Intro: How to Perform a Three Step Fuel Service + How to Make a Tool
the three step is a common service procedure performed at almost every shop out there, however it is not cheap. a quick call around were i live netted prices between 120-175. it isn't a hard process but it is a time consuming one. for less than $30 I performed something i believe to be almost the same thing.
this is my first instructable, please leave feedback and let me know how i could make it better!
also the standard disclaimer applies, fuel is flammable, an irritant, and so is the cleaner you choose (or at least I hope so)
and air pressure can be dangerous if misused,
Step 1: The Goods
first gather the required parts.
1x air fitting
2x 1/4 to 3/4 bung
2x 3/4 to 1" reducer
1x 1" by 10" pipe
1x brass barb fitting in what ever size fuel hose you decide you need
2-3 ft high pressure fuel hose rated for at least 70 psi
2x hose clamps
1x Teflon tape
Step 2: Gather Some Tools
grab some tools. those tools include,
fuel line disconnect tool
very large chanel locks or second pipe wrench
portable air tank or compressor and airline
Step 3: Ok So Make the Tool
its easy. teflon the fittings and thread the parts together until it looks something like what i have made
Step 4: Step One... I Mean Err Four
the first step in the first part of the three step is to run the engine until it is at operating temp
Step 5: Pop the Hood
.... do it, its the only way to continue on
Step 6: Pull the Fuel Pump Power Conection
with the engine warm and running pull the fuel pump power link be that relay, fuze or even the connection on the pump. wait until the engine dies, crank it over a few more times to be sure, and go ahead and move on to the next step
Step 7: Finish Dumping System Pressure
on my vehicle i am lucky enough to have a fuel pressure test port on the fuel rail. if you have one of these start by depressing the valve in the port with a screwdriver wrapped in a rag to soak up the fuel. finish up by disconnecting the fuel line to the fuel rail.
if you have a fuel rail where you have a thread in fitting, they usually have a rubber line you can tap into up stream.
Step 8: If Your Vehicle Is Equiped With a Regulator and or Fuel Return Hose...
vehicles that are so equipped are a little more difficult to clean. on an open loop fuel system, ( has a return hose) the fuel return hose needs to be capped off. i use a thick vacuum cap. a bolt and hose clamp on a rubber return line can also work (be sure to isolate the fuel rail side) alternatively you could get a fancy hose clamp pliers from a tool warehouse and pinch the line off . the other important step is to remove the vacuum hose from the fuel pressure regulator and plug or pinch the hose off. if when you apply pressure to clean the system and fuel leaks out of the vacuum port of the fuel pressure regulator, the diaphragm inside the fuel pressure regulator is shot and needs to be replaced
Step 9: Hook It Up
now that you have the fuel line disconected, hook up your new tool
Step 10: And Fill It
i chose to open mine to fill it, but you could fill it through one of the fittings
Step 11: And Now a Word About Fuel System Cleaners
i made my own mix of berryman b12 and marvel mystery oil. straight mmo runs the risk of clogging cats and ruining oxygen sensors if used in this manner. if used in a regular manner its fine. also berrymans b12 seems really dry. mixing the two 75/25 should be safe, and in my case it was, however ymmv. any brand name cleaner should work just fine
Step 12: Fill Your Tank
i pumped my air tank up to fuel system operating pressure, 55 psi. if pressure is unknown a good starting point is 30-45psi. a better way is to start at 30 psi and regulate the pressure up until a smooth idle is achieved. KEEP ENGINE SPEED AT IDLE. i can not stress that point enough. if you run the engine faster than 1000rpm for an extended period of time you run the risk of melting your catalytic converter! let your engine float along and let the cleaner do its job. there isnt a whole lot of volume to displace, something like 12 cubic inches, so one could make do with a bike pump and a small pressure chamber
Step 13: And Hook Up Your Tank
yeah hook it up and start flow. if a compressor and shop air is available be sure to regulate it down to 30 -50 psi
Step 14: Start It Back Up
and start your engine
Step 15: When It Stalls Out
either fill it back up and repeat steps nine through thirteen, or disconnect everything, re install the fuel pump power connection( a relay in my case), and reinstall the fuel line. and move on to the next step. if you decide to put the tool away be sure to coat the threads where it breaks apart to fill with a wd or grease or antiseize
Step 16: Remove the Air Intake Hose
Step 17: Spray Out the Throttle Body
get in all the ports and down in the manifold a little bit
Step 18: The Last Step in the Three Step...
is to suck cleaner through a vacuum line. there are better tutorials and this isnt the way i prefer to do it. i use a vac tee and a few feet of vac line to meter it in. but this was quick and easy. before you finish make sure to kill it so you can soak the pistons for a while. resist the urge to drive it right away, let it sit for at least an hour
Step 19: Pour It In
most shops at this point will also pour a fuel cleaner in the tank. i opted not to do it at this point, I chose to do it the next time i fill up. i have also chosen a non conventional cleaner to see how it does. the idea is sound if mixed in proper amounts and i may do another instructable once i feel there is enough data to submit. for the time being you could read about it here
i am in no way affiliated, but his ideas seem sound to me. use your own judgement .
Step 20: If You Have a Cel Now Is the Time to Take Care of It
from running the system lean i had a lean code and a couple of misfire codes. cleared them out and it was good as new. if you dont have a code scanner you can pull the negitive cable for 30 min or drive up to your local parts store and ask to borrow theirs.
Step 21: Other Thoughts
and thats it. you now have a tool capable of cleaning your injection system more completely than any fuel injector cleaner run through the gas. if i were to do it again id put a ball valve in and i would consider putting in a pressure tank on the side of it so i can pressurize it with a bike pump and make it portable. in the end however i decided to make it as simple as possible for proof of concept.
i could also find some fuel pressure adapter fittings and not even have to disconnect the fuel line. however it is more dangerous to do it that way as it could back flow the system and cause damage
it does have more upper end, to what end i have no idea, however an automatic jeep using a Chrysler truck trans wont let me explore that too much. fuel economy went up by one to two in most cases( steep hills went down by one. i feel this proves that i have more fuel being injected, and thus more potential for power to be produced. the old butt dyno seems to concur) and it has stabilized out to an even 22mpg (from a bouncy 20-22) or so on my flat Midwestern highways. all and all not bad for a 15 year old truck with a tired engine, a power sucking automatic trans, full time four wheel drive, and 3.73 gears
i feel the $27 i spent for a tool i will reuse in the future is well worth my time and money