Supra4100

Hi everyone. Heres the deal. My car is running horribly. I purchased this car knowing of some sort of problem. When I took delivery of the car it was parked for the previous 2 months. The car ran like a dream. I drove it approximately 150 miles and then it happened. Running rough and puffing white smoke and smell of very strong fuel. I thought the white smoke may have been coolant, but the coolant level is the same. I have gone to the extreme and replaced the head gasket. Cylinders 1,2,3,4 and 6 had your usual carbon buildup but number 5 was clean. Anyhow I replaced the head gasket, put the car back together and drove it the next day. The car ran fine for the first 15 miles and then again white puffs and strong fuel smell. Today I put gas in before work. It filled up to the half mark. In 6 miles time I went down an 1/8th of a tank. Thats allot of damn fuel. Any ideas guys?
Im desperate here.

Any suggestions what so ever

Thanks Ben

Buttercup

I'm assuming you have sc300 (1-6 cylinders)
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I thought gas that goes through exhaust turns black?

Are you sure the car went from 1/2 to 1/8? Maybe you should fill up to full, and drive until needles goes to half, and then fill up again.
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I have a similar problem. The vehicle runs rough during start up for 20 seconds though, but the white smoke lasts for 10 minutes in 50 degree weather. However I look at other old cars and they have the same 10 foot trail of smoke under acceleration. It smells coolant-ish and my cold coolant level dropped 500mL in 2 weeks.

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I would check the fuel lines. They are on the driver's underside. Check for cracks and such. I changed my fuel filter a few days ago and the problem I have is less severe.

You could also try taking off the wall in the trunk that leads to the fuel tank. There's 5 or so clips on the wall and sooner or later you'll get it off.

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O. L. T.

iTrader: (17)

wow, thats bad to go through a head gasket change and come up empty handed. check your fuel pump ecu and all your related sensors. good luck!

Supra4100

one thing that is kind of weird is that the extra fuel is localized in cyl 5. Well I unplugged that injector and it still blows white raw fuel smoke. I have a spare 2jz sittng in my garage. I thought about swapping parts, but figured it was a lost cause.

95SC400

My car suddenly had this exact problem a while back and I replaced the spark plug wires/harness and the problem was solved. But of course this may/may not be the same cause for what you are encountering. Symptoms could be caused by a lot of things i suppose.

Anyway... hope maybe that helps.

Supra4100

Yeah I put a new bug cap and wire and even plugs. I was thinking that, but it wouldnt explain why my fuel economy went to about 3 gallons of gas in 5 miles.

97LS400

Supra410

White smoke (after the car warms up) is caused by coolant leaking in to the cylinder. Second clue is that your #5 cylinder was really clean... water in the cylinder will remove all the carbon whereas extra gas will make it worse. If you could drive it enough, the dropping coolant level would be final proof.

Most likely cause of the coolant leak (since you have already replaced the cylinder gasket) is a crack in the head allowing coolant in to that cylinder. You can run a pressure test on the head in question to be sure but it might be cheaper to just get a pair of rebuilt heads.

You would know immediately if that much fuel was running through the cylinder(s) because it sounds like popcorn popping when the unspent fuel hits the catalytic converter. Look for another cause on the missing gas. Buttercup suggested checking fuel lines, that was a good idea. You can leave the car idling and check for leaks. Certainly don't drive it until you pin down where the missing fuel is going.

Good luck...

Pen

Are you talking white smoke or steam? The "white smoke" on startup is usually just steam, it dissipates to nothing if you watch it.

Supra4100

I realize the whole steam bit. A really rich af mixture will give black smoke, not white. But when you have too much unburnt fuel going through it will be white. The car will run fine for a while and then suddenly start running rough. Infact the car will run fine for awhile and then start running rough and puffing white smoke. I yanked the o2 sensors for a visual. Cyls 1-3 was dry, but 4-6 was soaked in fuel. My fuel economy will be fine and when this starts up it dramaticly drops. No fuel leaks whatsoever anywhere. The only time I smell a strong fuel odor is when the car starts smoking. Worse comes to worse If i find it's not an elcrical problem I do have a spare 2jzge to drop in.

Supra4100

oh yeah, no loss of coolant here.

aliga

iTrader: (147)

maybe one of the o2 sensors is defective, try to swap them and see if the currently ok bank runs rich after the swap.

HD-GS4

You could also try replacing the PCV valve. It's a $2 part, and only takes a couple minutes to replace. It would eliminate that from being the problem, and probably needs to be changed anyway...

Supra4100

Yeah its been replaced a couple of months ago, Allot of stuff on the car is new timing belt ignition components etc etc.. Just if I could only figure out why theres so much fuel. I hope it isnt the ecu.. I left the exhaust manifolds from my spare engine at work, but I will swap o2 sensors to see if anything happens. I need to crack open the manual and just running down the components with a multimeter....

Supra4100

btw. Does anyone know if the 2jzge is equipped with a cold start injector/valve?? I look on the spare engine and the one in the car and I can't find anything that would look like what it is used for. Anyone??

Supra4100

Well after intensive trouble shooting the problem is isolated in cyl 5 With the ignition on I was checking voltages off the ecu. for terminals 10,20,30,40,60 i read 11.5 volts For injector terminal 50 i read a .1 I have cyl 5 disabled no spark or fuel. The car run like its missing a cylinder, but no smoke. So i need an ecu. Trying to find one of the lil boogers but am having a hard time. SO, If anyone has one for a 92 sc300 part number 89661-24310 let me know and a reasonable price for the asking.