2 questions - Patrol and snow , Prado Injectors
Submitted: Thursday, Sep 09, 2010 at 19:51
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Begaboy
hi guys - 2 questions -- came back from Perisher the other week , and anyone that knows the drive back , its a LONG downhill slope for about 5 km + Before we left the car
park ( at the snow ) i let the Patrol warm up till temp gauge moved of dead cold. Now after coasting down the big
hill for a few KM the temp went back to dead cold and car was sputtering like a diesel with 1 or 2 dodgey glow plugs in a dead cold engine ( and unburnt diesel was seen from back of car ) now the Patrol is a 99 model 4.2 TDI - Do the glow plugs automatically come on once engine temperature DROPS ( rather than when ignition is first turned on ) is there a way to prevent this issue such as cover radiator intake partially to restrict air flow?
Second question - wifes forbie is a 2003 prado petrol / Gas -- car has about 300 k on it .. and previous owner ONLY ever ran it on gas - so when i go to petrol it runs like a dog - no power - have tried a few bottles of injector cleaner - made no difference - now should i just bite the bullet and buy new injectors and if they are they plug and play ?
I have had injectors cleaned on other vehicles in the past with only a 70% flow rate after done and charged a fortune - and are after market injectors available rather than genuine ( don't want to have to mortgage the house to buy them )
your thoughts ?
Reply By: PradOz - Thursday, Sep 09, 2010 at 20:54
Thursday, Sep 09, 2010 at 20:54
HI - i have a prado a couple years older than yours with petrol/gas on it. I would suggest you take it into a reputable LPG mechanic for a decent tune up. Maybe its been let go or tuned really lean to gas. I only had dramas on gas when i blew the air box up 3 times so it ran real rough. I then replaced the leads and plugs to suit advice i received from Ice Ignitions in
Melbourne - and since then all great. When i decide to run on petrol it still runs ok so I dont see why it would run that bad on petrol. Maybe a mechanic will find what the previous owner has done to it. Perhaps he let
tank go dry and
tank needs a good clean out??
AnswerID:
429794
Follow Up By: PradoMad - Friday, Sep 10, 2010 at 00:13
Friday, Sep 10, 2010 at 00:13
I have a 99 Prado petrol/gas and it runs beautifully. You need to have that checked out by recognised LPG specialist.
JS
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Follow Up By: Begaboy - Friday, Sep 10, 2010 at 16:00
Friday, Sep 10, 2010 at 16:00
I do know of the backfire issue with LPG , what i am surprised about it the fact when LPG cars are made/ modified they use clips for the air box rather than a spring - the spring would allow the expanding gas to escape on backfire rather than blow up the air box and blow pipes off ....
Just a thought for any LPG installers ...
FollowupID:
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Follow Up By: Begaboy - Friday, Sep 10, 2010 at 16:10
Friday, Sep 10, 2010 at 16:10
Should have mentioned the car runs PERFECT on LPG , runs terrible on Petrol ( like injectors are partially blocked )
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Reply By: Bazooka - Thursday, Sep 09, 2010 at 22:17
Thursday, Sep 09, 2010 at 22:17
Begaboy - I'm no expert but I used to drive an MQ diesel Patrol SD33 engine back in the 90s so I'll pass on my experience in case it helps. Your fuel system may be somewhat different but basically it should be similar. The glow plugs are only to get the egine to kick over, high compression of the fuel/air mix then keeps the it firing (no further spark neded).
Smoke from diesels can have a variety of causes - most related to the fuel or injectors. In winter in the alps service stations stock winter mix diesel which from memory has a lower 'wax' content. If you didn't have winter mix it is quite possible (likely) your injectors may have waxed up a little. Alternatively you may have had slightly 'dirty' fuel - if you run a CAV fuel filter with a glass bowl you will be amazed at how dirty it can get and and how much
water you can drain off. Diesel may be better quality now, wouldn't know.
Wrt a radiator blind - the MQ radiator was huge/super efficient and I used to run a home made blind which covered the top half for most of the
Canberra winter - only for short trips around town or when in the Snowies etc. Temp guage never moved above its normal position but engine always got to operating temp much quicker, as you would expect.
Hope this is useful..
AnswerID:
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Follow Up By: Begaboy - Friday, Sep 10, 2010 at 16:07
Friday, Sep 10, 2010 at 16:07
Hello Bazooka - I should clarify --- i did add fuel additive before i went to alpine region to specifications on bottle ( for below 0 climate ) the unburnt fuel i seen out the car was ONLY whilst coasting down the 5 km long
hill - the car does not blow any smoke when driving - and even when hard on the noise peddle it only blows very small amount of black smoke for very short time - hardly noticeable ?
I often check fuel filters ( with each oil change ) and usually all comes up clean.
Thanks for your reply , was appreciated!
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Reply By: skmaint - Thursday, Sep 09, 2010 at 22:42
Thursday, Sep 09, 2010 at 22:42
Hi Begaboy,
By the sounds of your Patrol it seems like the thermostat could be stuck open. The thermostat should remain closed until the engine reaches operating temp. approx 80deg c. With the vehicle just sitting there it would warm up slightly but once you start moving and the cold air passes through the radiator and thermostat open it would cool down very quickly. Covering a section of the radiator does help, even with a good radiator and thermostat. We always done this in Tassie in the cold. But a new thermostat might be worth looking at.
The glow plugs only work on cold start up.
As for the Prado... sorry I am a Diesel Fitter, I hate petrol engines....sorry. But as the others said may just need a good clean and tune.
Hope this info helps
Cheers
Simon.
AnswerID:
429811
Reply By: TTD - Thursday, Sep 09, 2010 at 22:43
Thursday, Sep 09, 2010 at 22:43
Begaboy
I had a GQ 4.2 and it did over 500,000K and 7 years up and back to the snow and only ever had trouble once with the diesel freezing. Cure a litre of kerosene in the
tank every fill or the Winter mix diesel at the foot of the mountains.
On every trip up the mountains as soon as I got over 1200mtrs she would start to smoke like hell. One of the mountain workers told me that all the vehicles on the mountain smoked because the air fuel mix changed because of altitude and air being thinner above 1200mtrs the engine ran much richer.
With your Prado only ever run on gas it needs a tune to petrol,the injectors should be Ok as LPG is a super clean fuel, you should see that in the oil colour.
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Reply By: Member - Toyocrusa (NSW) - Friday, Sep 10, 2010 at 06:35
Friday, Sep 10, 2010 at 06:35
Hi Begaboy. In regards to your Prado it does sound like the fuel injectors have become carboned over from lack of use. They should be able to be cleaned. They would need to be removed from the engine, dismantled and cleaned in an injector cleaning machine that runs a solution and cleans them ultrasonically. It can also flow test and leak test them as
well. I do them this way at my work
shop and can assure you it is the only way to test and clean them so they come back to original.
The patrol, as others have said, sounds like the thermostat is stuck partially or more open. Regards, Bob
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Reply By: Member - dave e (QLD) - Friday, Sep 10, 2010 at 06:58
Friday, Sep 10, 2010 at 06:58
begaboy,like everyone else said,the patrol has got a stuck thermostat or doesnt have one at all,i owned my pajero for 3 years and it wasnt till i came down from snowys that i realised there was a thermostat problem,it went stone cold from hot and ran like a piece of crap,ran like normal till then,found that the previous owner had removed it for some reason ,$20 later its all fixed
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Reply By: Ray - Friday, Sep 10, 2010 at 07:46
Friday, Sep 10, 2010 at 07:46
I read once that a railway over the Andes decided to modernise from steam engines to diesel and found that they needed diesels of twice the horse power to do the same job at the high altitudes so it would appear that diesel engines do not like high altitudes. I would imagine that petrol engines could have the same problems.
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Reply By: Dave(NSW) - Friday, Sep 10, 2010 at 08:44
Friday, Sep 10, 2010 at 08:44
Begaboy,
If you fueled up before getting to the Alpine area it will be your fuel waxing up, You need to run winter mix up in that area.
Cheers Dave..
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Reply By: Kimba10 - Friday, Sep 10, 2010 at 08:59
Friday, Sep 10, 2010 at 08:59
The patrol would be as described above, the injectors on the prado would be from lack of use and as described a bove the best way is to remove them and have them done proffresionaly cleaned....................03 is it the last of the 90 series or is it the 1st of the 120 series ??
AnswerID:
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Reply By: dublediff - Friday, Sep 10, 2010 at 11:57
Friday, Sep 10, 2010 at 11:57
I would check the fuel pump and maybe flush the
tank and a change of fuel filter in the prado. the fuel goes off after a while and destroys the fuel pump....this happened to my fathers falcon which has been on gas for many years.
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Reply By: roberttbruce - Friday, Sep 10, 2010 at 19:42
Friday, Sep 10, 2010 at 19:42
maybe its been tuned for gas entirely, cams. plugs, timing etc...
check the plugs, if they may are one point colder that would be a big hint
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Reply By: PradOz - Friday, Sep 10, 2010 at 20:33
Friday, Sep 10, 2010 at 20:33
Hi again - have you cleaned the air flow sensor? If not grab some purpose made cleaner (not wd40 etc) at repco etc, remove the 2 screws on sensor and remove and clean as per instructions. I just remembered I had same type symptoms years back when still only petrol (no LPG fitted then) My mechanic back then thought the symptoms meant similar problems as you suggested. He did tests on sensor which came up as being ok which threw him. He even had Toyota look into it with no luck. It was only when a Toyota mechanic kept saying it sounds so much like a air flow sensor failure that they decided to swap it anyway and bingo all fixed. Thats after new injetcor fitted etc too. To my understanding the sensor has minimal impact when on LPG but will effect you on petrol. Its so easy to
check and clean, and for about $15 for cleaner at Repco worth trying maybe, just follow instructions re starting car afterwards - good luck
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