CFI GURUISM

[85crownHPP]

Hello people!

I am one of the few people on this earf who thinks CFI aint all that bad.
It sure is Fords bastard child of fuel injection foolishness, but as Ive forced myself to learn about it (my last car had a carb) Ive found that it aint so bad.

It uses the SAME sensors as MPFI, the only difference is the CFI unit itself with its 2 injectors, electric choke with vacuum pulloff, and the VOTM (vacuum operated throttle modulator) wich bumps the idle up and down for various reasons.

Keep in mind I am not a trained CFI professional - all my knowledge comes from playing around under the hood, what I can get out of various usless manuals, and the EVTM for my year.

I'll use this thread to post general info and other items worthy of stickie

:slug:

[85crownHPP]

usefull things like this:



this map is specific to my 85 - it may also be correct for 84, but definitly not for 83 or 82 CFI systems that use EEC-III (has a old style ignition coil, ignition module, NO TFI)

on one quick glance at an 83 CFI, I noticed the "HT VLV" solenoid is gone, which controls the evap canister purge valve and the exhaust heat flapper valve.
On these older systems I belive the evap purge valve solenoid is found under the air cleaner.

*note*
this map is engine controls only, and does not include the other nightmare of HVAC or other vacuum systems.

[85crownHPP]

and this:

ground one terminal of the VOTM solenoid (TKICK in the diagram) to its bracket and wire the other to a + switch inside, and you now have complete control of @300 rpms of idle.

[85crownHPP]

Testing electro-vacuum controll solenoidsis easier than you think.

if you study the vacuum maps, you should see wich is the vacuum inlet and outlet. All these solenoids do is allow vacuum to pass or restrict the flow of vacuum...
some step through vacuum in increments (like for EGR) and start/stop according to feedback from something like an EGR valve position sensor (EVP)

Pretty much you test these things for ability to do thier job... use a vacuum pump tester or some tapped engine vacuum to give the solenoid some vacuum. Then, use some wire attached to the battery or a 12volt power supply to jump the solenoid.
If you used a vacuum tester, you should see the vacuum drop. If you used engine vacuum to test, you'll need a vacuum gauge on the other side to read if vacuum is passing through.

*CFI specific*

our EGRs use two solenoids - one to step-pass manifold vac to the EGR, and one to STOP throttle vac from getting to the EGR. This 2nd one uses the yellow line that goes to the CFI unit (see map)
to test this, when the solenoid is jumped, is should NOT pass vacuum through.

more to come......