97 Concorde no start

I've got an interesting problem with my '97 Chrysler Concorde (3.5L), in
case you've been following the news it's COLD up here in the northeast,
and ever since I've gotten this car it's been very hard to start in the
cold, and the colder it gets the more trouble I have starting it (like
it doesn't want to fire) until a day like this morning when it was near
zero, it just won't start at all. As it cranks it feels like it fires a
few times, but not enought to start it. I'm not sure if it's too
flooded to fire or it's not firing. Later (once it warms up outside) it
will eventually start, missing, stinking like an old lawnmower, and
running awful for 5-10 secs. until it levels out. Then it will be fine
and never repeat itself until the weather is cold enough. It starts and
runs great all summer. Two dealers and an independent garage can't find
the cause. They think it's a sensor, but which one they don't know,
maybe crank, maybe coolant temperature. The problem leaves no trace in
the computer's diagnostic logs. Something's certainly out of whack
because when I filled up this week I managed to pull a remarkable 12
miles per gallon in the last tank.

Has anyone had this kind of problem? If someone can lead me in the
right direction I'd be appreciative. It's not like this car is in bad
condition, I take good care of it and can practically eat off the
engine, and I intend to keep it for a while yet, but it's done this
since the day I bought it used a few years ago and every mechanic is
stumped. I'm tired of bumming rides with co-workers and friends to get
around.

Thanx...
Matt

 

Pull the codes and see if that gives a clue. Also, if I remember my
owners manual correctly, isn't starting with the accelerator pedal held
partway down recommended below a certain temperature? (whatever it is,
I've never had my wife's 93 in temperatures cold enough to bother). Even
if its not, give that a try and see if it fires up. Might save you some
misery while you track down the problem.

 

have someone check the fuel pump for a bled down issue and make sure the
regulator is working correctly too the pump should not go below 10 psi over
nite

 

In the owners manual it stated that you want to press the throttle fully for
a cold start condition when the temp is below 0f. You might try that when
it does it next.
Also, the 12mpg thing sucks. My 3.5 LHS never got below 21 even in frigid
temps. Something is running rich. Sorry, can't help more with that unless
you can get some more info.

Steve m..

 

Try starting fluid. If it starts then you have a temperature sensor gone
(possibly telling the ECU the temperature is something like 200F - this
would explain why it is worse in cold weather).

 

Thanks for the fast replies... here some more info for your posts.

I tried for codes, there are none in the computer. When the problem
goes away it leaves no sign it was ever there. Every sensor on the car
I can read is within spec, and the dealer and the independent shop concur.

Pressing the gas part way or completely makes no difference when it
decides not to start. When it's warmer outside and it's giving hard
starts it does help to hit the gas a little and gets it going. However
when it's just at the boundary between when it's hard to start and when
it won't start, it'll race when it starts even without my foot on the
gas at all, not badly but it will run up to 1500-1800 RPM for a few
seconds and slowly come back down.

The fuel system and pump appears to be working, because it's certainly
getting gas when it's not starting, too many tries to start it and it
floods out. Last time I had it in for a check for this problem they
claimed the fuel system was good. I know it runs horribly rich when its
cold outside and the engine's cold, the exhaust smells like it's too
heavy on fuel and it's a dog until it warms up (granted I go real easy
on it but there's a noticable loss in low end torque when it's cold).

Outside of that she's fine, the idle's a little rough (every couple of
seconds the engine kind of 'twitches') and there's a faint flutter
(slight dip in power for a second) under moderate acceleration below 3k
rpm, but always starts and never gives me any sign of trouble. I
figured I needed a tuneup to smooth that out. If my coolant temperature
sensor was really out of whack wouldn't I see it on the temp gauge or
does that gauge read from a different sensor? I've tried scanning it
when it's running right and the temp after a 20 minute highway drive in
cold weather then a few minutes of idling was in the mid 100 degree
range which sounds about right.

Thanks for the help, you've been much more useful then the local dealer.

-Matt