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Hello,
i´m new to the forum, and i´m very happy i found it. I´ve read several FAQs and topics here but still have a few questions.
A good friend of mine just bought a '86 F150 with inline 6 engine, and he asks me to help get his car running.
I´ve taken a few pictures and i would be happy if someone could tell me what is what, or just a few comments.
Especially i want to know what ignition is this exactly, is there a resistor wiring for the coil, and what type of ignition wiring fits? are there any electronic sensors?
This is the car:
and now the questions start:
is 1) the capacitor from the ignition distributor? what type of distributor/ignition is this?
next, what is this for?
and this is at the back of the carb, there´s a cable from the ignition coil to it? I thought this is a bi-metal for running the engine rich when it's cold?
Thanks for your help, hope to get this cool car running
From 1984-1986, the 4.9L six cylinder had what is commonly referred to as a "feed-back" system. The Ford engineers used this to be able to meet emissions standards as well as increase fuel mileage just before changing to fuel injection in 1987.
There is a computer located under the dash near the ash tray. The computer gets input from an Oxygen sensor located in the exhaust manifold, a thermocouple/probe for water/coolant temperature located in the thermostat housing, and a MAP sensor [measures manifold pressure/vacuum] located near the battery. The computer then controls the carburetor via a solenoid which can control air/fuel ratio to a limited degree. Also controlled by the computer is the distributor, since the distributor has no advance weights or vacuum advance.
When this "feed-back" system is working correctly, it actually is quite nice, but when something goes wrong or is tampered with, the computer goes into a "safe" mode [as if a sensor has failed or been deleted or vacuum hoses are broken, etc. The "safe" mode locks the initial timing at ~10 degrees before TDC and causes the carburetor to go rich. You end up with poor performance and horrible gas/fuel mileage.
The air cleaner assembly shown in the photos is not original, so I imagine other things may not be original, too. Also, the ignition coil is not original.
#1 is used to help prevent ignition related radio interference.
#2 is the electrical connection/module part of the "feed-back" distributor. Note that there is no vacuum advance canister.
#3 is a gang of solenoids used to control functions such as EGR valve, etc. Note the hard plastic vacuum lines which appear to be original [29 years old]. These harden over time and with flexing, crack and contribute to vacuum leaks. It is recommended to replace them with new rubber lines.
#4 appears to be the choke heater.
If where the truck is located has emission testing, all of these systems have to work together. My truck is a 1986 with 4.9L engine. It has been retrofitted to be like a pre-emission vehicle... use the search feature and type in Duraspark conversion.
The 4.9L engine tends to shake loose the two nuts which hold down the carburetor which creates a vacuum leak and causes the engine to run poorly. Grab the air cleaner [engine not running for safety] and gently rock the cleaner back and forth to see if there is movement, indicating that the carburetor is loose.
Also, over time, the (5?) small screws which hold the carburetor halves together tend to loosen. The carburetor has to be removed to access the screw heads which are on the bottom of the carburetor.
By the way, these engines were originally equipped with two catalytic convertors.
Well, probably too much information, but perhaps this will get the conversation going.
Wow, thanks a lot, that helps me!
Meanwhile, i got the car running, ignition coil was bad, but engine shakes still a lot.
Do you have a picture of the map sensor near the battery?
Wow, thanks a lot, that helps me!
Meanwhile, i got the car running, ignition coil was bad, but engine shakes still a lot.
Do you have a picture of the map sensor near the battery?
Great post 1986F150six ...
Did you replace the coil with another round one or the square style?
Was the replace coil rated for 12 volts or does it require a ballast resistor?
What is the voltage at the coil positive at idle?
If you have access to a timing light you can check to see if the engine has any advance.
Did you replace the coil with another round one or the square style?
Was the replace coil rated for 12 volts or does it require a ballast resistor?
What is the voltage at the coil positive at idle?
If you have access to a timing light you can check to see if the engine has any advance.
JIm
Thank you, Jim. I receive far more assistance than I can provide. That is what I love about our forum!
Picture #2 looks like the stock 1986 EEC-IV controlled TFI distributor. That is the ignition module bolted to the side of it. That particular distributor is NOT compatible with an aftermarket carburetor and/or ignition coil. I see an aftermarket round canister-style coil, but you should have a square "E-coil" to go with that distributor.
Like 1986F150six said in his post, you have an EEC-IV computer-controlled feedback system. Although they work very well when all of the correct components are present and functioning properly, that particular system is not "mod friendly." You need to have the correct feedback carburetor, TFI ignition system, all emission components, and all engine sensors in place and working or else it will never run right.
did some research, tried a few things and still unhappy, so consider to do the following:
offy c intake, 4bbl carb/450cfm, DUIi street/strip distributor, efi exhaust manifolds.
new electrical wiring, delete all emission and old ignition stuff.
mainly c intake because of availability and ive heard that it's simpler to install than a dp intake. Am i right?
someone got hints especially for installing the stuff?
heard something bout the DUI distributor, oil pump pinion connection?
did some research, tried a few things and still unhappy, so consider to do the following:
offy c intake, 4bbl carb/450cfm, DUIi street/strip distributor, efi exhaust manifolds.
new electrical wiring, delete all emission and old ignition stuff.
Good plan. Except I would run the Offenhauser DP intake and a Holley 390 cfm carburetor. You will get very good results with that combination.
It is hard to tell from the photos, but is the carburetor the feed-back as original? It will have an electrical solenoid as an integral part of the design. It is located on the driver's side.
It will look like this:
http://www.ebay.com/itm/NOS-FORD-REMAN-Carter-YFA-W-feedback-Carburetor-E3PZ-9510-BDAX-Rebuildable-Core-/331639461392?hash=item4d37409610&vxp=mtr
Is the Oxygen sensor still connected? It is located on the exhaust manifold just above the outlet.
With the open air filter element, the engine likely will stumble when cool.
The original feedback carb works just fine with the duraspark setup. Once you dismantle the carb to refresh it you realize that the "solenoid" is just an air valve. With it unplugged and left on the carb you can set your idle mixture and timing by ear and all will run very nicely.
