Problems with 1986 F150

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Problems with 1986 F150

86F150CA
I can't figure you how to remove the computer from my 1986 F150 4.9L.  It is under the dash but I can't release it from the bracket. I need to test it as part of a No Spark problem. This is an EEC-IV system with California Emissions if that matters.
1986 F150; 4.9L; 4 speed Manual;Feedback Carb; California Emissions (EEC-IV/TFI-IV)
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Re: Problems with 1986 F150

Sac79
Everything was disassembled by the time I got to the computer and it was 5 years ago... But I know that the bracket has a bolt above the unit and one on the driver's side behind it, the top one going into the bulkhead and the side one into the vertical mounting plate. Neither I imagine would be easy to access with everything in place. My computer is still attached to the bracket and stored in a box somewhere, I don't know if there is an easier way to detach the computer from the bracket. Sorry, hopefully someone else has helpful advice.
Rob

Eddy Myrtle '84 F150 300-6, Offenhauser C series intake, Edelbrock 1404(500cfm manual choke), EFI exhaust manifold, HEI dizzy, custom Painless harness, NP 435, NP 208, D44, 8.8"/3.08, 1.5" leveling coils, 265/75/16 tires.
Toyopet (Daily driver) '86 Toyota Pickup
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Re: Problems with 1986 F150

old55pete
In reply to this post by 86F150CA
You may not need to remove the computer from the dash. When was the last time you changed the TFI module on the distrubiter? Have you checked the rotor and cap to make sure they are not damaged in any way?

The reason I ask is the TFI module controls spark and they tend to over heat and fail.
Steve
86 Bronco, XLT, 5.0 EFI, EEC IV, AOD, IFS, limited slip front and rear, 3.08 gears, Tilt steering, factory AC
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Re: Problems with 1986 F150

86F150CA
The TFI would be my primary suspect except that I was checking the cable from the computer to the TFI and, with the ignition key in the Run position and cable to TFI disconnected, I measured 12 V from wire 4 (Run signal) to engine ground; and 7 V from wire 4 to wire 6 (signal ground).  Also, I get 5V from wire 6 (signal ground) to engine ground.  I can't find any wiring to the computer that might be disconnected/broken or shorted so I wanted to inspect the computer.  

I won't be surprised if the TFI module is bad but I want to eliminate the computer first.
1986 F150; 4.9L; 4 speed Manual;Feedback Carb; California Emissions (EEC-IV/TFI-IV)
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Re: Problems with 1986 F150

86F150CA
First prize goes to old55pete.  I had a discarded TFI from my mechanic and installed it.  Truck started in less than one revolution!  It now has a new TFI module.  Now I can get back to the original problem, failed Smog. It is still a mystery to me why the TFI failed so suddenly.

Thanks to everyone.  I will be back with more questions.
1986 F150; 4.9L; 4 speed Manual;Feedback Carb; California Emissions (EEC-IV/TFI-IV)
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Re: Problems with 1986 F150

Gary Lewis
Administrator
Congrat's!!!!
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI