Car die's twice while driving

[kkat]

I just bought a ( 1991 olds cutless supreme) with 98.000 orginal miles, ( yes this car was owned by a little old lady who just drove it on sundays) I test drove this car for 30 minutes at highway speeds and in city traffic and this car ran great, 3 hours later Im driving home in my new/old car and it starts to buck and spit and comes out of it and then a few miles down the road it bucks and spits again and shuts down, ( acting like it was running out of gas) and would not start, thinking it was perhaps out of gas I poured in 2 gallons and after some cranking it started ( time frame of about 1 hour from shutting down to getting gas) so the car sat a while. Maybe 2 miles down the road the bucking and spitting stared up again and the car shuts down again and will not start, act like it wants to but nogo. I can hear the fuel pump when Im turning the key so Im thinking that the pump is ok or can a fuel pump run intermittily? I put in a couple bottles of dry gas thinking maybe water in the system and being the perfect weekend to tinker Im looking for suggestions as to what route to take. Im going to replace the fuel filter etc and will take a fuel line off and see if the pump is working but again can a fuel pump work and not work? and I dont think its ignition or electrical IMHO but then again. both times it died it seemed like it was starving for gas and I was able to pull out of it at least for a couple of moments by pumping the gas as the problem was happening. This car is in really great shape ( so I thought ) except for this problem and is worth to me to fix it instead if trying to get my money back, thanks again guys for the help, always very helpfull

 

[Jim 5]

Start by changing the fuel filter, but it could be that your fuel pump is going out. This happened to me when I was on the highway 30 miles out of town. I limped it in to the nearest GM dealer and had the fuel pump replaced. Problem solved for the next 65k till I sold it.

Good reason to replace the fuel filter on a used car. The dealer said the filter was almost plugged (just bought this truck) and that had taken out the pump.

 

[tomcat27]

do you have a fuel pressure tester? next time it happends, connect a fuel pressure tester to the schraeder valve on the fuel rail. if you have around 40 psi, you have fuel. if not, try turning on the key on listening for the fuel pump to see if its running - you can normally hear then run for a few seconds until pressure builds. try it now to see what it hears like.

if you have fuel pressure, then I would look first at the ignition module (it might be combined with the coil pack) or a crankshaft position sensor. (you will only have one of those if you have multi-port fuel injection - throttle body FI doesn't have one.

 

[mstrjon32]

In my experience the GM ECM in this vintage of cars is sensitive to the upstream O2 sensor input. Try unplugging your O2 sensor and see if the car runs any better, if its running smoothly with the sensor unplugged (but likely eating up gas) then its probably time for a fresh sensor.

I've experienced the exact symptoms you are describing in two different cars, a 1997 and a 1989 and both times a new sensor cleared it up.

It's a quick and easy check before you start replacing fuel system components.

 

[mechtech2]

Any engine codes/dash lights?
This could be bad gas, or any other part or system, at this point.

 

[H2GURU]

You're not getting constant fuel supply, Check fuel tank straps, if they're original then plan on a new tank and supply lines, Rust is in tank, as you drive it passes-floats over your outlet causing starvation. This car sat for LONG periods and many slightly driven cars that only run for 7 minutes to the store or church will exhibit this problem when "pushed past the 10 minute" limit.

 

[kc8adu]

most common cause on these cars is the crank sensor.
they tend to run ok till warmed up then go intermittant.
have to pull the crank pulley to change it.
this is for the 3.3 and 3.8.