86 bronco2 2.9L vacuum lines

Rbarnes08

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I have a 1986 bronco 2 2.9L 4wd. Since I bought it, the acceleration is weak and and hesitates but that isn’t the reason Im looking for help. I was removing in map sensor and efi and broke 2 lines as well as forgot the wiring of the top of the efi. Can someone show me a picture and help explain the green and red lines coming from the manifold and the wiring of their efi remote placed not under distributor. Now the truck won’t start, it cranks but it won’t start. I feel like there are some missing things in that area and other parts that the guy before had rigged so it would run. Thanks a lot!
 

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Motech

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Hello @Rbarnes08, and welcome.

Very little vacuum lines for engine controls on your BII, a much appreciated improvement over the carburetted 2.8L.

Here is the Ford diagram, which is real similar to your (missing?) underhood factory sticker, except no color.

1656467371789.png

All manifold vacuum hoses should be red, and the only green one should be from EVR (EGR Vacum Regulator) to EGR valve.
 
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Rbarnes08

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Honestly very appreciated. After hours our acronyms I was confusing myself severely. I switched the in out of the evr and to vreser and it fired. There are more lines I need to figure or sensors because it’s backfiring when the engine is hot and more than hesitates when accelerating 15-35 mph.
 

Motech

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There are more lines I need to figure or sensors because it’s backfiring when the engine is hot and more than hesitates when accelerating 15-35 mph.

That could be a lot of things, but only one in the vacuum hoses: MAP sensor, about 10:00 in the diagram.

Manifold Absolute Pressure Sensor, it measures engine vacuum and uses that to calculate fuel demand. It also does double duty as a Barometric Pressure Sensor too, so it's a very critical sensor. The most critical.


1656572105314.png

This is what it looks like new on the bench:

1656572278878.png

And this is what it looks like under your hood:

1656572782209.png

Or more specifically:

1656573423804.jpeg

That is it mounted underneath the rusty metal bracket in upper LH corner of pic.

The dedicated vacuum source is a large(ish) black nylon pipe with rubber hose on each end, starting with the 90* hose at bottom RH corner of pic, just above and to the right of the red hose.

It is important that vacuum supply is tight and strong. The rubber hose ends--especially that 90* end--soften up with age, and as your engine warms up, that sucker can and will get sucked shut. This will cause all kinds of grief as the computer believes the low vacuum signal MAP is reporting, figures you're driving way up at nosebleed altitude and leans out the fuel mix. It will choke, spit, burp, break wind, hesitate and generally cuss you out.
 
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Rbarnes08

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Okay I will go through all the sensors and wires and see what I got thanks so much
 

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