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1983 Bronco 5.8
14 Posts
Discussion Starter · #1 ·
So I bought my Bronco it sat for couple of years. I pulled it around started working on it but it was slow going. I replaced parts, notorious for being bad realize it wasn’t the total cure or that it’s the wrong part for the truck, or I need a gasket or this or that. So it’s order online or auto store. Example I bought the ignition switch in March after when looking for why no draw when key turned. it was in two pieces.i got the switch a few days later but it’s still in box. Well I stumbled on a 94 150 for a fair price to handle my in town short trips. So I dont have to start my dually everyday for a mile or less. Anyway as soon as summer hits 2 weeks I have lots more time and plan on doing a big tune up and fluid change. It’s a 5.0 160k on the odometer planning on new plugs, plug wires, Oil, transmission oil and filte, rear differential fluid. I know it’s like as about favorite food or sports teams. But I was wanting suggestions on what I might miss or brands that have worked for you. Example transmission was slipping realized it was low on fluid and fluid was more black than red. So even though I view it as snake oil I put bars leak dual formula in it until I can change fluid. I have put sea foam in tank again on the fence on it’s effects but hoping to get it to summer. So anything you have done the more info the better thank you.

95 f-150 4x4 5.8 e4od 05 F250 axles w/4:10's lifted/modded owned since 97 w/28K
345 Posts
i use amsoil powerfoarm to shoot down the brake booster hose whilst idling, usually kills it, shoot it down the throttle body, down the spark plug holes until it comes out, let it sit several hours. fire it up on the old plugs, it will smoke like hell but purr like a kitten. once its all smooth, then replace everything with new. its the best carbon remover ive used, another product similar is made by yamaha and is made for the same thing, murcury sells a product that works good too. amsoil once shaken up, expands like shaving cream, real thick, cleaning everything. you can/will see the carbon just melt.

i use it on jet skis, four wheelers, street bikes, side by sides, my minivan, truck, outboards, weedeater, lawnmower during the tune up, just use the old plugs first so you don't foul out a new one.

when i worked at a 5 franchise dealership, this procedure was in several tsb's for the powersports world, especially farmers who putt around a lot.

also you will want to address the fuel system, at least new fuel filter but fuel pump sock is where it actually all begins. a good injector cleaner, bitog is the website to go to to find out which cleaner works best.

a high output ignition coil in the 45k-50k volt range, and widen spark plug gap to at least 44 though and even 54 thou as per fordfuelinjections website. platinum etc. arent needed but just last longer, good ol copper cores work great and can be purchased from for around .50 to 1.50 for platinums

Super Moderator
30,683 Posts
Yo Moose,
See member Sixlitre's Tune-Up @ Sewiv's ignition upgrade and timing bump; on page 3.
"Make sure you have VERY good plug wires though. Ford's racing wires are competatively priced and so are taylor spiropros, both of which I've used with good results.
Remember to get the cheapest Autolites or Motorcraft plugs you're money will buy, as anything better is wasted on smallblock Fords.
Stab the gap at .055, I've even used .060. Then bump the timing out to 13.5 degrees from the stock 10 (after you've checked where it was to begin with).
As far as the cap & rotor they're all good, as long as they're as good as new with no arc'ing on the inner terminals and no cracks in the plastic."
Reduce weight of the Bronco and tools, accessories and ... passengers; driver's get a pass:thumbup; also, grille guards, side steps, etc.
Ensure that brakes are not dragging
Proper tire pressure, under inflated tires Increase rolling resistance
Dirty air filter causes excessively rich fuel/air mixture
Worn spark plugs cause inefficient combustion, wasted fuel
"Leaking" plug wires due to deteriorated insulation
Don't over-oil a K&N filter
Inspect exhaust system for blockage, damage
& more Items that Cost $:
COLD air intake - insulate air intake from grille entry area to throttle body.
Air Tube & Box Insulation pics in a 94 5.0; Ken used Reflectix Insulation, avail @ Lowes. etc. ST16025 - 16" x 25 feet. miesk5 Note; Ken installed the K&N® & removed the cold air intake tube that runs to the top of the radiator; but he could have installed the intake tube section later.

Source: by Ken B (Kenny's 94)

I use Ford Motorcraft parts via AMAZON; they are VG at delvy and esp pricing; I bought a $150.00 DPFE Sensor (not incl. sales tax) for $50.00 with free shipping and no state sales tax; same for the IAC sensor.
Some buy from a Ford pn on-line or local parts stores that list the Ford PN, but the ads show the PN as a reference only and the supplier may be a company off-shore. other than a Ford supplier.

High Quality Motorcraft TFI Ignition Coil Attributes
Source: by SeattleFSB (Seattle FSB) @ MSD 8227 coil problems
Many Bronco owners shop for an ignition coil by looking for the highest voltage available. But I venture to say that there is much more to look for in achieving both a quality ignition system and saving money in the long run.
For clarification, it takes approximately 10-14,000 volts to initiate the spark across the OEM spark plug gap. After the initial arc, the voltage required to sustain the arc is much less and drops off significantly. So while you may have a 48,000v coil you can't actually get that across the plug. The extra power becomes reserve voltage which compensates for worn plugs, increasing resistance in wires and carbon fouling. This increased stress can require an additional 1-5000 volts.
Fact is a higher voltage coil does not work any better, it just lasts longer due to having a higher reserve reducing heat. You cannot push more than 20,000 volts across a spark plug without bad things happening. If you were to try you would see arcing down the side of the plug, across carbon buildups at the electrode end and out any weak points in the wire insulation and connections.
The bottom line is the ideal coil output required for normal applications is about 30,000 volts. So no, your coil does not need to be 48,000v for proper ignition. The benefit would be in having enough reserve to compensate for high resistance due to a worn or altered ignition system.
This is why the Sixlitre Tune recommends a 48,000v coil and larger spark plug wires – to compensate for a substantial increase in resistance from larger than specified spark plug gaps. You are adding resistance as the spark attempts to reach ground. This in turn causes the plug wires to break down and decreases the service life of the rotor, distributor cap, spark plugs and increases the chance of spark scatter within the Distributor Cap.
Think about it, you are setting your spark plugs at a maximum gap even before wear. The higher voltage coil does not reduce stress and wear on your ignition system; it only compensates within a larger margin and then ultimately becomes dependent upon the quality of construction for survival. When opening up your spark plug gap from factory specifications you must be prepared to check your secondary ignition system annually, as opposed to about 40,000 miles with a stock vehicle, or risk performance decreases down the road.
With that being said, IMHO the Motorcraft DG470 TFI Coil is one of the most dependable 48,000v TFI Coils on the market. This is largely due to the quality in design, testing and construction. I have personally had many dependability issues with other imported TFI Coils, such as MSD. Where a Motorcraft Coil has lasted 15 years, I have went through three MSD coils in five years. Your purchase of a TFI Coil should not be totally dependent upon the voltage, but strong consideration."

EFI Performance Upgrades by inactive member Fireguy50 (Ryan) @ Ford Fuel Injection » EFI Performance Upgrades

How to pick a CAMSHAFT for EFI by Ryan M (formerly @Fireguy50)

●Lack of power, or poor fuel economy, reduced top speed.
No Code suspects are:
"Intake manifold vacuum which drops excessively with RPMs. High exhaust back pressure (greater than 1.5 psi at idle and 3 psi at 2000 rpms on most vehicles).
Passageways within the muffler, resonator or converter have become blocked or restricted. This could be caused by rusted partitions within the muffler breaking away from their original positions and blocking exhaust flow. It can also be caused by chunks of converter substrate material caught in the muffler or from excessive carbon build up in the converter. Another possible source of restriction is crushed exhaust pipes or internal air gap pipe failure. Inspect the exhaust system for crushed, bent or otherwise restricted pipes. Replace or repair as required. If pipes look good, temporarily remove the O2 sensor ahead of the converter. If symptoms are still present inspect for internal air gap pipe restriction ahead of the converter. If symptoms are no longer present, reinstall the front O2 sensor, remove the O2 sensor behind the converter and retest the vehicle. If symptoms are still present the converter is causing the restriction. Check for rich condition, excessive oil consumption, misfires or other root cause of failure. If symptoms are no longer present with the rear O2 sensor removed, the restriction is in the muffler or resonator. Inspect and replace resonator or muffler assembly as required.
Leaks in the exhaust system can affect O2 (Oxygen) storage in the converter and lead to improper O2 (Oxygen) Sensor readings, affecting the AFR (Air / Fuel Ratio) balance. Check all weld areas for cracks, especially O2 sensor ports.
Check all pipe connections for improper alignment or burnt gaskets.
Check all clamp connections for leaks.
Pay close attention to any flex-pipe in the system.
WALKER® EXHAUST SYSTEMS: Check Converter Temperature
WALKER® EXHAUST SYSTEMS: Check Converter Temperature
An infrared thermometer can be used to check the temperature of a converter to determine converter lite off. Using an infrared thermometer, check the temperature of the converter's front and rear weld rings, to ensure the converter has "lit off." Depending on their sizes, most converters begin to light off around 350º F, and are fully lit around 500º F.

Under normal conditions, the rear weld ring may reach temperatures which are as much as 150º F higher than the front weld ring. If the rear weld ring reaches temperatures in excess of 150º F higher than the front weld ring, the engine may have an emissions problem.
Excessive system backpressure can generate a converter efficiency code. Although backpressure varies with application, typically the pressure should be less than 3 psi at 2,000 rpm, and less than 1.5 psi at idle.
If a converter is operated too long at a high temperature, the substrate may "melt down" and turn into a solid mass inside the converter. The vehicle may seem sluggish as if there was a loss of power. Other causes might be: 1) upstream converter has broken up and the debris has clogged a down stream unit, 2) the support mat may have become damaged and no longer retaining the brick in the correct position, allowing the brick to shift and block the exhaust flow.

The conversion process produces heat. So, exhaust gases entering the converter should be cooler than the gases exiting the converter.

The temperature differential test measures the surface temperature at the inlet and outlet bushings of the converter. If conversion is taking place, then the outlet bushing reading should be higher than the inlet bushing reading. However, different pipe wall thicknesses and corrosion, along with different heat transfer rates, may cause inaccurate results. So, the U.S. EPA recommends that this test be used only to prove that a catalyst is good. Make sure that the engine is fully warmed up and running. Make sure the heater is OFF. Using a pyrometer or infrared thermometer read and note the temperature of the pipe just ahead of the converter inlet at the weld ring. The weld ring is the point where the inlet pipe is welded to the converter body. Read and note the temperature at the weld ring of the outlet pipe. Calculate the difference between your readings. If the outlet reading is higher than the inlet reading, you can be assured that at least some conversion is taking place. On well-tuned, newer vehicles, the catalyst can be fully functional at only a 20° F difference.

This test measures the levels of HC, CO, CO2, NOx, and O2 gases coming out of the tail pipe. Using this data, you can isolate problems under the hood and under the vehicle.

Excessively lean, or rich mixtures are beyond the capability of the catalyst to convert. Even if the converter is working to specifications, measurable levels of pollution will be noted at the tail pipe under these conditions. The validity of this test to isolate a converter problem, depends on a properly tuned and operating engine. Fortunately, a gas analyzer can first be used to locate engine problems.

Following manufacturer's instructions connect analyzer to exhaust pipe, then read and note the levels of Oxygen, Carbon Dioxide, Hydrocarbons, NOx and Carbon Monoxide produced by the vehicle. Compare your data with the Primary Causes of High Gas Levels, listed below. The chart will help isolate engine emissions control problems. There may be more than one engine related problem, in addition to a failed converter.

WALKER® EXHAUST SYSTEMS: 5-Gas Diagnostic Chart

If Chart doesn't appear, see it @
These tests are used to determine if blockages exist in the exhaust system, creating excessive backpressure. The following test can help determine the location of an exhaust restriction.

The intent of the vacuum test is to determine if there is a blockage or restriction in the entire exhaust system. It may or may not indicate converter problems. This test can be performed using any suitable engine vacuum source. After the vacuum gauge is connected to a vacuum source, readings are noted at idle and then again at 2,500 RPMs. As engine speeds vary, readings should initially drop slightly, then rise to within 2 to 3 inches of the vacuum level established at idle. A large drop of 8-10 inches of vacuum typically indicates an exhaust restriction. Erratic swings of the vacuum readings may indicate periodic blockages caused by loose components temporarily blocking the exhaust system. Remember that vacuum levels are also affected by factors other than exhaust system restriction, including valve and ignition timing.

If a vehicle fails the engine backpressure vacuum test, you can pinpoint the component in the exhaust system causing the concern by measuring backpressure at different points in the exhaust system. These measurements can typically be made through the O2 sensor ports. Start by inspecting the system for crushed, bent, or otherwise restricted exhaust pipes. Replace or repair as required. If the system passes the visual inspection, remove the most rearward O2 sensor. This sensor is typically located directly after the converter. The use of heat or penetrating oil and a back and forth motion may help if the sensor threads are rusty. Most O2 sensors use an 18mm-threaded port, so one adapter fits many applications. Install adapter in the O2 port and tighten to manufacturer specifications. Then connect the gauge hose to the adapter. Begin by reading, and taking note of, pressure at idle and at 2500RPM. On most vehicles, at idle back pressure should not be higher than 1 psi. At 2500 RPMs the reading should not be higher than 3 psi. If the readings are high at this point, the blockage probably exists downstream of the test point, which typically means it is in the muffler or resonator. If the back pressure is okay at this location, move to the O2 sensor just ahead of the converter and retest. If the back pressure is high at this point, the converter is causing the issue. If the O2 sensor ahead of the converter tests okay, then the restriction is most likely in the y-pipe assembly, or there could be an internal restriction in the air gap pipe located between the exhaust manifold and the converter."
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