91 DOHC Starts then Dies/Stops Immediately

*** PLEASE HELP ***

CAR: 1991 DOHC, 187,000 miles, automatic

PROBLEM: Car starts, then dies immediately. Will not run after
starting. The start-up sounds normal, but then it just stops running.

HISTORY: For the last two months, Car ran great at 70 mph on the
highway. A few times while driving or backing at 5mph, car would die,
but could then be restarted immediately. A couple of days ago, while
slowing down for a turn, car stopped running. Car then began the
problem: start and die immediately. It did it when the engine was
HOT, and now does it when the engine is cold.

CHECKED SO FAR: Plugs & wires all OK. Fuel pump "whirrs" for 2-3
seconds when key moved to the "on" position. Oil Pressure builds
immediately to proper pressure on the short "start-up." Coilpaks and
wiring looks OK.

REPLACED SO FAR: Coolant Temp Sensor, Crankshaft Position Sensor.

WHAT NEXT?: Please advise as to what else might be causing this
problem. Anyone's advice on this is welcome.

 

How old is the fuel filter?

Ken

 

At the most basic level, three things are required for a gasoline
engine: fuel, spark, and air.

FWIW, fuel sounds like a highly likely suspect here. I would check
(change) the filter first, and then perhaps move to the fuel pump. Even
if you hear it whir, it may not be providing the proper pressure, or
failing intermitently possibly due to age or as debris is (are?) pulled
toward and blocking the pickup lines in the tank.

Check and change your air filter. A blocked air intake will cause all
sorts of fun problems as the PCM tries to figure out how to mix fuel
with not enough air.

-rj
98SL2

 

Exactly. Even with the higher technology, often problems come down to
a basic issue. A car my wife had would let us know when the fuel
filter needed changing. The car wouldn't go over 35 mph, then it just
wouldn't go.

Ken

 

****** Took your advice and changed the fuel filter but the problem
still continues. Also, there are NO fault/diagnostic codes appearing
to help further.

Does anyone have another idea to try? Could it be the KEY
ignition/lock switch? How would you test for that? I'm beginning to
grasp at anything!

THX everyone. *****

 

Here is a senerio...

When you turn the key on, the fuel pump will run about 5 seconds to prime the
system. Once the engine is running, the PCM senses oil pressure then allows the
fuel pump to run again.

Maybe the system is primed when you turn the key on, which will allow the car
to start, but not keep running because of an oil pressure or sensor problem.

James

 

Earlier post:

The switch in the oil pressure sensor would have to be bad which isnt
unlikely.

Another senerio would be the fuel pumps shot and not making enough
pressure. Buy a fuel pressure gage. Shouldnt cost more than 30 bucks and
it is a good tool to have around. You should see about 40-44 psi when
the key is cycled on and after the car is running or ran.

 

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7/17/04 1530hrs - PAUL REPLIES: Bought the fuel pressure tester.
Pressure is at 42 psi when pump whirrs. Little to no leak down/decay.
With engine cranking, psi is 36. So, this does not appear to be the
problem. Still no codes. WHat are the odds it is the knock-sensor ??
Btw, checked the wirinig for the oil pressure sensor, and it FEEDS
nothing except the gauges. The oil pressure on saturns appear to be
only for "show" warnings! They feed no computer!

Thx for your help.

 

So the priming shots not even getting anything to fire? Not even
starting fluid? I forget, did you say you checked for spark or not? If
you are not getting spark that should be the next big clue.

 

====================================================================

PAUL REPLIES 7/18/04 1000_EDT: The car starts and runs for 1-2
seconds, I am now getting Tranny Code26. Could this be the reason why
the engines dies 1-2 seconds after start ?

 

====================================================================

PAUL REPLIES 7/18/04 1000_EDT: The car starts and runs for 1-2
seconds, I am now getting Tranny Code26. Could this be the reason why
the engines dies 1-2 seconds after start ?

 

Yes! Refer to the current running post "**HELP** CODE 26 Transmission
Code - Car Starts then Dies" which it looks like you did.