Bad leakdown test?

[dburgjohn]

At the advice of a friend, I did a leak down test on my 92. Put the gage on, turned on the key for a few seconds then off and watched. Here are the pressures:

7:00 PM 40 psi
7:10 PM 26 psi
7:20 PM 18 psi :eek
7:30 PM 14 psi
7:40 PM 12 psi
7:50 PM 9 psi
8:00 PM 6 psi ad

I am pretty sure it should have held a higher pressure longer. Any fuel experts out there can offer me ideas of whats wrong and what to do. Car seems to run good. However if you run it, shut it off for a short while and re-start it starts hard. Leave it set for a good while and it starts fine.

Thanks

 

[8388]

Time to start pulling spark plugs. More than likely you have one or more leaky injector. spark plugs that are saturated with fuel will cause hard starts. If you find that some are leaking, I would recommend replacing all 8, cause more than likely the others will follow.

 

[dburgjohn]

Leakdown with clamps

Did a leak down test again, but this time clamped the feed and return lines at the tank after pressure built up. 45 min and no loss in pressure. What is involved in changing the valve in the gas tank?

 

[Moonunit 451]

Same thing happened to me ------ time for a new fuel pump. It's not that difficult a job, but pay strict attn: to the direction and location of the float when you remove the pump and put it back in the same location

 

[Tuna]

same thing happened to my 96 a few years back - 44psi to less than 10 in seconds, not minutes.

There is a check valve in the tank unit that is not holding pressure. Made my 96 hard to start sometimes since the pressure did not recover fast enough.

Time to replace the tank unit. While it's out, check out the tank and look for signs of rust.

 

[Robertwav1]

Took apart a sealed fuel pump recently"Borg Warner". There is a check valve in the pump itself that keeps pressure stable.