safulop

Supposing your damper has bad vacuum, can this affect the vacuum force available for the heater valve? In other words, is heat leaking into the HVAC possibly due to these fuel line vacuum issues?

-Sean

SeanR

Only if there are other things wrong. They are supposed to be separate vacuum set ups.

I've seen quite a few failed FPR/Dampeners, not all that unusual. I test them each time I do fuel hoses or top end refreshes.

Speedtoys

Sorry...I was excluding the known errors that we have.

safulop

At risk of wandering off topic, but my car quite often has really "hot" hot starts. Meaning, it sometimes catches before the first crank is even completed, which sort of throws the start sequence out of whack and the fuel pump hasn't even started working yet; usually I just have to start it a second time. Is this a symptom of some fueling issues? It's like there is flooding in the line that doesn't belong in there. This is a fairly recent development, but the car runs better than ever generally.

-Sean

jcorenman

Like an injector that has decided to get leaky?? Do you have a fuel pressure gauge for testing? Stick it on the rail and see how long it takes for the fuel pressure to drop, when the engine is shut off.

Cheers,

finally!

Hmmm... how long after turning engine off should fuel pressure hold?

John Speake

It should hold at least 1/2 running pressure after 20minutes

finally!

WOOT! BIG SHOUT OUT TO SEAN! Went to his recommended guy, tested via tail pipe but without putting on rollers and passed with FLYING COLORS! AND Sean then tested my FPR and dampener and all in excellent condition!

Just one more year to do emissions test then no more!

THANKS SEAN!!! Owe you a beer or twelve at 3rd coast!

safulop

So then if I had a leaky injector, wouldn't I have trouble starting the car after a while, because of low pressure?

Congrats to OP concerning smog, I know it is a nail biter for me here in CA. I passed by 1 ppm in both of my recent test in the past 2 years.

-Sean

John Speake

Depends on the rate of leak. Too much could flood one cylinder until it is cleared with the other running cylinders. Any loss of pressure is only a problem when the under hood temps are high, allowing vapourisation of the fuel. The resulting vapour lock can make the car very hard to start as the fuel pump can't move it. So you then have to wait for everything to cool down.

Leon Speed

So the difference was rooling vs stationary?

JHowell37

What did he do besides test the car again?

finally!

Nada... He simply tested at the tailpipe like before BUT without putting on the rollers...

Speedtoys

There is no test method requirement?

finally!

From what he told me it is the operators decision with a major factor on using the rollers or not being safety. He said he is not comfortable due to inadequate tie down points in putting some cars, the 928 being one, on the rollers. He just puts the probe in the tailpipe, and runs the tests that way. He said as well the lack of load on the wheels makes much easier to pass...