sometimes when i starrt my car, it will either immediatly stall, or it will stumble really bad and if i gun it, it feels like there is a block in the fuel getting to the motor (its like it wants to fall on its face). 90% of the time it runs fine, however it failed emissinos a few weeks back and the air/fuel ratio was all over the place like it wasnt getting any fuel, and the NOx was 2.7 and needed to be <2.5 and the HC was something like 1.8x and needed to be <0.8x

im leaning more twords a fuel problem than electrical as the car has 116k miles but the plugs are ngk iridiums and have 16k, the wires are msd 8.5mms and have 16k, and the cap and rotor is an msd and has 10k, the rest of the opti is original...

this happens mainly after the car has been sitting for 3-4 hrs after i park it....or sometimes if its been sitting for a few days...

but then today once i had stopped for lunch for ~ 30 mins and it did it again, started up and immediatly stalled, and on the 3rd crank after stalling twice i gunned it just as it fired and heard it pinging a bit like it was starving for fuel......

its sitting at the shop right now cause i needed an oil change and decided to just buy a fuel filter and have them install it ($7bx for the filter and like $40 for the install) because i figure theres a good chance that's it, and i dont want to pay their $127 diagnostic charge to find out tis a $7 filter....

another reason im pointing at the filter is that the car sat for 4 months back in the spring and took a really long time to start up after i got it out, and has had this problem intermittantly since then..... and ive ran 2 or 3 differerent injector cleaners through it, so i doubt its a clogged/stuck injector?

after the car stalls once or twice or does the bucking idle thing, i can shut it down and it restarts and runs fine... (other than a possible a/f problem as shown on the emissions test)

any ideas what else it could be if not the fuel filter?

i hear the fuel pump every time i turn the key so i dont think its the pump but who knows

 

I guess you will find out after the filter is installed, but proof of a fuel delivery problem can be made with a test gauge attached to the fuel rail.

 

well since they quoted me $127 to diagnose my emissions/stalling problem, and a lot of people pointed to the fuel filter since it was stored for 4 months and since its totally intermittant... i guess its a gamble... its gotta either be the fuel filter or the injectors are leaking... i dont think a bad fuel pump would cause it since its fine most of the time so if i spent $50 bux to do the fuel filter/install and an oil change and that doesnt do it, ill do the $89 fuel system cleaner and still be in better shape than paying them $127 to just tell me its one of those 2 things, and then have to pay for them anyway (ie they said their $127 diag fee would not go twords any repairs )