I may have to wait till I get to town to get the MAF off. I don’t think I have a T20H torx bit with the hole in it. Hopefully it’s the MAP.
As already mentioned, try unplugging the MAF sensor and driving it around the block…
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MAF sensor, the battery heats a resistance wire, sort of like a toaster, then the temperature of the wire is measured to assess the amount of air flow. If the circuit continued to heat that wire even though the engine was off, that could discharge the battery pretty quickly. There should be various built-in circuit protections to prevent that from happening , but maybe something has failed, relay stuck in the “on” position, etc.
The MAP is probably used in conjunction w/the MAP to decide how much fuel to inject. A fault with it could cause a battery discharge too, but much less likely than the MAF. My Corolla still runs pretty good even if the MAP is unplugged, although the CEL immediately turns on. The engine computer must figure out how much fuel to inject another way, probably uses the engine rpm.
Do you have a repair manual? There’s probably a way to do a basic test on both sensors using a DVM. Both sensors likely require a precision voltage input. Since that’s something in common with both sensors, a problem with that should be considered as well. There’s probably a simple DVM test for that too.
You can also do the tap test. Wrap it with a screwdriver handle to see if anything changes. If it does, bad but if it doesn’t still could be bad. They are under $50 now though.
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I swapped MAP sensor from my lesabre. Drove 5 miles. Seemed to run great but when in idle it was surging a little. I disconnected the MAF it got better.
I left it disconnected for now.
Tested the old MAP by driving the u lesabre for 70 miles. Not a problem. So it’s not the MAP.
Got the special “safety” torx to remove MAF. Will swap tomorrow.
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I get the impression you are grasping at straws. You may get lucky on a parts replacement, but if not suggest to not continue down this path much longer. Instead pay a shop do a proper diagnostic. Other possibilities for a P0101 include problems with the TPS, IAT, ECTS, RPM sensor (crank sensor presumably), EGR position sensor, EVAP purge valve, MAP, among others. Once you get the diagnostic complete, you’ll have something to go on, which parts to replace, etc.
Once you get the MAF sensor removed, you could measure its resistance I suppose. Althought I doubt there’s any spec to compare against.
I put the MAF from the lesabre on the park. It ran perfect. Idle didn’t tv surge a bit.
I had a diagnosis done. It showed MAF OR MAP. So the logical first step seemed to be to swap the parts I already have.
Perhaps it’s a coincidence that it’s running perfectly with the change of sensor.
Sounded like a MAF sensor to me from the get go…
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That’s what I did when I had two 3800s. Just swapped one as a test to confirm. That’s when they were $300.
Why is it if the MAF is bad you can just disconnect it and run it like thst and it runs better? I would think with it unplugged would be just as bad as a bad sensor.
The data is incorrect when a bad/dirty MAF is plugged in, so now with the MAF unplugged the computer will use a back up or preset number and idle the engine up as well as run rich to keep from damaging the engine… Sometimes it will die when idling in gear like at a stop light, so you either have to put you foot in it a little or shift to neutral to keep it running… But it is used to get you home and NOT good for long term use…
So knock on wood, every time I have had a MAF code and the engine wouldn’t stay running long enough or at all to move it a little ways and I unplugged it, it was a bad MAF sensor… under normal circumstances…
Just gave it a 50 mile test drive. Ran good. When home I let it idle for 5 minutes. No surging idled good.
It has started hard when I fill gas tank up. Have to hold it the floor to start and get moving. After a couple blocks it is not a problem. I was hoping this sensor change would fix that. It’s not a big deal. It runs good otherwise. Perhaps it’s the gas cap. I tried starting without cap on didn’t help.
Otherwise case is closed.
As for a older case on a lesabre trunk switch inside car not working but working on the key button. Somehow I hit the switch in trunk. Recently I noticed my this. It works now.
That usually indicates there’s a problem with the purge valve leaking.
Tester
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Sounds like fuel pump going south. Put a hammer or 2x4 in the trunk to bang on the tank.
Or replace the fuel pump.
Since the purge valve is not bringing up a code for it I should assume that’s not causing the hard start on a full fill up. At all other times it starts fine. I’ve had it stall however after starting it within a block or 2. Once you get that far it’s no longer a problem.
If the pump is going bad will jI get other signs as it gets worse or just one day not start.
No.
A stuck open purge valve may not cause the Check Light to turn on right away.
Tester
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If purge valve was stuck would it run and start as it should 99.999% of the time but only when full filled gas tank? Or does a full tank cause it to be stuck for a very short time?
Do you top it off when fueling/filling up, or return the nozzle once it clicks and the pump stops pumping??
I’ve never had a purge valve failure but have had fuel pump issues so couldn’t really testify to the difference. I have had a no start after getting gas and fuel pressure zero, not running, until much banging on the tank jarring the pump to run again.
So yeah if you don’t hear the pump running when turning the key, that’s a major clue. But random stalling, etc. they are just little electric motors that work hard, get stuck, and wear out.