vapor lock? hesitating '94 eclipse

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?

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.

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

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

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

Perhaps your computer is faulty!

BBA

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

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

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

At first you said the 2 (thats 2) mitsu dealers you had it to reproduced the problem & based my first post upon that. They should have, at that point, been able to tell what was lacking. The fact that someone replaced all your ignition parts, then went after your fuel system was a hint to me that both places were inept at proper diagnosis. All that stuff being replaced & you still don't know if it's spark or fuel tells me you spent alot of unnecessary $$$. Don't rule out something easy, like the fuel filter, but as posted above me here, know where to look. When it stops, check for spark, if it won't start & you have fire to the plugs, it's a fuel problem. Sit in your car with the doors closed (while it's working properly) with the engine off & turn the key to "on" (not start) & see if you can hear the fuel pump, if so, do it a coula times till your sure what it sounds like. The next time it takes a crap, turn off the switch, then turn it back on & see if you hear the pump. If not, your getting closer to your cure. Keep in mind that if you decide the pump isn't working at the time of your shutdown, it doesn't necessarily mean it's a bad pump. The computor & possibly a relay are involved with it's operation so tread lightly here too. Good luck.

ok thank you very much and to everyoen else too

i dont mean to reply to myself, but in reading the haynes it says the engine may stall due to a damp/wet distributor. my problem is only present in the mornings when it has rained overnight or is muggy/foggy in the mornigns. it says to check for spark first, so thats what ill do next time i have hte problem. and then it says if theres no spark to check distributor, and it says if it is damp/wet to wipe it with a cloth adn try again. it doesnt say why it is getting damp/wet. my distributor cap and rotor are new, but the distributor is 11 years old.

also ~7 weeks ago i changed hte pcv valve and the problem didnt come back until a couple of days ago. during that time it _has_ been damp, rainy, muggy, etc. and the car has worked fine. im not sure what to conclude from this. could it be the pcv valve temporarily fixed soemthing?

any comments?

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....

hrmm... well my car never heats up like yours did, it just stalls and shuts off. but thanks ill look into that too

Don't mean that the car got above normal operating temperature.

Just mean that once the car did get to normal operating temperature, the heat was eventually enough to drive the moisture out of the engine compartment.

Then, once it was warm and dry under the hood, the weak coil worked fine. Apparently a moist environment bleeds a bit of the "kick" off the coil, robbing it from the ignition system. With a good coil, its no problem, but if the coil is on it's last legs, it can be a problem.

this happened almost like clockwork right around 180K on both my Toyotas.

Car did not overheat, once car got to normal operating temperature, it eventually drove the moisture out from underhood.

i read in hte haynes that it could be a "damp distributor". next time hte = car acts up i will check for spark,adn if no spark i will check for moisture in the distributor. the problem only occurs early mornings (dont know if i forgot to mention that or not in my original post) so i think that may be i= t.=20 but when it rains during hte day, the car is fine... so we'll see. if it i= s a damp distributor, how do you fix that problem? is it a gasket or something?

On Mon, 07 Feb 2005 04:40:10 GMT "=AB Paul =BB" w= rote:

You could have a distributor with a hairline crack in it that is only visible with hi intensity light and careful inspection with magnifying glass.

For a quick emergency fix, just wipe out inside of distributor with dry Kleenex. For permanent fix, replace the cap. Also, no gasket, but it isn't against the law to use RTV silicon sealant where the cap meets the metal.

Lg