91 Chrysler New Yorker 5th Avenue

I have a 1991 Chrysler New Yorker with a 3.3 l engine, over 90K miles. It
is getting very hard to start. It cranks a long time before the engine
fires. I have replaced the fuel filter, checked fuel pressure(47lbs.)
Does anyone have any ideas? Any help would be greatly appreciated.
John

 

Is your hard starting every time you try to start the car, or just first
thing in the morning?

 

It is hard to start if it sets any length of time.

 

Probably because your fuel system is losing pressure as it sits, so the
pump must refill and repressurize the entire system before the engine will
start. This could mean the pump's output check valve has failed, or it
could mean your fuel pressure regulator is faulty, or it could mean you
have a small and undetected leak in the pressure supply side of your fuel
system.

DS

 

Easy way to test that (pump losing pressure). Turn the key on, wait about
5 seconds, then try to start it. If it starts right up, the pump is
losing pressure. If it doesn't, you may want to check your spark plugs.

 

The test you suggest will tell him nothing at all. The fuel pump runs for
only a second or so on initial key turn-on, not enough to refill and
repressurize a seriously drained system. It is a common myth that there is
a pressure sensor and the pump runs until a particular pressure is
reached. There is no such sensor.

A variant of your test that would come closer to revealing a fuel system
drainback condition would be to turn the key to "on", listen for the fuel
pump whirr to begin and to stop, turn the key "off", turn the key back
"on", listen for the fuel pump whirr to begin and stop, turn the key
"off", wait 45 seconds (induced prime will only occur twice within a
35-second period) , repeat, and *then* try to start the car. If it fires
right up, the fuel system is losing pressure.

If no fuel pump whirr on initial key-on, there's a problem with the fuel
pump relay or its circuit, or there is an engine control module internal
problem.

DS

 

I have the exact same problem in a '94 Ford Tempo (pressure falls off when
not running). I have to turn the key on, listen for the pump to stop
running, then it starts instant. Otherwise it sits and just cranks away.

I doubt that the entire fuel system from the injectors back to the tank
are draining dry, it's just losing it's pressure, and letting the pump run
before cranking the engine is an easy way to check that.

The other way is to hook a pressure gauge onto the fuel rail at the
injectors and leave it there while it sits overnight. See what pressure
the system has before attempting to start.

 

ok will try the test, if it is infact loosing pressure, is there a way to
fix it without replacing fuel pump? Is the check valve on the fuel pump
or somewhere on the outside of the tank? I really do appreciate all the
help!

Thanks
John

 

I'm sure there's a check valve made by someone, and a mechanic who will
splice it into your fuel line just downstream of the pump. Is it a good
idea? Who knows?

Built in.

DS