The fuel economy on my car has been slowly, steadily decreasing for 2-3 years. Damn near everything related to the fuel injection system has been replaced in that time, and I even got a fully built engine from Metric Mechanic in there. If anything, after the year or so that the car sat when engine stuff was being worked out, gas mileage was considerably worse with the new engine, which was not supposed to be the case.
ALMOST everything in the fuel system was replaced. Some of the vapor containment hoses are probably original, and I didn't ever really get to replacing the fuel feed/return hoses in the rear of the car since they looked like a giant pain in the ass to get at. For the last few months I have been faintly smelling raw gas if I get my nose up under the car near the fuel filter. It was never wet back there, but it almost looked like fluid had been weeping or spraying at the outlet of the filter (which made no sense since a plugged filter would leak at the inlet...maybe it was just road crud sprayed on) and maybe down the side of the tank. I replaced the filter in mid-2010, so it was probably time to replace it anyway.
Today I noticed a gas smell when I was sitting at a light. When I pulled in to the parking lot and looked up in there, the high pressure hose that connects from the tank hard line to the filter looked shiny / wet. Fuuuuuuu. So I drove it back home (took a 3 hour "lunch" to work on it this afternoon lol). Reaching up in there, the hose clamp that holds it to the tank hard line seemed loose, at least enough so that I could rotate the hose on the barb. Hmmm. I assume that I always had a hard time seeing any leaky stuff since gas evaporates fast, particularly when it is warm out, which is most of the year here.
Thankfully, I JUST bought a full set of fuel/vapor/vacuum hoses and 3m of 8x13mm high pressure fuel line, as well as a new fuel filter. Getting the hose off of the tank's hard line was a PITA, and based on how it was facing, it must have been the original hose since I had to loosen it 15° at a time with needle nosed pliers until I could get the hose off. Seemed like it had been put on there with the tank off of the car, which as far as I am aware has never happened since it was originally built. The hose itself was cracking at the ends and had some surface cracks in the middle. A leak up there was probably more due to the loose clamp, assuming that was what was going on, or maybe the inner rubber was damaged and fuel was leaking out between the two layers. Getting the new feed line back onto the tank's hard line outlet was sort of a pain since you have to get it seated and clamped more by feel than by sight, but it all seems to check out and at least I can get a nut driver on the clamp in the future. All of the other fuel feed/return lines back there got replaced, as well as the filter and hose clamps. I also replaced the long rubber return line, which was super easy actually...just had to pop the rear seat and slide the old one out with the new hose duct taped concentrically to it so pulling out the old one snaked the new one into place!
HOPEFULLY my gas mileage improves dramatically as a result of this. There is basically no rust anywhere on the car that I can find, so I would assume that the tank itself is good up by the hard line. Has anyone had the high pressure hard line fail for any reason?
Here are some tips for anyone that needs to deal with the fuel system:
Depressurizing the system
The fuel system will stay at a few dozen PSI after you turn the car off. If you loosen a hose on the feed side, you are going to get a lot of fuel coming your way, possibly spraying into your eyes. To easily depressurize the system, start the car, go under the hood and yank out the fuel pump relay up on the firewall (blue one in the middle). Let the car run until it dies. This way, you'll only have to deal with a few ounces of fuel draining out if you are down by the filter, and less if you are working up on injectors or something.
Dealing with the high pressure outlet hose
This hose is sort of a pain in the ass to deal with. It is the one that feeds from the tank's hard line to the fuel filter inlet. To effectively get at it, you need to remove the filter and the big bracket thing that holds the filter and disconnect the other hoses around there. The hose clamp holding the line on is up in there and marginally visible. The head on it takes a 5mm nut driver. In my case, the body was positioned so that the head was facing up, and the only way to loosen it was 15° at a time with some needle nosed pliers. Once loosened, I wiggled it off. Don't wail on the hose too hard because you could bend/kink/break the hard line coming off of the tank. To get the new hose on, I inserted/removed the new hose end on the old fuel filter's barb 5 times to stretch it a little and make it go on easier. You want to use the OEM style (small) hose clamp because space is very limited up in there. Make sure that the head points down'ish so that you can just use a nut driver to tighten it. You will need to feel where the clamp is on the hose...behind the bulge on the barb but not hanging off the end of the hose. Also make sure that the clamp isn't hitting the chassis or tank since that could lead to problems. I'd say that you should cut the new hose to be at least 10cm longer than the old one that you removed to start with. Once you get the filter bracket and filter re-installed, cut the new hose to the optimal length so that the bend radius is small enough to keep the hose clear of the chassis but not kinked/collapsed. I found that aircraft- / tin-snips work great on the fuel hose...clean cuts without crushing it.
The right order to replace filter hoses
Leave the old fuel filter outlet hose attached to the hard line on the chassis with the open end (the one that was connected to the filter outlet) pointed down. When you are up in there banging around you are knocking crud and stuff around. Once everything else is settled, reattach it (or replace it) and be careful not to knock crap into it. Fuel injectors don't do well with sandy sediment!
Replacing the long rubber return hose
This is easy. It's the "other" hose that connects to the fuel pump/sender bracket and runs from there to over near the fuel filter. Remove the rear seat bottom and the two black covers. Disconnect the ends of the old return hose and pop them off of the barbs. Get your new hose (8x13mm, start with a 2m length and trim once in place) and use some tape to attach one end of it to the old hose's end up inside the car. Carefully yank the old hose out from under the car and it'll pull the new one into place. There are some foam pads attached to the old hose, so be careful not to rip those and you want to put them back where you found them once the new hose is in. Once the new hose is connected to the tank return inlet, go under the car and trim off the excess so that the new hose fits like the old one.
Safety / I take no responsibility for you burning your house and car down or worse
First, before exposing ANYTHING in the fuel system, disconnect the battery. This goes doubly for work under the hood. Many of us have accidentally tagged the terminals on the starter with a wrench and seen sparks shower out. Also, do fuel system work OUTSIDE and down-wind from any part of your house with a pilot light from a water heater or interior heater. If you absolutely must do it inside, turn off the pilot light at the water heater and get a big box fan blowing any fumes out of the garage. Also avoid having a trouble light nearby when you are going to loosen a fuel hose and have gas spill out. At least turn it off before then since those cheap contact switches will spark internally. Keep a fire extinguisher and/or garden hose nearby at all times. Seriously, gasoline is no joke and it is my least favorite thing to work with. Unless it involves matches and a big open space or something, then it is fun, but not when it involves my car and house.
When you are done with whatever it is that you are doing, get the car started and do a thorough inspection for leaking fuel.
°°°°°
How do I get the degree (°) symbol? Easy. Hold Alt and press 0176 on the numpad. It ONLY works with numeric input from a numpad, not the top row of numbers. Sucks if you are on a laptop keyboard.
ALMOST everything in the fuel system was replaced. Some of the vapor containment hoses are probably original, and I didn't ever really get to replacing the fuel feed/return hoses in the rear of the car since they looked like a giant pain in the ass to get at. For the last few months I have been faintly smelling raw gas if I get my nose up under the car near the fuel filter. It was never wet back there, but it almost looked like fluid had been weeping or spraying at the outlet of the filter (which made no sense since a plugged filter would leak at the inlet...maybe it was just road crud sprayed on) and maybe down the side of the tank. I replaced the filter in mid-2010, so it was probably time to replace it anyway.
Today I noticed a gas smell when I was sitting at a light. When I pulled in to the parking lot and looked up in there, the high pressure hose that connects from the tank hard line to the filter looked shiny / wet. Fuuuuuuu. So I drove it back home (took a 3 hour "lunch" to work on it this afternoon lol). Reaching up in there, the hose clamp that holds it to the tank hard line seemed loose, at least enough so that I could rotate the hose on the barb. Hmmm. I assume that I always had a hard time seeing any leaky stuff since gas evaporates fast, particularly when it is warm out, which is most of the year here.
Thankfully, I JUST bought a full set of fuel/vapor/vacuum hoses and 3m of 8x13mm high pressure fuel line, as well as a new fuel filter. Getting the hose off of the tank's hard line was a PITA, and based on how it was facing, it must have been the original hose since I had to loosen it 15° at a time with needle nosed pliers until I could get the hose off. Seemed like it had been put on there with the tank off of the car, which as far as I am aware has never happened since it was originally built. The hose itself was cracking at the ends and had some surface cracks in the middle. A leak up there was probably more due to the loose clamp, assuming that was what was going on, or maybe the inner rubber was damaged and fuel was leaking out between the two layers. Getting the new feed line back onto the tank's hard line outlet was sort of a pain since you have to get it seated and clamped more by feel than by sight, but it all seems to check out and at least I can get a nut driver on the clamp in the future. All of the other fuel feed/return lines back there got replaced, as well as the filter and hose clamps. I also replaced the long rubber return line, which was super easy actually...just had to pop the rear seat and slide the old one out with the new hose duct taped concentrically to it so pulling out the old one snaked the new one into place!
HOPEFULLY my gas mileage improves dramatically as a result of this. There is basically no rust anywhere on the car that I can find, so I would assume that the tank itself is good up by the hard line. Has anyone had the high pressure hard line fail for any reason?
Here are some tips for anyone that needs to deal with the fuel system:
Depressurizing the system
The fuel system will stay at a few dozen PSI after you turn the car off. If you loosen a hose on the feed side, you are going to get a lot of fuel coming your way, possibly spraying into your eyes. To easily depressurize the system, start the car, go under the hood and yank out the fuel pump relay up on the firewall (blue one in the middle). Let the car run until it dies. This way, you'll only have to deal with a few ounces of fuel draining out if you are down by the filter, and less if you are working up on injectors or something.
Dealing with the high pressure outlet hose
This hose is sort of a pain in the ass to deal with. It is the one that feeds from the tank's hard line to the fuel filter inlet. To effectively get at it, you need to remove the filter and the big bracket thing that holds the filter and disconnect the other hoses around there. The hose clamp holding the line on is up in there and marginally visible. The head on it takes a 5mm nut driver. In my case, the body was positioned so that the head was facing up, and the only way to loosen it was 15° at a time with some needle nosed pliers. Once loosened, I wiggled it off. Don't wail on the hose too hard because you could bend/kink/break the hard line coming off of the tank. To get the new hose on, I inserted/removed the new hose end on the old fuel filter's barb 5 times to stretch it a little and make it go on easier. You want to use the OEM style (small) hose clamp because space is very limited up in there. Make sure that the head points down'ish so that you can just use a nut driver to tighten it. You will need to feel where the clamp is on the hose...behind the bulge on the barb but not hanging off the end of the hose. Also make sure that the clamp isn't hitting the chassis or tank since that could lead to problems. I'd say that you should cut the new hose to be at least 10cm longer than the old one that you removed to start with. Once you get the filter bracket and filter re-installed, cut the new hose to the optimal length so that the bend radius is small enough to keep the hose clear of the chassis but not kinked/collapsed. I found that aircraft- / tin-snips work great on the fuel hose...clean cuts without crushing it.
The right order to replace filter hoses
Leave the old fuel filter outlet hose attached to the hard line on the chassis with the open end (the one that was connected to the filter outlet) pointed down. When you are up in there banging around you are knocking crud and stuff around. Once everything else is settled, reattach it (or replace it) and be careful not to knock crap into it. Fuel injectors don't do well with sandy sediment!
Replacing the long rubber return hose
This is easy. It's the "other" hose that connects to the fuel pump/sender bracket and runs from there to over near the fuel filter. Remove the rear seat bottom and the two black covers. Disconnect the ends of the old return hose and pop them off of the barbs. Get your new hose (8x13mm, start with a 2m length and trim once in place) and use some tape to attach one end of it to the old hose's end up inside the car. Carefully yank the old hose out from under the car and it'll pull the new one into place. There are some foam pads attached to the old hose, so be careful not to rip those and you want to put them back where you found them once the new hose is in. Once the new hose is connected to the tank return inlet, go under the car and trim off the excess so that the new hose fits like the old one.
Safety / I take no responsibility for you burning your house and car down or worse
First, before exposing ANYTHING in the fuel system, disconnect the battery. This goes doubly for work under the hood. Many of us have accidentally tagged the terminals on the starter with a wrench and seen sparks shower out. Also, do fuel system work OUTSIDE and down-wind from any part of your house with a pilot light from a water heater or interior heater. If you absolutely must do it inside, turn off the pilot light at the water heater and get a big box fan blowing any fumes out of the garage. Also avoid having a trouble light nearby when you are going to loosen a fuel hose and have gas spill out. At least turn it off before then since those cheap contact switches will spark internally. Keep a fire extinguisher and/or garden hose nearby at all times. Seriously, gasoline is no joke and it is my least favorite thing to work with. Unless it involves matches and a big open space or something, then it is fun, but not when it involves my car and house.
When you are done with whatever it is that you are doing, get the car started and do a thorough inspection for leaking fuel.
°°°°°
How do I get the degree (°) symbol? Easy. Hold Alt and press 0176 on the numpad. It ONLY works with numeric input from a numpad, not the top row of numbers. Sucks if you are on a laptop keyboard.
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