Vapor Lock Poll

RenegadeV8 · July 2nd, 2009

THis is a 2wo question poll.
Are u experienceing vapor lock symptoms THIS year ???
Did u experience vapor lock symptoms during 2007 ??? (2wo years ago)

Of course this assumes that u have been driving your vintage car for at least the last 3hree years.

Also, if u answered this similar poll at PackardInfo.com then your experience has ALREADY been counted.

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RenegadeV8 · July 2nd, 2009

no.
no.

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Dave@Moon · July 2nd, 2009

1. I came very close once this year, with an overpowering gas odor at start-up with one tank of gas, but no stalling or failure to start. (This in a Triumph TR6 that never gave me any trouble and has an aftermarket carb heat shield installed just in case.)

2. (As above), no.

Reatta Man · July 2nd, 2009

Dave,

I had vapor lock with my 2000 Lincoln the other day when the temp here in San Antonio hit 106. Never had that happen on a fuel-injected car before, but a mechanic told me it can even happen to them if it is hot enough. Opened the hood, let it cool off (ha!) and it started in a few minutes. Filled the car with Shell premium (no ethanol stickers on their pumps) and the car has run fine on all of our 100+ degree days since then.

Joe

ted sweet · July 2nd, 2009

no and no, but i only use gas with no ethanol.

joe_padavano · July 2nd, 2009

Quote:

Originally Posted by Reatta Man

Dave,

I had vapor lock with my 2000 Lincoln the other day when the temp here in San Antonio hit 106. Never had that happen on a fuel-injected car before, but a mechanic told me it can even happen to them if it is hot enough. Opened the hood, let it cool off (ha!) and it started in a few minutes. Filled the car with Shell premium (no ethanol stickers on their pumps) and the car has run fine on all of our 100+ degree days since then.

Joe

Sorry, but until your mechanic or someone else can explain to me how "vapor lock" can overcome the 45 psi pressure from your fuel injection pump (which is mounted inside the gas tank, not under the hood), I think the mechanic was full of it. The pump is immersed in fuel, (unless the tank was empty) so there's no "vapor" on the inlet side. The outlet side of the pump is under 45 psi unless the pump is going bad. Either you car has pressure at the under hood test port or it doesn't. If it does, there's no "vapor lock" and if it doesn't then you have a bad pump.

Skyking · July 2nd, 2009

No
No
No,
that's with two Metropolitans and a Buick, of course we haven't hit high temps yet, and the way it's been going, we won't.

simplyconnected · July 2nd, 2009

Quote:

Originally Posted by joe_padavano

Sorry, but until your mechanic or someone else can explain to me how "vapor lock" can overcome the 45 psi pressure from your fuel injection pump (which is mounted inside the gas tank, not under the hood), I think the mechanic was full of it...

Joe nailed it. Vapor lock is gasoline that BOILS. Either the barometric pressure must be real low (like in the Rocky Mountains), or extreme heat, or both. EFI engines have positive pressure which raises the boiling point, much the same as a pressure cooker. Most EFI's recirculate, passing any gasses back to the fuel tank.
Old-mechanical fuel pump setups were much more prone to vapor lock because they sucked gasoline fifteen feet, from the tank to the engine. In reality, many cases of so-called 'vapor lock' is nothing more than a loose fuel line connection, a clogged fuel filter, or rust - clogging the gas tank screen.

Reatta Man · July 3rd, 2009

First. the comment about my mechanic being "full of it" is out of line. He has had a major shop here in SA for more than 20 years, a radio show, is a certified mechanic, is a certified expert witness in state AND federal court on automotive issues and has documented several cases here in South Texas with vapor lock in our record-setting heat this year. You can claim it can't happen, but here in the heat, it is happening. Is the gas 'boiling?' Maybe not, but vapor pressure is possible and present without gas 'boiling.'

Second, you forgot to consider the effects of ethanol. While the boiling point of gas can be as high as 400 degrees, the boiling point of ethanol is 172 degrees. I can assure you, the temp most days around here under the hood of that Lincoln with that V8 under the hood is well over 172 degrees. I've not had any trouble since then while using gas without ethanol, even though it has reached 104-108 in many areas. Some people believe the ethanol content may be way above the 10% that everyone claims they are using.

This rush to call names, jump to conclusions and race to show how much smarter you are than the other guy is getting out of hand, and really spoiling what has until recently been a very enjoyable hobby. It's one thing when several people in here wish to call me names in the forum and in private messages, but to do so to someone you have never met just about reaches the height of arrogance.

One other thing--other car forums agree that it CAN happen, and manage to talk about it without calling anyone names.
Car Talk - Vapor lock problem?

Acura Repair: Vapor Lock code appearing, fuel delivery system, internal combustion engines

Car Talk - "vapor lock" -like symptoms

keiser31 · July 4th, 2009

Don't really know if it's vapor lock, but my truck will run o.k. for a while and if I stop somewhere, it will be hard to start .