?
What is a good value etc?

Sorry. Cannot remember. Need some of the V8 owners!

@Saint.V8 @eightinavee @biggeeeee

Any idea what sort of values he should be expecting from the o2 sensors cold and hot and as he uses the throttle?

 

[eightinavee]

Oxygen sensors will have no impact on starting the engine,neither will the Maf signal.The engine ecu will not look at outputs from the Maf until it gets away from the starter motor and the oxy sensors need around 10 secs of running to get up to temp and start switching. The basics are needed to start the engine,so, most importantly you need a decent signal from the crank sensor.This will give the ecu enough info to time sparks and pulse the injectors.You don't need a cam sensor signal to start it.coolant temp sensor will make a big difference. Is this reading a plausible value ? Can you use a timing light to see if there are sparks present when cranking ?

 

[Grrrrrr]

I think he starts fine but has issues when hot?

 

[Zorro587]

So, back to where I was earlier. Mine was doing same. Cold or hot, plenty of turn but no catch until a couple or three tries. My '96 4.0 has a fuel filter (just up behind the air tank). Mine is screw unions but they can be push fit with clips apparently. I swapped pump, filter and (due to rust) feed and return pipes. All my starting woes now gone.

 

[oakey]

Thanks all
Mine sometimes starts no problem at all ans sometimes is a bitch
Almst as if I miss it first time then it is hard to get it to start
If was no spark or no fuel it would be hard to start all the time?

 

[Grrrrrr]

I am unsure how the petrol behaves. Does the petrol lift pump prime when you turn the key but not try to start? If so, if you cycle on and off a few times and then try to start will it always start?

 

[Grrrrrr]

I think he starts fine but has issues when hot?

Just reread the thread. You're right. Just starting and starting warm. Pointing at a sensor of some sort. Diag required!

 

[Wazzajnr]

I am unsure how the petrol behaves. Does the petrol lift pump prime when you turn the key but not try to start? If so, if you cycle on and off a few times and then try to start will it always start?

Common rail petrol just pressurises a manifold to a set pressure then the injectors pulse individually to release the correct amount of fuel.
If the pump is not good it could cause starting problems.

 

[oakey]

So it could be the pump? Usually it starts fine
I Have nanocom but no idea what to look for?

 

[Grrrrrr]

So it could be the pump? Usually it starts fine
I Have nanocom but no idea what to look for?

I'd suggest taking a trace and then putting the results up.

If you look at the live data and then press the floppy disk symbol (wait a bit) and then give it a filename (wait a bit) it will start recording.

Be good if BBS did a Bluetooth version so could unleash the power of your Smartphone. I'm not sure what's inside the Nano but suspect an Aduino or Raspberry Pi.

 

[Wazzajnr]

I'd suggest taking a trace and then putting the results up.

If you look at the live data and then press the floppy disk symbol (wait a bit) and then give it a filename (wait a bit) it will start recording.

Be good if BBS did a Bluetooth version so could unleash the power of your Smartphone. I'm not sure what's inside the Nano but suspect an Aduino or Raspberry Pi.

I've tried that on mine but it doesn't work. I'm guessing I need an sd card in it for it to work?

 

[oakey]

Ok I will try that thanks Grrrr

 

[Grrrrrr]

I've tried that on mine but it doesn't work. I'm guessing I need an sd card in it for it to work?

Probably. Got one in mine. They're cheap as chips.