Speed density idol surge?

[cobrarwanab]

My buddy called me up and said he has a constant rpm surge or high/low fluctuation at idol. It's on a fox stang and he's bringing it buy tomorrow. He said their are no vacuum leaks and timing is set perfectly. Anybody have a heads up on a common solution to this problem? I haven't done much work with speed density other that convert to mass air. Also can he alter a mass harness from a 3 pin to work with a 4 pin obd2 mass?

 

[Sean]

could be the map sensor is bad. I would check the vacum lines and the base throttle setting.

 

[cobrarwanab]

could be the map sensor is bad. I would check the vacum lines and the base throttle setting.

Thanks, Is their a way to test the map without an oscilloscope or scan tool? also, how to check the sensor holds vacuum?

 

[Sean]

Not really.

 

[1qk50]

Check the IAC, pull it off, clean it.

 

[Pro Shifted]

Sounds like a lean roll. First i would verify fuel pressure.

 

[Pro Shifted]

Then I would look at the coolant temp and air temp to make sure these are reading correctly. This is a stocker right?

 

[igotaneed4speed]

If you put some D.E.F (aka Urea) in it everything will be all better.

 

[Pro Shifted]

If you put some D.E.F (aka Urea) in it everything will be all better.

Maybe for a while.

 

[igotaneed4speed]

Maybe for a while.

Do you have a BFH I can borrow to make some minor adjustments to my FTIR cuz its a pos

 

[Pro Shifted]

No BHF?? but i got a BMFBPH.

 

[igotaneed4speed]

http://www.granatellimotorsports.com/pdf/manuals/manual37.pdf


Speed density to mass conversion...

you dont have to buy the harness just make one up, or you can buy the 4 wire pigtail from ford and just extend teh wires i think its like 25 bucks..

 

[Pro Shifted]

http://www.granatellimotorsports.com...s/manual37.pdf


I've been to Joey's house. Does that get me a dot?