Symptoms: Does this sound like fuel pump on its way out?

[cisco]

White Super S has these symptoms lately:

- Although battery is fully charged and starter motor cranks over really strongly and quickly, the engine takes a while to start, constantly turns over for quite a while, and sometimes takes 3 turns of the key to get it to start. Sounds like fuel is scarce or something, the starter motor is really trying so hard and nothing to do with battery, its got plenty of grunt.

Then when it does start, it sounds a bit weak and jumpy for a few seconds before kind of idling reasonably happily.

Idle is also very low lately, can idle at around 300-400rpm and sounds like it is on the edge of stalling a lot of the time.

Fuel pump on the way out? Any other ideas??

Car also chewing a lot of petrol and has for a while.. Definately ECU either in closed loop mode or something not right causing it to guzzle petrol.

Only modifications now are extractors and different air intake pipe.

I was thinking that o2 sensor should be replaced to see if that fixes the fuel consumption, but lately this starting problem makes me think there is a second problem.

All ideas welcome. I did the throttle body re-soldering trick a few months ago, so shouldn't be that.

Thanks.

 

[CMF_jamm'n]

this sounds exactly like toms car. he thoguth it might be a leaky injector.

 

[CMF_Yom]

Not exactly like charlotte. She's only has the issues when inbetween hot/warm. And it doesnt take that long to start either.

When she is cold it is fine, when it is wet she gets angry at me and when i don't drive her she's also angry at me.

But yeh, if it happens when cold as well as just been driving hot thats definately not good.

Try turning the key to ON and waiting for the fuel pump to finish priming the system and then try and start it. That can put the problem down to something in the fueling system.

 

[CMF_White Knight]

Ha,ha !! Same problem sometimes with Family Hack. Sometimes it will start first time other times you got to crank the starter motor 2/3 times and when it does fire it runs real lumpy until you pump the pedal a few times.
Cisco exactly same problemas you. My fuel consumtion okay and had the O2 sensor replaced a while back as well as having the throttle body resoldered.
Hack stock standrad original fuel pump as well.
Has to be fuel I reckon. The injectors were also cleaned a while ago.
Yes feels like it is not getting enough fuel.

 

[cisco]

Cool.

Going to test the voltage readouts from the white car's o2 sensor today. Have a feeling that's the culprit.

Also it has a small leak in the left-most runner of the extractors, which means it could also be sucking in a fraction of oxygen, which tells the o2 sensors its running too lean, which makes it more rich and floods it.

All kinds of possibilities!

 

[CMF_micra-man]

Can you borrow someone's o2 sensor and swap it with yours to confirm that it the problem!

 

[cisco]

Yeah, if blue monster's is the same type, I'll give that a go.

About to get stuck into it..

Apart from that, I'll be reading its voltage readings with my multimeter hooked up to its wires.

 

[CMF_kneival]

Do you have a laptop and consult cable? Probably the easier way to fault find that o2 sensor.

Might also be worth checking to see if the fuel pump is getting full voltage, might be some resistance in the contacts or wiring dropping the voltage to it? Esp during cranking maybe.

The leak in the headers will really screw with the 02 sensor!

 

[CMF_fred]

it probably is 02 sensor but what the about the idle motor?

 

[cisco]

Got out there today and checked out the oxygen sensor's voltage readings.

Seems to be healthy to me. At a constant 2000rpm, it fluctuates nicely between around 0.2 and 0.8v smoothly alternating at a constant rate which is what its meant to do.

At idle, it always seemed to sit on 0.11v though, which means it thought it was constantly lean at idle, which means it should be trying to dump in constantly more fuel at idle. Perhaps that is not what its meant to read at idle..? I'm trying to find information on what o2 sensors should read at idle.. But as one of my other symptoms was a poor idle *sometimes* it could be related.

But hmm anyway, I think the o2 sensor seems fine based on its readings and activity.. Perhaps something else!

There are a whole series of setp-by-step sensor tests in the nissan workshop manual. I think I will just gradually step through all the tests one by one and hope I find something unusual.

 

[CMF_Alex_B]

yeah mine goes really low voltage at idle cisco, seemed odd to me too. but mine dosn't have any starting issues, ever,

Alex

 

[cisco]

Ahh cool thanks Alex.

Ok onto checking the other sensors and stuff then I think.

Also: about the small leak in extractor runner number 1.
I noticed that the O2 sensor is mounted only downstream of runners 2 and 3. I.e. in the one of the "2" sections of the 4-2-1 design. So runner #1 shouldn't be affecting it at all.

 

[CMF_nz_aj]

Rather than dry joints on the MAF circuit boards, have you given the interconnector a wiggle. Symptoms sound very familiar. What happens to the idle when you give the throttle body a whack with the back of a screw driver?
If you go the CONSULT route, you'll be able to see what's going on, i.e.
-airflow & fuel jumping up with no change in throttle position while driving on a level road at constant speed.
-weird/inconsistant airflow readings at idle

I'd suggest that the interconnector is the cause of most MAF problems rather than dry joints. The act of soldering the board is enough of a wiggle to make a difference in many cases.

 

[CMF_evade]

prob fuel pump? Whats the service manual say about diagnosing probs like this?

The old slx had a fuel pump problem and eventually died..it was more instant giving out rather than slowly though

 

[cisco]

Recently, I removed the old adjustable fuel pressure regulator and fuel rail.

It was running very rich for a long time with that setup.

I think what could have also happened is that the rich mixture has clogged up a number of things. Perhaps injectors are covered in rich crap, perhaps the O2 sensor is. etc etc

Also forgot to add another symptom I'm still getting. Car is pumping out black rubbish out the exhaust which is settling all over the rear of the car. It was doing this when I had the adjustable regulator in, but now with it removed and having washed the car, its still doing it continuously!

 

[CMF_nz_aj]

Black soot = way too much fuel.
Is your fuel pressure correct?

Really sounding like AFM.....

 

[cisco]

I don't have a gauge that I can use to measure the fuel pressure with. But I have another spare factory fuel pressure regulator that I could try.

Evade: that fuel reg that came with your rail.. That was never kinked or anything was it? It looks fine, just trying to eliminate everything..

Its really getting quite expensive in terms of the amount of petrol we are having to put through this car, its chewing it up like crazy. Hence the black soot yeah.

Ran out of time today, but tomorrow I will have a look at the spark plugs, try to test the Air Flow Meter and whatever else I can do.

 

[cisco]

Ok..

Spark plugs had a moderate amount of carbon deposits, but nothing EXTREME. Anyway cleaned them up and re-set the gaps. They actually seemed WAY OFF.

That didn't improve anything.

Then I unplugged the oxygen sensor and went for a drive.
Obviously, didn't improve the starting problems and idle quality, but oxygen sensors are ignored during starting and idle - so as expected. Now left it unplugged to drive the car tomorrow and see if the fuel economy changes or gets any worse.

Then I followed a diagnosis test and procedure in the nissan workshop manual.. Unplugged the throttle position sensor and started the car, and the car almost stalls and really screws up badly, can hardly idle.. Then it said to adjust the hidden idle screw while that is unplugged - that's the correct way that you set the idle apparently..

The idle was way off, so adjusted it to approx 650rpm and got it idling nicely like that. Then plugged the throttle sensor back in, and re-started the car back up. Now starts perfectly and auto adjust itself back down to around 650-700rpm. Let the car cool down for a while, then tried repeated starts. Now seems to start perfectly every time. That's weird.. That has seemed to fix that problem.

Also think I noticed that one of the skinny vacumm lines that goes from under the airbox over to the engine temperature sensor seemed to be unplugged. Probably my fault, weird, but anyway, its plugged back in now. Not sure if this would make much difference??

But I'm sure its just a coincidence or another problem.. Because that would have nothing to do with fuel economy.

But anyway, she starts great now. But sure fuel economy is still terrible..

So anyway, keeping an eye on things with the o2 sensor unplugged tomorrow and will go from there.

Next will be to test the AAC valve and the AFM voltage outputs.

Anyway, have eliminated and tested a whole pile of things, also saw no injectors leaks or anything like that.

So I guess, in any case, am narrowing it down further and further every day.

 

[CMF_evade]

Hrmm nope thee fuel rail should be fine..No kinks or anything

If the car was leaking vacuum then it could have had some sorta effect..my car idles CRAP if i have a hose unplugged.

Not to mention it leans out something shocking..but thats the opposite of your prob and its only because of my map sensor.

how bad is it running? How many KMs you getting to a tank?

 

[CMF_Yom]

What type of fuel do you use in it?

Charlotte spits out black carbon deposits when she feeds on Shell Optimax. Also idles very rich and very strong smell of unburnt fuel.

When i feed her on BP Ultimate, the black soot out the rear only happens on high rpm gearchanges (as can be expected), idles much smoother, usees less fuel and the exhaust fumes have very little fuel smell about them. According to consult it also idles more on the lean side than it does rich.

Might be something to look at cisco!

 

[CMF_evade]

yeah optimax is arse. I used that with my previous ecu and my car was pinging its arse off.

only ever use bp ultimate or mobil 8000 now.

 

[CMF_micra-man]

You folk may be interested in this article from the UK TV show 5th Gear.

http://fifthgear.five.tv/jsp/5gmain.jsp?lnk=601&featureid=143

European fuel manufacturing must be of a higher quality standard than Australia?

I would guess from the Clio results a higher octane fuel would not make any measurable difference to a standard Micra.

I guess it depends on how clever your ECU is and if it has a knock sensor setting that is capable of retarding the timing should the engine detect detonation and advancing timing at higher revs to just below detonation.

I'm sure there would be a measurable difference for you guys with programmable ECUs and turbos.

 

[CMF_micra-man]

And this article may also be of interest.

http://theserviceadvisor.com/octane.htm

 

[CMF_Toma]

Thats pretty interesting...

But i get better economy (maybe an extra 50km/tank) when i use Premium stuff like Caltex Vortex and BP Ultimate. So far i get 500km/~35l = 7l/100km
Anyone else?

 

[CMF_Yom]

Yes micra-man our basic 91/92RON unleaded fuels do not have to meet the same quality standards as European fuel.

Heck, Leaded fuel was only discontinued very recently.

This should change over the next few years as the government finally tightens up emissions laws.

 

[CMF_Toma]

And introduces more ethanol... on that note, is ethanol going to hurt our Micras?

 

[CMF_Yom]

In the legal amounts some fuel has, No it won't do a thing. Might clean the system out a little bit though.

Doesnt mean I'll use it though. Yuck.

 

[cisco]

Drove around all day today with the oxygen sensor unplugged.

Car seems identical, still has terrible fuel consumption.

So that would make you think that the oxygen sensor would be broken.. But weird because it seemed to give healthy voltage readouts..

 

[CMF_micra-man]

Borrow a suitable 02 sensor and drive around for an hour or two, to see if the problem goes away.

There must be one other Micra owner in the ACT that can help you out.