Vapor Lock, How long? Options

[Ctrout]

I'm having this trouble with my car. It is acting like vapor lock but it takes a long time for it to start again (like 4-6 hours). How long does it generally take for a vapor locked car to start again on a 95 degree day?

[smg914]

Four to six hours is way too long. Sounds like your problem is a little more serious than the typical vapor lock issue.

[ArtechnikA]

It is acting like vapor lock but it takes a long time for it to start again (like 4-6 hours).

you say this because the engine will crank and crank and yet not start ?

what year is your car? has the fuel pump been relocated to the front ?
is it still injected or is it carbonated ?

the standard way of curing vapor lock in a DJet car is to cycle the ignition switch - off-to-on, off-to-on - enough times for the 2-3 second initial fuel pump run to pump fuel vapor out of the fuel loop and replace it with cooler fuel from the tank.

the new fuels are a lot more volatile than these cars were designed for; "they" keep trying in their various ways to get old cars off the road ...

[Ctrout]

It's a stock 1.8 wiyh L-Jet. Fuel pump is in original location. Symptom, the car runs fine. I can let it run until it reaches operating temp then shut it off. When I do this, it won't start again for hours. I haven't run it under load yet as I am still trying to get it registered. I ran it near empty and thought the problem might be gas tank crud but I pulled the tank last night and the screen didn't look clogged enough to block fuel flow. Slow it a bit maybe but not stop it altogether. I'll be replacing the fuel filter today to see if that helps.

[SirAndy]

When I do this, it won't start again for hours.

i think rich wanted to know if the starter still cranks?

when you say it doesn't start anymore, do you mean the starter cranks but it won't start up or do you mean the starter won't turn until cold again?

Andy

[SteveL]

If the starter is no cranking, this sounds like typical hot-start issues. Replace the ground cables and clean the end connection points. I also install the hot-start relay, and haven't had the problem since on my 74 1.8.

Steve

[b81651]

I have a '76 2.0 which seems to be having the same problem. After driving for more than 1/2 hour, the car gets very hot and will not start unless I let it sit for a long period of time. I found a leak at one injector hose and replaced all of the hoses. The car still heats up and will not run after a long period of time. The person that I bought the car from did not know a whole lot about the car, so I don't know what was done and what was not done. Can you give me a suggestion on where to go next?? I've been told that I should get the fuel mixture (O2 ) checked on the car. (IMG:style_emoticons/default/confused24.gif)

[ArtechnikA]

Can you give me a suggestion on where to go next?

start with the basics and do ALL the tune up stuff.

change the oil & filter; get good new, quality spark plugs, gap them to specs, and put them in, checking your spark plug wires as you do.

if you don't know how long it's been since your fuel filter was changed, replace that. check for vacuum hoses - leaks are bad. check your trigger points. check the fuel pressure. adjust your ignition advance EXACTLY to spec. adjust the valves. clean every ground you can find.

only after you've addressed all the normal maintenance items should you be looking for specific issues.

and guys - 914's have TWO, SEPARATE hot-(no)start issues.

in one of them, you turn the key and nothing happens (maybe you get the initial buzz from the fuel pump if you have a DJet. i don't think LJets do that but don't hold me to it...) this is a starter issue

in the other, you turn the key, the starter cranks the engine but it does not start. this COULD be vapor lock but it can also be other things.

but you HAVE TO be more specific on EXACTLY what's wrong so people don't spend a lot of time trying to help you fix a problem you don't have ...

[SirAndy]

the car gets very hot and will not start unless I let it sit for a long period of time.

will not start as in "does not crank over" or will not start as in "cranks over but won't start" ?

Andy

[Ctrout]

It will crank but will not start. I pulled the fuel tank. Very clean. Changed the fuel filter. Already replaced all the fuel lines in the engine compartment. All injectors are squirting (while it's running) thanks to Slits (IMG:style_emoticons/default/wink.gif) . It seems to run very well too although I haven't driven it yet because the guy who has to inspect it before issuing a title won't return my calls. (IMG:style_emoticons/default/ar15.gif)

[Cap'n Krusty]

[QUOTE]the new fuels are a lot more volatile than these cars were designed for; "they" keep trying in their various ways to get old cars off the road ...

Not true, at least the part about more volatile. They're LESS volatile. Fuel will puddle oin the intake and not evaporate, leading to starting difficulties, though I doubt this is the case here. L-jet cars suffer from extreme sensitivity to vacuum leaks, and this can cause no starting under warm/hot conditions. After doing a proper tuneup, including valve adjustment (with new gaskets), compression test, points (& setting the dwell and timing the correct way!), and plugs , look at the condition of the 2 oil filler cap seals. Common problem, and still available. The Cap'n

[Mueller]

have you replaced the dual relay for the fuel pump/injectors?

[airsix]

You may infact be getting vapor lock then. High temps combined with your altitude (~3,200 ft ASL) could lead to vapor lock. The key to preventing vapor lock is keeping the fuel in the lines under pressure. Even a little pressure. Since you've been running with very little fuel in the tank that in and of it's self could be a contributing factor. If you fill the tank full, you put a greater "head" on the fuel in the lines. In other words, the fuel in the tank above the lines will bear down it's weight on the fuel in the lines and increase the pressure slightly. That additional pressure might be enough to eliminate the vapor lock issue. I suspect the vapor lock is occuring between where the fuel line exits the firewall and where it enters the pump. This area is close to the exhaust (hot) and just upstream from the pump inlet (low pressure). Those two conditions are the makings of vapor lock.

-Ben M.

[mikerose]

Head temp sensor. My old 1.8 L-JET did this all the time. Come on Mueller you know about this

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