Matt Hohmann

hello =all - im a retired mechanic=Have an 1988 olds cutlass wth FWD & 2.8 engine . Help me with a problem or guide me where i can get help =please! The car will start =run fine & die - all quickly! i have great spark, good compression & 42 psi fuel pressure @ fuel rail. Cranks -no start! Ocassionslly it will start & immed within 1-3 seconds will shut off & no restart! Anyone know or have experiences with this?? Is there an oil pressure switch (sender) that shuts off fuel pump? I have recently replaced the fuel pump, fuel filter, ign module, checkes coils -all good - & giving hot spark. What can this be ?? Thanx to all!!

Nufo

Just prior to this event happening, did you happen to do anything with the battery? Jump/boost the car or do anything that would affect draw on the system? Some systems will deactivate circuits to protect themselves. If any of things occurred, disconnect the battery cables and touch them together for 10-15 seconds. It will drain the voltage that the ECM is still holding. If none of the above happened, then it would be mechanical possibly... Hope this helps...

Nufo

ah64pilot

Have you checked the throttle position sensor? I had this same experience on '96 Firebird...it would start but as soon as the computer went into open loop (or closed, I can't remember the terminology) it would shut off thinking the throttle was completely closed. It's a shot in the dark I know, but it's worth looking at.

72 cutlass455

Had a 88 grand am the cam shaft position sensor would get hot and quit dang thing took my coil packs with it. This sensor tell the computer where the number 1 cylinder is so it can follow the sequence.

nofiveo

There's 3 rules to fixing cars..

Always start at the beginning

Always check it yourself

NEVER trust the customer!

The first thing you need to do is figure out what it's missing when it won't run.. pull a plug wire and check for spark. If you have spark, then you'll need to start looking at fuel delivery. Just because you have fuel pressure dosen't mean the injectors are actually firing. Pull the intake boot off at the throttle body and spray some carb spray into the intake, does it try to run? If so, you'll need to pull the plenum and ohm the injectors. They should be around 12.4. Try these quick things and post back.

knighthawk

you didn't say how new it is ...if you replaced the ign key that had a 'chip' in it with a new one that don't, it will also do that

Matt Hohmann

Thanx to =ALL- i will get these things checked Today & post results here .

stellar

mass air flow sensor

Matt Hohmann

Ok heres where I am -replaced the mass AF sensor. Disconnected battery 9still no codes) and grounded pos & neg terminals to each as suggested. Checked for spark-all sparking & very hot i might add. Fuel is at injectore. Fuel pressure good . Pump runs -turns off as should prior to running . tried starting engine- started!! let run & within 30 sec - i tried to raise good idle rpm= engine died like i turned off the key. no =restart!! exhaust system is good -no restriction to flow. where do i go from here ??still no codes showing in code reader also I am at a loss -if any sensors are bad i would expect to have some code reading?/-if i return to it i will again disconnect battery & grounf both term again & i do expect it to run. Could i have a bad TPS?? whats next -thanx =

ah64pilot

I believe a guy above mentioned the TPS as the first place he would look That's where I would have started. I didn't have codes on mine when I had that problem because at idle it was working just fine. When you move the throttle the resistor is supposed to signal the computer to add fuel and timing but if it's bad it will either run horrible or not at all. I think they are relatively cheap...can't hurt

nofiveo

Ok, that eliminates some things...I'm leaning towards a crank sensor. Are you using a "code reader" or an actual scanner? If it's a scanner, check to see if the ECM is showing a RPM reference when cranking. If theres no signal, it's most likely the crank sensor. They are relatively inexpensive, but can be a headache to change. It's located on the back of the engine towards the bottom.. should be 1, 8mm bolt holding it in. Be very careful with the sensor! if it breaks off in the block you will hate your life!! I've had the best luck with repeatedly soaking it with penetrant while working it back and forth. The o-ring sticks so do not force it! Good luck and let us know what happens.

Matt Hohmann

yes - code reader only & that was a bad part - i did replace it & yes came out in pieces -but got it all out . I believe that was origional problem - i also replaced the o2 sensor. along with that .