car wont stay running

[flashflores]

for about a 2 month period my car wouldn't start sometimes...it WOULD start, but only stay running for like 10 seconds, then drop. So i decided to change the air filter along with the fuel filter, cause they needed it. I tried to turn it over after i had replaced both of those and now i cant get it started again...my battery is good, fuel pump is good, im getting fuel pressure, new air filter, AND fuel filter...can anyone give me any ideas on what could be wrong...or at least point me in the direction i need to head, cause im at a loss.

[crcendo]

Hello, you may want to check out your Cam position Sensor.
I recently replaced this on my 2000 LS2 with 73k miles.
The vehicle would start normally at times, then shut off.. and then would not start at all. Changed that part and all is well.

[sierrap615]

please list model/year/engine/mileage

[flashflores]

2002 L200, 2.2L 58k miles, ....my friend is somewhat of a mechanic and knows quite a bit about fuel injection and has a voltage meter...all my fuses and that stuff is good...sides my AC GRRR...but neway, my dad being an old school mechanic doesn't know shit bout fuel injection but they both looked at it and tested the fuel pump, and pressure, and im getting pressure only enough for a start, then its dry...after a while it will build back up just enough so i can start it for 3 seconds then it will die....BUT my dad can bypass this problem by pouring gasoline into the throttle body while its running so.....any ideas?

[sierrap615]

Originally Posted by flashflores

and im getting pressure only enough for a start, then its dry...after a while it will build back up just enough so i can start it for 3 seconds then it will die

FYI the fuel pump only runs at two times:
1.when the key is turned to run, then it turns off after 2 seconds. this is to prime the fuel system.
2.when the engine is running, usilly controlled by the PCM from watching the crankshaft position sensor(RPM) or oil pressure sender. there are countless reasons why we don't want the fuel pump running when the engine is off, in addition some engines will automaticilly cut power to the fuel pump if there is no oil pressure(to prevent engine damage)

Originally Posted by flashflores

BUT my dad can bypass this problem by pouring gasoline into the throttle body while its running so.....any ideas?

are you saying the engine will start if you pour fuel in the throttle body? if so then does it die as soon as you stop adding fuel?

i don't know if the 2.2's fuel pump will cut out if the oil pressure drops or not. watch the dummy light next time you try. also try a NOID light to make sure the injectiors are getting the signal to fire. i would ask you to check for spark too but thats not that easy with the IDI system(no spark plug wires)

[flashflores]

yes...when i stop pouring gasoline into the throttle, it will stop..so..you think its getting just enough pressure for it to start, then it cuts, or what?....and it wouldn't start at all if the sparks were bad no?....oh and im gonna see if i can get a FP guage to read my fuel pressure...BUT i dont know how much pressure my model is supposted to read..?

[sierrap615]

i think the pump is running for the two seconds to prime the system but it may not be running when the engine cranks, because for some reason the PCM doesn't think that the pump should be running(like i said it typicly watches the CPS or the OPS). a multimeter or test light on the fuel pump should confirm this. but watching the oil light is a little easier

spark is a long shot. in a word, yes you need spark(i'm not saying its impossible to start without spark, just very very hard) and just because you have spark doesn't mean is a strong spark, or that you are not losing spark after cranking ends.

also, don't go to WOT during cranking, on most EFI cars cranking at WOT commands the PCM to enter "clear flood mode" where it injects almost no fuel. start cranking at closed throttle, and if you must, then go to partial throttle.