vapor lock? hesitating '94 eclipse

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

Vapor lock is probably not where to look here. Most modern electronic
F.I. systems run enough pressure from the pumps to virtually make this
an impossibility. If properly diagnosed & the headache can be
reproduced at will, you should be able to determine what is lacking at
the time of no start, (no spark or no fuel) , then go from there.
Sounds like you have already experienced the "cap rotor wires" syndrome
& attacked the fuel syst. somewhat but you need to stop blindly
throwing parts at it & attack from an intelligent standpoint. Good
luck.

On 6 Feb 2005 18:40:34 -0800
"pater" > wrote:

> Vapor lock is probably not where to look here. Most modern electronic
> F.I. systems run enough pressure from the pumps to virtually make this
> an impossibility. If properly diagnosed & the headache can be
> reproduced at will, you should be able to determine what is lacking at
> the time of no start, (no spark or no fuel) , then go from there.
> Sounds like you have already experienced the "cap rotor wires" syndrome
> & attacked the fuel syst. somewhat but you need to stop blindly
> throwing parts at it & attack from an intelligent standpoint. Good
> luck.
>

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?

fusQuanto wrote:

> 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'...

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.

On 6 Feb 2005 20:33:17 -0800
"MyStang428CJ" > wrote:

> 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?
>

well today, i drove for 3 minutes, pulled into a store's parking lot, turned the
car off, returned after 5-8 minutes, turned car on, reversed, drove to the
driveway ~30 feet, stepped on the gas to enter the main street and as soon as i
did that the engine shutoff without any warning (no hesitation), but on the way
to the store it had been hestitating very mildly when i was going like 30mph.

most other times it hesitates heavily, ill by flooring the pedal and it will
take a few jolts of hesitating and then finally it will decide to increase RPMs.
then at a red light it will hesitate at idle and stall out. thats when i
usually throw it in neutral to keep the RPMs up, but even when i did that, threw
it back in drive when the light turned green, the car instantly stalled when i
threw it in drive, i didnt take my foot off the gas. i tried turning it back
on, it would crank, but not turn on, i pushed it into a parking lot, waited
15-20 minutes,and it turned back on fine with no incident.

> 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.

Ignition -- ignition module or electronic pick-up is faulty!!!

> 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

vapor lock!-- unless your engine/fuel system has been converted!
NO

Perhaps your computer is faulty!

BBA

"fusQuanto" > wrote in message
news:20050206193355.4cc8463d.fusQuanto@yahooNOSPAM .com...

You either have no spark, no fuel, or both. I'd suspect the MPI relay then
ECU for starters, as these control both.

The ECU is located in the center console behind the radio. Pull it out, open
up the can (4 screws) and have a sniff. If there's a fishy-like smell, or
there's goo leaking out of the large electrolytic capacitors, you need to
replace these caps or get another ECU from a wrecker. Try R+R the ECU
connectors a few times, as this often helps poor connections.

When the fault occurs, switch off the IGN, then back on again. The Check
Engine light should come on for a few seconds then turn off. If this does
not happen, your ECU is not gettting power (most common problem) or its
fried (less common, but see above). The problem may be the MPI relay. This
is a large can (approx 45x30x25mm) near the ECU, with a 2x8 or 2x10
connector. They commonly give up after a few years. One symptom is that
when the car won't start, you get a click from the relay, and thats all. Get
a replacement from a wrecker.

Stewart DIBBS

MyStang428CJ wrote:
> 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?
>
Hasn't the rail pressure been monitored for a couple of years for
diagnostics and OBDII? Doesn't that light the check engine light and
put in a trouble code?

I suspect a fuel tank venting problem like a pinched hose or blocked up
charcoal canister. To check for this just remove the gas cap and go for a
ride. TG

"fusQuanto" > wrote in message
news:20050206193355.4cc8463d.fusQuanto@yahooNOSPAM .com...
>
> 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