Maf sensor problems?

[Ragged out exploder31]

I have a 2001 Ford Explorer with the 4.0 I bought not running . Tried to fire it up and it would hit then die but if I unplug the maf sensor it’ll run but kinda rough and will die instantly with the touch of the gas , I have a new sensor ordered and an iac valve ordered is there anything that y’all can input to check to maybe help out my situation ? It’ll idle all day roughly until you plug in the maf and it dies instantly

 

[410Fortune]

how many miles on the 4.0?

 

[Ragged out exploder31]

how many miles on the 4.0?

208,x..

 

[Fix4Dirt]

welcome to EF! think the mad could be part of it have you cleaned it? i wonder if its leaning or richening too much?

 

[410Fortune]

it is possible it jumped time
but lets start with the basics
So the mas meter is responsible for two things in a 2000 model
it measures the incoming air that the engine is going to use, the 02 sensors then measure the air left in the exhaust after being burned and then the engine knows how much timing/fuel is needed to run properly
The mas also included the IAT incoming air temp gauge, this sensor is very important for running closed/open loop operations
So when you unplug the mas the IAT is also disconnected
Now when you unplug the mas the computer stops trying to calculate the fuel;/timing needed and instead it runs on a preset "map" since the meters it needs to measure are now unplugged.
However your engine still runs rough, stumbles and dies
So it is likely you have a few different issues going on
Instead of getting out the parts shotgun and guessing the best thing to do is eliminate possibilities
So I would:

Check fuel pressure, should be around 62 psi +/ 8 psi for a 2000
Check spark plugs, pull them keep them in order and see how they look, you can tell alot by the condition of the plugs
Next check engine codes, what codes has the computer captured during these short runs?
finally a COMPRESSION test, this would pinpoint any timing issues, cylinders that have no compression = timing issues usually on a 200K mile SOHC

 

[Turdle]

Check engine light?

Might want to scan for codes.

Thread moved

 

[Ragged out exploder31]

it is possible it jumped time
but lets start with the basics
So the mas meter is responsible for two things in a 2000 model
it measures the incoming air that the engine is going to use, the 02 sensors then measure the air left in the exhaust after being burned and then the engine knows how much timing/fuel is needed to run properly
The mas also included the IAT incoming air temp gauge, this sensor is very important for running closed/open loop operations
So when you unplug the mas the IAT is also disconnected
Now when you unplug the mas the computer stops trying to calculate the fuel;/timing needed and instead it runs on a preset "map" since the meters it needs to measure are now unplugged.
However your engine still runs rough, stumbles and dies
So it is likely you have a few different issues going on
Instead of getting out the parts shotgun and guessing the best thing to do is eliminate possibilities
So I would:

Check fuel pressure, should be around 62 psi +/ 8 psi for a 2000
Check spark plugs, pull them keep them in order and see how they look, you can tell alot by the condition of the plugs
Next check engine codes, what codes has the computer captured during these short runs?
finally a COMPRESSION test, this would pinpoint any timing issues, cylinders that have no compression = timing issues usually on a 200K mile SOHC

I’ll check all of that this evening, I’m heading toward the idea of the maf too, mainly because my buddy gave me two that he had on a parts 4.0 out of a ranger and it would actually start up and run for about two or three seconds before it’d die he has no idea if they are good or not either but it would start with his maf plugged in , but the one on the explorer when I hit it would not start unless it was unplugged

 

[Pete Deering]

I have a 2001 Ford Explorer with the 4.0 I bought not running . Tried to fire it up and it would hit then die but if I unplug the maf sensor it’ll run but kinda rough and will die instantly with the touch of the gas , I have a new sensor ordered and an iac valve ordered is there anything that y’all can input to check to maybe help out my situation ? It’ll idle all day roughly until you plug in the maf and it dies instantly

Did you scan for codes?

 

[Ragged out exploder31]

Trying to get my hand on a scan tool today

 

[Ragged out exploder31]

Probably just gonna have to buy a scanner but the maf sensor came in today and put it on and it will start now but will idle for maybe 7 seconds and will die but will take gas pedal now also

 

[Turdle]

Might be a stuck IAC valve. Cleaning it may help. Make sure to manually move the plunger while spraying the cleaner

 

[BTR]

I second what @Turdle said.

 

[jr230]

I have a 2001 Ford Explorer with the 4.0 I bought not running . Tried to fire it up and it would hit then die but if I unplug the maf sensor it’ll run but kinda rough and will die instantly with the touch of the gas , I have a new sensor ordered and an iac valve ordered is there anything that y’all can input to check to maybe help out my situation ? It’ll idle all day roughly until you plug in the maf and it dies instantly

possibly the fuel rail sensor in addition to maf. it senses fuel to injectors but heres the weird one fords about 190. local chain parts 140-150
amazon 15.00 i bought the 15 one 6 months so good and you don't need to take completely off take bolts off but not where the big hose goes in if removed you need a new gasket but with cover loose lift the drivers side up you can get in to replace it. my truck would start to run rough as it warmed uo say 5 miles then any more it would stall pull over let cool 10-15 min start again to run a few mils more just got me home. did the sensor fixed although i need to clean the maf remove from engine spray only with maf cleaner let dry. reinstall. cleaning on the engine can cause problems
update that did work the truck still running well i do have code for maf i got spray but wound up needing both hands operated on
got stitches out of 2nd hand so its on list to be done as well as a/c recharge even in winter in sw fl a/c is needed

 

[410Fortune]

2001 does not have a fuel rail pressure sensor

 

[Ragged out exploder31]

Probably just gonna have to buy a scanner but the maf sensor came in today and put it on and it will start now but will idle for maybe 7 seconds and will die but will take gas pedal now also

Finally got my hand on a scanner , got codes for o2 sensor which I already replaced and a p0113 or something that was referring to the Iat sensor temperature too high , the Iat is built in to the maf and the maf is new I just put it on . Could this be a wiring issue at the plug and causing it to ground or whatever and think the temperature is too high and killing the engine ? The maf is new but it’s a cheap one off eBay ($58) don’t know how good these engines run off cheaper parts

 

[BTR]

Finally got my hand on a scanner
p0113 or something that was referring to the Iat sensor temperature too high

Use your scan tool to log data for Engine Coolant Temperature, Intake Air Temperature, MAF, RPMs, Fuel System Status, STFTs and LTFTs for both banks, and Voltages for all four O2 sensors. Put the data in an Excel spreadsheet and keep it. Add new spreadsheets as you proceed. As you replace/clean/repair components, you'll be able to track the effects. I'd start by looking at the temperature reported by the IAT sensor with the key ON but the engine not started yet.

 

[Ragged out exploder31]

Finally got an hour or two to mess with it today, the wires on the maf looked hood but one side wire on the plug moved around , fixing to order a new plug in for it but I got a question about whether or not you can change the intake tube from an ranger or other explorer to have a separate iat sensor for it to read , or whether or not it even has separate wire to be able to add a separate sensor ?

 

[Ragged out exploder31]

Or if a faulty computer could be causing all this trouble ?

 

[Runnin'OnEmpty]

I remember Ford having a TSB on faulty MAF sensor plugs. I'd look very closely at the wire pins that you found loose. Might be a very simple fix...

 

[Ragged out exploder31]

I remember Ford having a TSB on faulty MAF sensor plugs. I'd look very closely at the wire pins that you found loose. Might be a very simple fix...

I think I remember seeing someone on here saying the two outside wires on a four wire plug has something to do with the iat if your standing in front the engine looking at it the wire on the right side is the loose one I hope that’s the problem