Suddenly Stalled!

[couper]

Hi guys, I was driving to the supermarket yesterday and all of a sudden the car shut down (93 SC400). Went to try and start it and it seems to almost fire up again but no luck. The rest of the attempts were hopeless. The car turns over nice and fast so its not alternator or battery problem. Tried to fire it up a few hours later, but still no luck. Car was running fine before that, no warning lights, AC was on also. Have never had any problems like this before.

I checked out the previous posts that all point to the fuel pump ECU. But they all stated that the car would stall, would start up again, and stall again later, or even much later. mine has never had any issues before and just wont fire, could it still be an ECU issue. I was told by a Lexus service advisor that the fuel pumps rarely go on these vehicles. Plugs and PCV were changed 5 months ago, wires were tested for resistance and checked out ok, and I only use premium fuel. Car has less than 150k KM (under 90K miles). Any thoughts would be greatly appreciated.

[lexus082]

Hi guys, I was driving to the supermarket yesterday and all of a sudden the car shut down (93 SC400). Went to try and start it and it seems to almost fire up again but no luck. The rest of the attempts were hopeless. The car turns over nice and fast so its not alternator or battery problem.  Tried to fire it up a few hours later, but still no luck. Car was running fine before that, no warning lights, AC was on also. Have never had any problems like this before.

I checked out the previous posts that all point to the fuel pump ECU. But they all stated that the car would stall, would start up again, and stall again later, or even much later. mine has never had any issues before and just wont fire, could it still be an ECU issue. I was told by a Lexus service advisor that the fuel pumps rarely go on these vehicles.  Plugs and PCV were changed 5 months ago, wires were tested for resistance and checked out ok, and I only use premium fuel. Car has less than 150k KM (under 90K miles). Any thoughts would be greatly appreciated.

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My car suddenly started to act up and it started to stall out while idling and later found out the Mass Air Flow Meter (sensor) was bad. I still was able to drive the car though. Might be worth it to rule that out. Easy to check, just a suggestion. You have to disconnect the connector and the two pins on the far right when connected to an ohm meter at 70F degrees it should read between 2-3k ohms.

[JamesN]

Did you turn OFF the AC then the car stalled?? Cuz if your do its a common thing for our car.

[couper]

Did you turn OFF the AC then the car stalled?? Cuz if your do its a common thing for our car.

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No, the AC was on when it shut down. It just wouldn't start up again and its been 2 days now, turns over fine, just wont start. A freind of mine said it could also be that the timing belt snapped off, but I'm sure I would have felt/heard something if that was the case.

[Sadistic]

I really don't think a fuel pump is something to completely rule out. It could possibly be that. I would also take your timing belt cover off, and give that a look. Just to be sure. Check to see if the car has fuel pressure under the hood. Check to see if the cylinders are firing. If you're going to fix it yourself, you need to start checking into these things. If not, I would just take it to a dealership. It would probably take about 15 minutes to figure out what the problem was.

[cptlinebacker37]

i was having the same problem with my 92 sc300........ i would just be driving down the road and all of the sudden it would stall.. but then after it would sit there over night it would start up again and run for about 10 mins and stall..... i rulled it down to the fuel system and tryed bypassing the fuel pump ecu just because it took only 10 mins..... and since then i have had no problems

[popaige]

I have had the same problems with my 93 sc300. I took it to a shop the 1st time and they said they fuel ecu had been by passed for awhile. They replaced it with a new ecu and about 1000 miles later the car stalled out again. I by passed the fuel ecu and the car started right up. Any idea's what would make the ecu short out? Fuel pump maybe?

Does the sc400 use the same ecu?

[sjc6765]

How do you bypass the ecu?

[popaige]

How do you bypass the ecu?

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The fuel pump can be forced to operate in the high voltage setting by placing a jumper in the engine diagnostics connector between FP and +B terminals (for location of terminals see the label inside the diagnostics connector cover). A straightened up paper clip can be used as a jumper but must be inserted very deep in the terminals. This function is useful for checking that the fuel pump is not faulty (it can be heard running with the ignition on) and also to make the car mobile in case the fuel pump ECU is faulty. We strongly advise against driving the car for prolonged periods with the jumper inserted as the current draw of the pump in its high setting is about 7.3A and the pump may not have been designed to handle the load permanently and may overheat and seize, creating more (expensive) problems. At idle and under light loads the engine may be running rich due to increased fuel pressure.

[don_juan_miami]

It could be all those things, but you want to know waht happened to me? I had just filled up my tank at a gas station and then my car stalled. being in near perfect condition, i was flabbergasted. (wow , did i just say that... im such a nerd...) I realized...oh it could be the gas!... Well i was right. Living in miami, the gas attendant told me i was the 6th person that morning (and it was only 6 am!!! ) that had used premium and the car shut off. He said it usually happens when it rains really hard and water seeps into the tanks of gas underground. Needless to say i got a new engine. Happy hunting

Juancho

[kboogie]

I had a somewhat similar problem with my 92 SC 400. Lexus mechanic that I know replaced my fuel pump ECU and I haven't had the problem since. It wasn't cheap though. He also said this was a common problem for this car.

[couper]

Thanks for all the replys guys. Turns out it wasn't the FP ECU at all. The fuel pump was seized for some odd reason. Replaced the pump and alls well. The odd thing is that most people thought it was most likely the ECU, even the 2 Lexus parts dealers I contacted. But I guess any and all components can give sooner or later. Thanks for all the assistance fellas!