93 Chrysler 3.8 Fuel Bar Pressure

Our 93 Chrysler New Yorker 5th Ave. has 150K miles. Runs great except
starting first thing in the morning. Must give it the 1,2,3 then crank
and it starts. Good for the rest of the day. What is the cause for the
loss in fuel pressure in the fuel bar?? How can this problem be
solved?? Bob

 

Faulty fuel pump outlet check valve and/or faulty fuel pressure regulator
and/or leaking injector(s).

Diagnosis and repair.

 

I've got a 93 3.3 and am having the same problem, I think. With mine, I
have to turn the key completely off and then back on 1 or 2 times and then
it starts. Is that what you have to do also ?

I've replaced both my fuel pump (went out on vacation) and fuel rail, which
included the pressure regulator (the rail sprung a leak).

Is there any way to check the injectors other than pulling the rail and
looking at each one ?

thanks,
Nick

 

Not so much "looking" as wrapping the squirter end of each injector in a
tight twist of paper towel and coming back the next AM to see if any of
the wads of paper towel smell of gasoline.

 

ok, thanks for the tip. Didn't want to take the plenum off and pull the
rail, but if that's what it takes, I gotta do it.

I was also thinking of putting a pressure gauge on the test port of the
rail, note the pressure, leave it on overnight and then check it in the
morning.

thanks again,
Nick

 

install a fuel pressure gauge. start vehicle and let idle for two minutes
then shut the engine off
monitor fuel pressure. if the fuel pressure drop more than 15 psi with
20-30 mins the check valve
inside the fuel pump is no good and therefore pump must be replace. if
pressure is dropping very slowly and it takes the next morinng to loose 10
psi your injectors may be leaking. but most of the time its your fuel pump

 

Nick, We have the same problem. I have to shut off the key 3 times for
it to start. Placed pressure gage on Fuel Bar and did not loose
pressure in 15 minutes. Next step is to leave gage on over night to see
how much it drops. Running pressure is up to 50 psi. Engine runs too
smooth to be a fuel pump problem. Bob

 

Thanks Bob and tdodge, based on everyone's tips and help, it looks like the
injectors might be the problem. Coming home from Florida in August, our
fuel pump went out. I had it replaced at a Dodge dealership in Lake Norman.
So I think I can rule out the pump. The rail was replaced earlier in the
spring because it sprung a leak. I replaced the ASD and fuel pump relays
and the coolant temperature sensor.

So I'll check the fuel pressure next.

thanks again,
Nick

 

Bob, please post back if you find the problem and I'll do the same.

Thanks,
Nick

 

Nick, The pressure has dropped 5 psi in about 30 minutes. The auto is
now being checked to see if it leaks down over night. I wonder if a
good fuel injector cleaner might help? If so what brand should I buy?
Will get back to all you in the morning and give you the results of
overnight pressure loss. Bob

 

Pick up a set of matched-flow replacement injectors from the "injector
guru", www.lindertech.com .

Aside from actual fuel supply line leaks, the injectors are pretty much
the only leakdown point left!

 

That works to tell you you're losing pressure (duh, you already know
that!), what you need to do is figure out *where*.

 

thanks for the advice. I don't have any fuel line leaks. Also, this
problem began before the rail started leaking and before the fuel pump went
out. When I replaced the rail, I thought, 'oh this must be the problem',
when I had the pump replaced, again I thought, 'oh this must be the
problem'. Well neither fixed the problem, so your comment about the
injectors being the only component left, sounds about right.

thanks,
Nick

 

I've had best results with (Dupont?) Techron Fuel Injector Cleaner.
Unfortunately, it is also the most expensive.

 

Nick, As promised!! After the overnight checking of the psi on the
Fuel Bar it was down to "0". I gave it the 3 second 3 interval and then
cranked to a start. Pressure then came up to 50 psi. I watched it for
45 minutes and then it started to drop. It dropped fast and shortly was
at 10 psi. At this low pressure it still started with ease. I
purchased the best injector cleaner and we will see if that will have
any effect. I am still puzzled as to what might be the problem.
Bob

 

Bob, based on other posts to this thread, it appears one (or more) injector
is leaking and relieving the pressure when the engine is off. They
suggested replacing the injector. Someone suggested pulling the rail and
wrapping a napkin or paper towel around the injectors overnight to see which
ones are damp with gasoline in the morning. I haven't got that far yet, but
plan on it. I also need to check out the price of a complete set of
injectors. Hate to replace one and have another go out in a few months.

Nick

 

Nick, I have never changed the fuel pump on ours, so I am inclined to
think it is the pump in the gas tank. Ron made a good point earlier.

Yours may be the injectors. Daniel suggested wrapping the injectors
with towels. He also made the comment:

The key words here are "Matched Flow". If I must replace the injectors
I will replace them all at the same time.

Nick, we could correspond directly by e-mail, but I feel the other guys
have been a help and maybe we can help others. Bob

 

If it were in the shop and had an emissions analyzer they would be able o
detect which one is bad by sniffing the runners of the intake

If it were in the shop that had an emissions analyzer they would be able to
detect which one is bad by sniffing the runners of the intake, The excessive
hydrocarbons would fail it
Glenn Beasley
Chrysler Tech



=----

 

Bob;

I'll tell you when my fuel pump went there was no warning. It just quit on
I77 heading north just outside of Charlotte. Now maybe something in your
pump is bad that allows you to drive it without a problem, but is causing
your hard cold start problem. Someone mentioned a bad check valve. I think
you were going to try the injector cleaner to see if that might work. Let
us know. I'm checking prices on injectors.

thanks,
Nick

 

Nick, The car runs great!! The problem is only in the first start of
the day. We go through the 123 then crank and it is fine for the rest
of the day. It may sit for several hours, but start right off after
that initial start. Bob