Just an order of events, I drove about 8 miles to a fast food place, placed my order and as I pulled away the car stalled when I let off the brake to move my foot to accelerator. It runs if I hold the throttle down. I don't hear any vacuum leaks and I'm unable to pull a code at the moment but just based on these symptoms, should I start with the IAC or MAF? I'm kinda tight on cash at the moment and I'm just going attempt to throw parts at it, well just those 2 but of those should I start with the IAC as being the most likely suspect?

  • When you hold the throttle down, are you holding it to the floor, and if so, does it rev high? Once running and you let off the throttle, does it die again? As of your description, I don't think it's either the IAC or the MAF. Feb 24, 2023 at 13:02
  • A common problem on these is the fuel pump. It fails to generate enough pressure and the engine stalls. You might check the fuel line pressure at the engine and see if it's in spec.
    – jwh20
    Feb 24, 2023 at 13:18
  • @Pᴀᴜʟsᴛᴇʀ2 I have to hold it down a bit initially to get it to start and then I can hold my foot on throttle and bring it down but if I let off completely it stalls. It seems to run fine once it's moving, I did just kinda hold the idle up and as bad as it is just jammed it into drive but I was able to drive home although all highway it ran fine just when I got off the exit I had to kinda hold the brake and keep the idle above like 800 or so.
    – Derek
    Feb 24, 2023 at 13:22
  • @jwh20 I considered the fuel pump but it runs once I get it started, I even drove home after with no issues other than coming to a stop I had to hold the idle up with my foot on the brake to keep it from stalling.
    – Derek
    Feb 24, 2023 at 13:24
  • 1
    I'd put a multimeter on the throttle position sensor (TPS) and see that it is operating correctly. If you have an OBDII reader which will show Live Data, you can see how it appears to the ECU. The '08 Mariner may/may not have a drive by wire setup. If it does, it could be your pedal which is at issue. Feb 24, 2023 at 13:29


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