Magik

Ok..that is what I have been told or it has been suggested that is what is going on with my car(1990 Civic HB/4-speed Man/1.5L)...here's the gist of it:

I go to start my car and all it does is turn over...no problem turning over...will attmpt to turn the car over several times...usually by the 8-10 time it starts up. Also occurs more frequently on very warm days.
Now my Dad suggested the vapour lock and asked if I heard a hissing when I opened my gas cap...filled up two days ago and got a loud "Pssshhhhh" when opening cap. He told me that the next time the car won't start to get out open my gas cap and release the 'psshh' and see if the car would start. Today, car wouldn't start, attempted to turn over once and then went for the gas cap, it was very tight. Loosened and replaced, got back in car and "Vrooom"! It started and off I went.

Question 1: Does this sound like Vapour Lock ?
Question 2: What the hell IS Vapour Lock?
Question 3: How do I get rid of it? (Is this something I can fix myself or am I better off letting my mechanic do it?)

ANY help is greatly appreciated!!!!


Thanx in advance

Magik

WhiteRice

It sounded at first like you weren't getting any spark..because it would just turn over. If it's not vapor lock, check your distributor (rotor) and plugs/wires.

Sorry, I'm not familiar w/vapor lock though.

Magik

Taken from: "Gasoline Volatility" by Jim Kerr at the site:

http://www.canadiandriver.com/articles/jk/at_000814.htm

"Vapour lock refers to the situation when the fuel boils in the fuel lines so it cannot be delivered correctly to the engine. When vapour lock occurs, the engine operates as if it was running out of fuel."

That help?....can anyone help me?




Magik?

jaje

vapor lock only happens when your engine is already hot and you are trying to restart it...reason is the fuel in the injectors and injector lines gets hot and boils...however once its running it is not a problem b/c new fuel is pushed through the injectors cooling them

the psssst...you hear when undoing the gas tank is the result of heat that expands the liquid fuel and air in the gas tank...(only when it is warm out, the car has been running for long periods, or the car was driven hard)

vapor lock is unlike boiling ones brake fluid b/c the gasoline is burnt and constantly refreshed by cooler fluid...where the brake fluid has no avenue to cool properly (besides brake ducts)

when starting a cold engine there is no vapor lock and releasing pressure in the gas tank does nothing...it is probably distributor or main relay acting up...there is another post in this forum

1stGenCRXer

Could be a sign of a weak fuel pump. If the fuel tank is already pressurized before starting, the fuel pump may have difficulty cycling the fuel, where releasing that pressure would help equilize things.

Magik

What your saying is what that gentleman said in his article is in a way inaccurate? or to be so bold, wrong?
Was it pure coincidence that the car would not start but as soon as I released the pressure built up in the tank, start it did!
The main relay is fine, could be the fuel pump but it has good ground and is getting power...it could just be failing but I don't think so (hope not), I'm getting spark...sigh...
I have a solution...gotta match?

Magik

WhiteRice

would clogged injectors be causing gas not to get to the engine?? maybe try to clean your injectors.

jaje

the article makes sense but i don't see it as relevant to your situation (you cannot have vapor lock unless the engine is hot [very hot] b/c the pressure in the system [just undoing the gas cap will not relieve the pressure in the fuel pump where vapor lock would occur])...check out this explanation to help http://autorepair.about.com/library/.../bldef-856.htm
(physics if you want it: http://www.madsci.org/posts/archives...7548.Ch.r.html)


actually 1stgen brings up a good point about the fuel pump could be dying on you which would lead to why undoing the gas cap helps it get fuel pumping again

Magik

How do I 'know' if the fuel pump is dying...is there a way to test this? Also, by cleaning my injectors...how?
I appreciate greatly all of the input fellows...ANYthing you can suggest for me, especially that I can do myself and how, would be extremely helpful. This is my daily driver and my only way to work...so it has to run...

Thanx again...

Magik

1stGenCRXer

You need a fuel pressure guage to check the fuel pump, if the pressure drops during acceleration, it isn't keeping up; or, in your case if it isn't building sufficient pressure at all with the condition of the main tank.