Help read my fuel pressure tests for narrowing down my problem.

Vladimir2112

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1998 TC. 75,000 MI. In three years it put on 3,000 MI. The following three years it put on 70 MI. So that's the car's history. Turning the ignition without starting the car to prime the system. The gauge spiked all the way to 50 like a rocket making the fuel test gauge and Hose physically jump. And then crashed down to five immediately. I tried this a few times to see if I could get a pressure buildup but with the same result. Now I tested the pressure while the car is running and get a steady 30. Raising RPMs it still stays at 30. When I take the vacuum hose off the pressure regulator it goes up to 40. The regulator has good vacuum. And it goes back down to 30 when the hose is reinstalled.
This all started out as being a long crank before the car started. I replaced the fuel filter. Now it doesn't crank as long but the filter I took out looked practically new. Now the car starts. And I don't notice anything other than it didn't sluggish on the highway during acceleration around 50 to 60 mph. I don't know if this car is being sluggish now and I'm just not noticing it. My previous car was a crown Vic of the same year and I just figured it had more horsepower. And I read that the Lincolns were kind of sluggish to begin with especially with the four-speed transmission.
 

CuttingToolGuy

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Houston
Until someone more experienced comes along...

I suspect you have a leaking injector or a bad regulater.

To decide between the two, it is common to squeeze the return line with a pair of vicegrips to block it off and see if that changes the 'drop down' at your key on test. If the 'drop down' is much slower then the FPR is suspect, if the same look at injectors.

Be careful to not over do it and crush the rubber.

It could also be a check valve in the fuel pump but, I'm not sure if Town Cars have these.
 
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Vladimir2112

New member
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Until someone more experienced comes along...

I suspect you have a leaking injector or a bad regulater.

To decide between the two, it is common to squeeze the return line with a pair of vicegrips to block it off and see if that changes the 'drop down' at your key on rest. If the 'drop down' is much slower then the FPR is suspect, if the same look at injectors.

Be careful to not over do it and crush the rubber.

It could also be a check valve in the fuel pump but, I'm not sure if Town Cars have these.
Well the fuel pressure regulator did test a rise of 10 when I disconnected the vacuum hose. And drop back down to 30 when reconnected . no smell of gasoline or visible presence of it. I read that 30 is the proper fuel pressure. And when the car is running it holds 30 constant . I rev the car up and everything is holding it at 30. Turn the car off and it drops like a rock. Not slow. An
Immediate drop.
 

CuttingToolGuy

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Houston
Although the Ford spec is usually seen as 30 to 50 psi and you are in spec., you are barely in specification and right on the edge. Some people are fine that low and some have problems. Typically a 35 to 45 range is more 'normal'.

Clamping off the return hose will diagnose the pressure regulator. It may only be partially torn and still half way working.

I saw a thread from 2015 where @Town indicated there is a check valve in the fuel sending unit for a 1998 model.

I would eliminate possible problems in the following order:

Fuel filter
FPR
Injectors
Fuel pump circuts
Fuel Sending Unit
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Vladimir2112

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Yes I found out there is a check valve at the pump unit. And 30 is at the low end pressure wise. I'm pretty confident on that fpr being okay. What do you think ? I think I'm looking at dropping the tank LMAO. The only thing I haven't checked is my relay.
 
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