I have a 1988 chevy silverado and I think it is getting vapor locked. Is there a venting gas cap that can help

Answer 1

No,there is no vented cap that help vapour lock.

Vapour lock is the result of fuel "boiling"

Ever shake a Soda bottle while the cap is screwed on tight?
Not too many bubbles/foam,right?

Ever unscrew the cap on a soda bottle that's been shaken?
Lots of bubbles/foam.

That's a simple demonstration of the effect pressure has on a liquid.

Pressurized= no vaporization
Vented= vaporization at will,,"Boiling"

Same reason that Radiators have a Pressure Cap,,,to prevent Boiling,,,aka Vaporization of the Water into steam.

Any '88 anything in the USA must be DOT/EPA compliant.
Which means SEALED fuel tank.

Fuel tank ventilation is achieved via the fuel evaporative control section of the vehicle's emissions system.

A Vented Cap will definitely Worsen Vapour Lock.

Technically,,,a vented cap is the same as putting an open pan of gasoline in the sun.

Compared to putting some gas in a tightly sealed jar.

Which do you imagine would Vapourize/Evaporate?

You probably DON'T have vapour lock,,,it's a rare occurence these days.
But it's Possible.
If So,,then a vented cap wont do anything to Help.
Only make it worse.

Good Luck with it.

Answer 2

check with your favorite GM dealer parts department to see if your '88 required a vented cap. if it is supposed to have a vented cap and you are using a non-vented cap, vapor locking can occur or you can also collapse your gas tank.

I did that on a '94 6.5 turbo diesel Suburban that my wife left the gas cap at the gas station, I purchased a replacement at auto parts house that was non-vented (not knowing any better) and it completely collapsed the fuel tank on a fairly long trip to a soccer tournament.

certain years were designed to have vented caps and other years were designed to have non-vented and there was a check valve breather either build into the tank or in the fuel line to prevent vapor locking. check with your local dealer on which your should have.

other problems could be clogged breather, low pressure fuel pump, clogged fuel line or filter... or even stranger (had this happen too) a section of your fuel line might be rubber hose (transitioning between metal lines) and the hose needs replacing.

good luck

Answer 3

Check the following..

1) Fuel pump pressure (check the fuel filter too)

2) Location of fuel line (too close to engine heat?)

3) Dirty injectors on a fuel injected engine

4) Water, cr*p, or a foreign object(s) in the gas tank that periodically cover the intake. (p*ssed anyone off lately?)

The venting cap should not be the problem, but you can achieve the same effect to check this out by simply not tightening the cap.

.

Answer 4

Fuel injected engines do not vapor-lock due to the fuel being circulated back to the fuel tank.. Your problem is probably due to low fuel pressure. Replace the fuel filter first and if that doesn't help, have the fuel pressure checked and go from there.