We Need a Tow! 1999 Supra dieing

So my father in law has a 1999 Supra that will run awesome for a couple hours and out of the blue it will just die. Over the past two summers the family will take the Supra out and cruise around ski go to the sand bar till she decides to shut off. Father in law and I took it out this weekend drove around for 30 minutes ranging from idle to 30mph and never had the first problem. We brought it back put it on the lift went in and packed cooler for day on the lake. Came back a couple hours later fired the boat up idled for about 300 yards and the Supra started to sputter and just died. This has happened several time the last two summers. When the engine dies it will not start for an hour or so. We can literally tow it home put it on the lift for an hour come out and it will fire up and sound just fine. When the engine dies the radio and dashboard lights CD player etc will stay on. We do not think itÂ’s an electrical issue but we are not sure. Any help would be greatly appreciated.

Need more info:Carburetor or fuel injected?
When it dies, does it crank over without issue?
Mechanical fuel pump or electric?
Also, dash lights, radio, etc. will stay on as long as the ignition switch is in the run position.
How long has he owned it, and what maintenance does he do?

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Originally Posted by secondsupra2004

Need more info:Carburetor or fuel injected?
When it dies, does it crank over without issue?
Mechanical fuel pump or electric?
Also, dash lights, radio, etc. will stay on as long as the ignition switch is in the run position.
How long has he owned it, and what maintenance does he do?

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It is a 1999 Supra Comp. I’m guessing it was the Indmar Assault engine so it would be carburetor. It was the base package Supra at the time but I’m not a 100%. The engine turns over but doesn’t seem to be getting fuel. He has had it for almost 20 years i think he just does the basic maintenance on it. It doesn’t get abused by any means just a couple hours every other weekend in the summer. He’s had it looked at before and they never can put a finger on the problem. Like i said one day it’ll be just fine and the next it will quit on him for awhile then fire right back up. I had seen where some people talk about vapor lock or debris in the gas tank. I am by no means a gear head but it always seems likes the gas gets shut off. I really appreciate the quick feed back.

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Originally Posted by [email protected]

It is a 1999 Supra Comp. I’m guessing it was the Indmar Assault engine so it would be carburetor. It was the base package Supra at the time but I’m not a 100%. The engine turns over but doesn’t seem to be getting fuel. He has had it for almost 20 years i think he just does the basic maintenance on it. It doesn’t get abused by any means just a couple hours every other weekend in the summer. He’s had it looked at before and they never can put a finger on the problem. Like i said one day it’ll be just fine and the next it will quit on him for awhile then fire right back up. I had seen where some people talk about vapor lock or debris in the gas tank. I am by no means a gear head but it always seems likes the gas gets shut off. I really appreciate the quick feed back.

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Vapor lock can be an issue. I would warm it up good around the lake, then bring it back near your dock and shut it off. Open the engine hatch and remove the spark arrestor. Look down in the carb and see if any fuel is dripping into the venturis. If it is, then its flooding when it gets hot. See if it starts right up. If not, without the engine running, advance the throttle and see if fuel is sprayed into the carb. If not, then you have a fuel supply issue. Vapor lock, blockage in the fuel lines or tank, or pump going bad.
Remember, you need fuel, spark, air and compression to make the engine fire. Check fuel first, then you can pull a spark plug and see if you are getting spark.
A friend of mine had a similar issue years ago and it would be the pickup coil in the distributor. It would run fine, then if you stopped for a little while it wouldn't start. Eventually after sitting, it would start but he could never figure out what it was. Eventually the pickup coil went bad and thats when he found it.

Quote:

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Originally Posted by secondsupra2004

Vapor lock can be an issue. I would warm it up good around the lake, then bring it back near your dock and shut it off. Open the engine hatch and remove the spark arrestor. Look down in the carb and see if any fuel is dripping into the venturis. If it is, then its flooding when it gets hot. See if it starts right up. If not, without the engine running, advance the throttle and see if fuel is sprayed into the carb. If not, then you have a fuel supply issue. Vapor lock, blockage in the fuel lines or tank, or pump going bad.
Remember, you need fuel, spark, air and compression to make the engine fire. Check fuel first, then you can pull a spark plug and see if you are getting spark.
A friend of mine had a similar issue years ago and it would be the pickup coil in the distributor. It would run fine, then if you stopped for a little while it wouldn't start. Eventually after sitting, it would start but he could never figure out what it was. Eventually the pickup coil went bad and thats when he found it.

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AWESOME feed back thank you! Do you know of any good YouTube videos that show someone working on this sort of Supra problem? Going send you a couple other questions. Say it’s the indmar assault mpi engine. What would you be looking for if it was fuel injected rather than carburetor. I had read that if it vapor lock once it happens to pop the engine cover and try to look at the lines to see if there is any fuel in them. Father in law said he had taken it to get looked at not sure if they rode it long enough to see it happen first hand. If it was a crimped line you’d think you’d be able to see it.

Without knowing the correct fuel system setup, I'm just guessing. You cannot see the fuel through the fuel lines. I don't know of any specific YouTube videos on this. Having an intermittent problem like this is always tough to troubleshoot if it comes and goes. You need to check fuel pressure at the schrader valve or fuel rail to see if it has pressure and how much. With MPI, you can't see fuel going through the throttle body either. When it quits, I would check spark first. If you are getting spark, then you can use some spray carb cleaner through the throttle body and it will sputter or try and start if it is lacking fuel. There's no easy answer to this, especially if you don't have the correct tools to diagnose.