vapor lock? hesitating '94 eclipse

the problem can never be reproduced at will. how do you suggest determing no spark or no fuel on the side of the road? anything i can do? everything gets ruled out because 'if it were faulty, it would always be faulty, not just sometimes'...

Sounds like an ignition module problem to me. Modules will get hot quickly and quit firing and once they cool, they will work again, until it quits working all together.

I also wouldn't rule out the fuel pump, it may be going bad. A friend of mine had the same problem with his RS Camaro. The next time you go to drive it, take a rubber mallet or something you can hit the bottom side of the gas tank (around where the fuel pump should be, usually in the center) without damaging it and see if it will crank. If it does, fuel pump. Also, if there is a fuel pressure test valve, you can push it with a screwdriver to see if there is pressure, some may come out but it should spray out with force under pressure. It would be safer to use a gauge of course, but you said you wanted an on the side of the road diagnosis.

Question: What does it feel like when it dies, running out of gas dying or it just stalls?

Spark is easy enough: remove a plug wire, stick a screwdriver in it, lay the contraption near some metal, crank the engine, watch for spark. OR, remove wire from coil or cap and attach an ordinary piece of wire, run the other end of wire near metal, crank engine, watch for spark. Fuel: most vehicles have a fuel schrader valve. Push it and see if fuel readily squirts out under pressure. Doing the fuel and spark test at the same time is a very bad idea. Doing the spark test after the fuel test is also a very bad idea.

why would it stall in the first place, though, and hesitate? if i understand correctly, what you are describing is only an ignition problem.

Had the same problem with two different toyotas. Drove me, my independent mechanic and the local Toyota dealer crazy on the first car.

I ended up replacing the carbureutor to no avail. Turns out it was the ignition coil was getting weak. Worked fine if there was no water moisture, but as if it was damp, the engine would heat up or something and there was enough steam under the hood to make it act up about a mile down the road after a cold start.

Eventually, it go so it was hard to start. I'd check the coil and make sure it is operating properly. Unless you expect a dry spring....

ok i meant, i replaced the cap and rotor about 3 months ago, the symptoms still persist. by "whole thing" i meant the entire distributor, as opposed to only the cap and rotor. thanks for your explanation of the coil and such, i guess im still waiting on the car to have problems again so i can first determine if its even lack of spark.

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No I don't think you would need to do that. Depending on your vehicle, there are so many vintage technologies still around it is impossible for me to -know- what is in/on each engine anymore, never mind by model, but even YEAR, as time marches on.

Actually that is quite simple to do, believe it or not. You can buy a little test device at an auto parts store that uses the electromagnetic field around each plug wire as a source of energy to drive a Light emitting diode *aka LED*

It is a good idea to keep in mind there is enough hi voltage in those wires to send your heart into a tailspin and knock you off your feet. When using a device such as this, you would be advised to attach it to an insulated rod of some kind. Glass is a good insulator, so is rubber, some plastics.

Then you can just hold this little led glow plug next to each wire and verify that it is taking a full charge to the plugs each time it illuminates. do this for each wire, and your question is answered.

You will notice it will fire each wire during one revolution of the rotor/reluctor in the distributor. If you find a dead wire, then suspect the _wire_ before assuming anything else is bad. You can measure the resistance of the wires with an ohm meter. They usually have a carbon thread going down the middle of them to cut down on spurious pulse radio frequency emissions which would interefere with many communications devices, so the wires are rather fragile in that respect. No sharp bends. Handle with caution, and NEVER TOUCH THEM while the engine is running. ever.

But you will see in less than 60 seconds if all your wires are firing with this little light. It isn't easy to see in bright sunlight, so dusk is a good time to do this, and use a flashlight to guide you from wire to wire.

Again, hands away from the dang wires. And wear rubber soled shoes/boots when doing this. And keep one hand in your pocket at all times, IOW don't use your free hand to lean on the car body.

We're talking a LOT of volts here, enough to knock you to the ground, and if your heart is in less than perfect shape, well, let's not go there.

Lg

"fusquanto" wrote: > I have a 1994 Mitsubishi Eclipse 1.8L, 120,000 miles. After I > drive it for > about a minute, the car will start hesitating, and when i get > to a red light, it > stalls out. After it stalls out, the car will not turn back > on, it will > crank, but not start. After 15 minutes, the car starts up > again with > absolutely no problems and is good to go. I've taken it to > two Mitsubishi > dealers and they recreate the problem, but have not been able > to diagnose it. > All belts, fuel filter, pcv valve, plugs, wires, distributor > cap, and rotor have > been replaced. The dealerships ruled out the fuel pump as > being the problem. > The computer is not throwing out any codes. Fuel injector > pressure was checked > as well. After replacing the PCV valve, the problem was gone > for 3-4 weeks, but > today it came back. The car has no EGR valve. > > A guy at Midas told me I may have a "vapor lock" problem, but > I dont > know anything about that. He said the fuel line is heating up > fast while the > engine is still cold, creating vapors in the lines that block > the fuel from > pumping through, and after it stalls and I let it sit for 15 > minutes, the > temperatures equalize and the car is good to go again... He > asked me if I had > replaced any parts from the fuel system (like aftermarket > modifications), but I > have not, everything is stock. > > Anyone have any clue what this may be? please help! thanks

if you are still having trouble, you may want to focus on three items.

1. the ecm, if not repaired or replaced already, will have to be replaced sooner or later. reason - defective capacitors in the ecm will have gone bad, and leak acid that will ruin the ckt board and other parts that it touches see this site for more info:
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   the caps (three i think, maybe two...) you will have to buy are easy to find, but not "generic" - make sure they are a "lo-esr" cap.

1. the airflow sensor - located inside the air duct from the front of the car. check the voltages up until the failure mode. try taking the sensor out of the ckt and if possible subsitute a resistor to simulate the sensor.

2. the distributor and/or coil. bad coil should be easy to diagnose. if it?s the pick-up in distributor will mean a 9 fix from your local advance auto parts