Author Topic: TRX is using to much petrol (Read 14906 times)

gach2 · « **on:** Jan 29, 2007, 04:56PM »

I dont know if this is normal, but my TRX is using around 12 litres of petrol for only 60kms.

I drive sensibly and even granny it, by changing gears at 2000 rpm... so is this to much for a trx as there only 2.4 litre engines.

I got the car serviced 2 weeks ago and it has been quickly checked by a mechanic and they really couldnt find the problem.

rathies · « **Reply #1 on:** Jan 29, 2007, 05:14PM »

is it going faster and making farty noises? check for exhaust leaks, my fuel economy was horrendous when i had a couple of leaks. The car went faster though

gach2 · « **Reply #2 on:** Jan 29, 2007, 05:23PM »

the car isnt going faster but it does sumtime make fart noises on take off
but i thought that was normal as its been there 4 a while
ill check the exhaust nyway

Kranzy · « **Reply #3 on:** Jan 29, 2007, 08:18PM »

coolant temperature sensor will be a thing to check. If its giving cold readings to the ecu then the ecu will make the car run very rich.

Car running very rich = using far too much fuel.

gach2 · « **Reply #4 on:** Jan 29, 2007, 08:49PM »

sorry but i have no idea how to check that
and would a new ecu chip help as i am thinking of getting an antrx chip for it but other than that i have no idea how to check the temp sensor

Kranzy · « **Reply #5 on:** Jan 29, 2007, 08:51PM »

Buy a new one, should only set you back about $50.

You can test the resistance of it at certain temperatures but its easier to just replace it.

A chip will help, but not much if your getting incorrect readings from a sensor as the ecu will adjust it anyway.

Budgie · « **Reply #6 on:** Jan 29, 2007, 09:48PM »

Check your injectors as well...

Mine are leaking on my TRX, I have done about 450km to a tank (almost dead on the empty line now).

They were not leaking a week or so ago, but have just now decided to give me the shits!

xxxx · « **Reply #7 on:** Jan 30, 2007, 12:41AM »

yeah leaking injectors waste alot of fuel and i should know, they have been leaking since ive had the car and id say im getting about 12l per 100kms compared to the 10l per 100kms i should be getting!

KNG P1N · « **Reply #8 on:** Jan 31, 2007, 08:30PM »

how can you check them though?

Kranzy · « **Reply #9 on:** Jan 31, 2007, 08:46PM »

With injectors from what i remember worst case is you can physically see them leaking, or if there leaking internally you get a smell of petrol in the engine bay when the car is off and its usually more difficult to start because the engine is basically flooded, depending how long the car is off and how bad the injectors are leaking.

xxxx · « **Reply #10 on:** Jan 31, 2007, 10:32PM »

i can actually see mine leaking. As soon as i switch the car off there is dripping from the base of the injectors onto the intake manifold for about 3-4 seconds? who knows how much it leaks while im driving! ive never had any problems with flooding or starting though, my car usually starts in less then 1 crank.

Budgie · « **Reply #11 on:** Feb 1, 2007, 06:39AM »

Changing my leaking ones with four good ones today xxxx... fuel econ should be perfect after this, I will let you guys know.

chr1S · « **Reply #12 on:** Feb 1, 2007, 07:06AM »

Is your o2 sensor connected ?

SSS · « **Reply #13 on:** Feb 1, 2007, 08:40AM »

Replace your thermostat too.
If it is stuck open, the car does not get a chance to get upto temp no matter how long you let it warm up for, and therefore the ECU will compensate with more fuel.

I would do this before changing the coolant temp sensor.

dave-trx · « **Reply #14 on:** Feb 1, 2007, 07:27PM »

Go through and check everything. Check your leads with a multimetre, check your plugs (colour of the electrode will tell you the condition of your motor)

Check the rotor button and distibutor cap. Pull out the rotor button and rub the electrode of the rotor on sand paper until the metal strip is shiny. Clean the white shit of the conductors in the dizzy cap.

Pull out the air filter and clean it by bashing on a old white rag on concrete. That will show all the shit that comes out.

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Check your injectors as well...

Good point Budgie

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coolant temperature sensor will be a thing to check.

Courtesey of Kranzy

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Is your o2 sensor connected ?

Courtesey of chris.

All these things should see your car up to standards.

Good luck

Budgie · « **Reply #15 on:** Feb 2, 2007, 10:39AM »

I have swapped my injectors over as of yesterday.

Fuel economy is better and so is low RPM driveability. Its still a little off I think however.

When I start it from cold, it will idle at 1400rpm or so (cold start) then go down and settle no lower than 1000rpm. I know the AAC valve is stuffed, so I'm swapping that today, but the car almost never reaches the middle of the guage temp-wise and will stay in the first quarter almost all the time, until your stationary.

SSS · « **Reply #16 on:** Feb 2, 2007, 11:05AM »

Same. Not sure if it's (another) thermostat problem or not.

xxxx · « **Reply #17 on:** Feb 2, 2007, 05:02PM »

heh budge our cars sound so similar with problems/wierd things in so many ways! lol u got gearbox problems too?

dave-trx · « **Reply #18 on:** Feb 2, 2007, 11:21PM »

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but the car almost never reaches the middle of the guage temp-wise and will stay in the first quarter almost all the time, until your stationary.

I think this is normal. Think about it. These cars motor's are east west. No mechanical fan constantly going. The electric fans only works when stationary or low speeds. Also when the A/C is on.

Dont worry budgie and SSS mine has always done it.

By the way budge money order posted today.

chr1S · « **Reply #19 on:** Feb 3, 2007, 12:34PM »

Mine also sits between C and bottom dot, I'd rather it work there anyway, it feels to go better.

Budgie · « **Reply #20 on:** Feb 3, 2007, 09:48PM »

Dave. My bluebird temp guage goes up as your drive it after a cold start (slowly) then stops at half.

It stays at half all the time.

I started the TRX and drove it about 2km through 60 zones, then out on the highway for 1hr @ 100kmph and the guage was only 1-2mm above the cold line! I don't think thats normal... Also, when I got home I opened the engine bay quickly and could easily hold my hand on the radiator cap. Was not hot at all. The top and bottom rad hoses were hot, but I could still hold them.

I noticed that the exhaust manifold was glowing red underneath its sheild as well... weird as the car was just cruising at 100kmph... does running lean make the manifold get hotter like that?

Its done about 450km to a tank again as well, it tricked it!! Fucking thing!

So possible issues now are-

- Thermostat (i'm pretty sure its ALWAYS open, which is shit)
- ECU temp sensor (thinking its cold, so always running richer... could be a cause & effect issue with the thermostat)
- O2 sensor playing up.

noss · « **Reply #21 on:** Feb 4, 2007, 10:03AM »

budgie, this should be normal for any car (cold at highway cruising) cause think about it, you're driving at high speed, and as the car travels along, not only is plenty of air passing across the radiator, but the hot air is being sucked out of the engine bay by a vacuum like effect of the car as it cruises along the road.

as soon as you stop driving at 100km/hr, and start driving in traffic, the temp will quickly reach its otherwise normal operating temperature.

thats been the way its always been with both my u12's, its entirely normal. dont waste your money trying to fix it.

dave-trx · « **Reply #22 on:** Feb 5, 2007, 09:09AM »

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Dave. My bluebird temp guage goes up as your drive it after a cold start (slowly) then stops at half.

CA18DET in bluebird, KA24E in TRX. Different motor's. These motor's are also in commercial vehicle's. It ain't really working all that hard in a U12.

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I started the TRX and drove it about 2km through 60 zones, then out on the highway for 1hr @ 100kmph and the guage was only 1-2mm above the cold line! I don't think thats normal... Also, when I got home I opened the engine bay quickly and could easily hold my hand on the radiator cap. Was not hot at all. The top and bottom rad hoses were hot, but I could still hold them.

That ain't normal. My TRX will sit on a quarter at 110km/h but first dot around town.

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I noticed that the exhaust manifold was glowing red underneath its shield as well... weird as the car was just cruising at 100kmph... does running lean make the manifold get hotter like that?

That ain't normal. Running lean will do that. Fix it other wise you will have a cracked manifold.

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- Thermostat (i'm pretty sure its ALWAYS open, which is shit)

Get a genuine Nissan one. The aftermarket one's are all shit.

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- ECU temp sensor

Check the harness connector pin's also.

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- O2 sensor playing up

There about $40. Easy fix plus better fuel economy.

Budgie · « **Reply #23 on:** Feb 5, 2007, 09:25AM »

Quote from: noss on Feb 4, 2007, 10:03AM

thats been the way its always been with both my u12's, its entirely normal. dont waste your money trying to fix it.

Yeah, but something is up due to the 450kms im getting from 50 litres.

Quote from: dave-trx on Feb 5, 2007, 09:09AM

That ain't normal. My TRX will sit on a quarter at 110km/h but first dot around town.

I figured as much. This was no-where near a quarter, i mean the needle was only just off the cold line. A bees dick off it.

I will check all my connectors again, but I'm seriously leaning towards the thermostat being stuck open.

SSS · « **Reply #24 on:** Feb 5, 2007, 09:54AM »

It will be budge. Trust me.

Budgie · « **Reply #25 on:** Feb 5, 2007, 09:58AM »

Ok. Well lets assume it is for certain.

Will replacing it help my economy do you reckon adam? Is it possible for the ECU to have been running constantly rich all the way back from bacchus marsh (70ks) because the guage was sitting a millimetre off cold?

Do you have an opinion on the glowing exhaust manifold thing mate?

SSS · « **Reply #26 on:** Feb 5, 2007, 10:12AM »

Quote from: Budgie on Feb 5, 2007, 09:58AM

Ok. Well lets assume it is for certain.

Will replacing it help my economy do you reckon adam? Is it possible for the ECU to have been running constantly rich all the way back from bacchus marsh (70ks) because the guage was sitting a millimetre off cold?

Do you have an opinion on the glowing exhaust manifold thing mate?

When my thermostat was stuck open, it would sit just above cold. Therefore when stopping at a set of lights, the wideband still displayed cold start enrichment as the ecu still thought the car was cold.

Fuel economy improved straight away after i changed it; i got at least another 50k's to a tank.

as for the exhaust manifold glowing, check the ignition timing (or did you already?).

Too retarded timing often results in high EGT's which will make the manifold glow.

Budgie · « **Reply #27 on:** Feb 5, 2007, 10:33AM »

Quote from: SSS on Feb 5, 2007, 10:12AM

When my thermostat was stuck open, it would sit just above cold. Therefore when stopping at a set of lights, the wideband still displayed cold start enrichment as the ecu still thought the car was cold.

Fuel economy improved straight away after i changed it; i got at least another 50k's to a tank.

as for the exhaust manifold glowing, check the ignition timing (or did you already?).

Too retarded timing often results in high EGT's which will make the manifold glow.

Adam, thanks mate. I will go buy a thermostat today.

My timing is set to 15" (right over the line second from the right). The last line on the right is 20" of advance right?

SSS · « **Reply #28 on:** Feb 5, 2007, 10:40AM »

IIRC, yes.

Budgie · « **Reply #29 on:** Feb 5, 2007, 09:06PM »

Thermo was totalled... was original I reckon, really stuffed!

AAC has been changed as of today (looked a little rooted). But the idle is still cactus, sits @ 1000rpm and adjusted the screw on the ACC only make the idle increase (if you wind it out) and it doesn't decrease if you wind it in, stays @ 1000rpm and won't go lower.

When I remove the plug on the AAC valve the idle instantly drops to 650/700rpm however, so doesn't that mean the AAC is working correctly?