Rich at idle...


rusty ol ranger

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87 ranger 2.9/5sp.

Ok guys i got rusty 2.0 running 100x better then before. Got it buttoned up yesterday and have put about 50 miles on it since then without any of the bullshit, weird issues i had before.

But now, it seems to go super rich at idle or if i let go of the throttle.

I suspected a TPS issue because i had screwed with that stop screw on the TB at one point (stupid i know) but its got a range of .9 up to 4.8 or so....so thats good right? Tried 3 different tps and got the same thing.

However, the black/white wire (which is ground right?) didnt seem to be grounding when i touched the black lead to it from my tester.

The only things that arnt brand new are the coolant sensor, IAT and MAP. Literally everything else is new.

The only thing is i did the 88 ECM swap to get away from the EGR/knock sensor. I have the EGR valve still on but it was a new valve...so that shouldnt be an issue right? Seeing as how if they dont get vaccuum they dont open?

I have ran codes and only got that stupid code 67.
 
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PetroleumJunkie412

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Good places to start so far. Id look at resistance on map ground, TPS ground, and an ohm reading from both temp sensors. Lmk if you need parts. 👍🏿
 

PetroleumJunkie412

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Also, that's sounding like the possibility of bad MAP. It's near impossible to get a functional aftermarket Ford MAP sensor nowadays. I have a small pile of untested ones here for 2.9. Don't need them anymore as I converted to GM (makes me feel gross typing that) MAP sensors when I went to megasquirt.
 

rusty ol ranger

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Also, that's sounding like the possibility of bad MAP. It's near impossible to get a functional aftermarket Ford MAP sensor nowadays. I have a small pile of untested ones here for 2.9. Don't need them anymore as I converted to GM (makes me feel gross typing that) MAP sensors when I went to megasquirt.
I was kinda wondering about the map myself. You sent me one in that box-o-parts lol.

But im wondering if its the vaccuum port the map draws from...heres why...

When i first started having issues last sept or so i removed the EGR valve only to find it completly plugged with a mound of soot. So hard i literally had to beat a bolt thru it to ream it out.

So, since the MAP port is directly (basically) across from that, its not out of the possibility realm its somewhat plugged to. Which would fool the map sensor into low vaccuum, which means throttle open, which means dump the fuel.

Im going to investagate as soon as i get to the shop.
 

rusty ol ranger

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May of pinned it down. MAP hose has a leak, put finger on end and blew on other and the air was going somewhere.

@PetroleumJunkie412 sent me one of those too, did same test, no leakage, installed, also the orange hose that hooks on bottom of TB came off, reattached, preliminary tests seem good. We'll see.
 

PetroleumJunkie412

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Leak in the map hose may be enough.

There's a difference in map sensors as well. Egr map has a little rectangular hole on the front for barometric correction. Non egr is a sealed unit. I think I sent one for.the non egr ECM. Maybe.
 

rusty ol ranger

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Leak in the map hose may be enough.

There's a difference in map sensors as well. Egr map has a little rectangular hole on the front for barometric correction. Non egr is a sealed unit. I think I sent one for.the non egr ECM. Maybe.
Yes there is a map sensor you sent me.

The map hose helped alot but i still get a small cloud of fuely smoke if i goose it after its been idleing. It idles pretty decent though.

I didnt know there was a difference in MAPs? So im guessing that 88 ECM wont play nice with the 87 MAP?
 

PetroleumJunkie412

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Yes there is a map sensor you sent me.

The map hose helped alot but i still get a small cloud of fuely smoke if i goose it after its been idleing. It idles pretty decent though.

I didnt know there was a difference in MAPs? So im guessing that 88 ECM wont play nice with the 87 MAP?
They will play ok together. Run a can of aerosol sea foam through that thing and see what happens. May not be rich, may just be carbon working out.
 

rusty ol ranger

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They will play ok together. Run a can of aerosol sea foam through that thing and see what happens. May not be rich, may just be carbon working out.
Didnt think about that. It is awful carboned up.
 


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