2000 q45 wont stay running

[andyxle]

having a problem with my 2000 q45. 141k on odometer.drove it for the last year and a half with no problems whatsoever. when i tried to start it this morning starts and runs for about 3-5 seconds then dies. even if i give it gas the motor will rev up but will still die out within 3 seconds. no CELs. replaced all coilpacks about 8 months ago. i noticed when the car is running for the short amount of time, the security light stays on the whole time. also when i lock the doors with the keyless entry, the security light no longer blinks. can this problem be related to the immobilizer? or could it possibly be a fuel related issue.tried another battery in the vehicle and it made no difference. i disconnected the battery over night as well and still have the problem. i changed the fuel filter about 10k miles ago, im going to do it again just so i can rule it out. has anyone ran into this problem before?

[elwesso]

Sounds like a bad or weak fuel pump. A fuel pressure test will confirm. When you turn the key on (but don't crank it), you should see about 44 psi. At idle, you should see 34 psi.

the fuel pump could be working enough to provide enough pressure for it to start, but no more.

[andyxle]

the car was putting out 30 psi with key on and 43 while cranking. should i go ahead and replace the fuel pump? the security light stays lit solid when i arm the alarm with the keyfob. is this a indicator there is an issue with the immobilizer? looking in the FSM it only states that its a problem with the immobilizer when the secuirty light stays solid while cranking

[paranoidjack]

Is it the exact same amount of time it stays running every time, the 3-5 seconds?

Or does it vary?

Will it rev up to 5 or 6,000?

I'm thinking immobilizer issue is right. Factory alarm?