mk1 fuel tank removal

[Racer23gt]

i need to remove the gas tank and replace the fuel pump in my 85 mr2..this is my first car and i dont have the money to pay someone to do this task..so i am taking it into my own hands...and im no mechanic....i have the repair manual but the pictures are so small and distorted and the instructions are like reading a foreign language..so i was wandering if anyone had any links to write-ups or any websites that might explain it a little more simply than having to switch back threw chapters of a manual. Ive got the plastic gaurds off the bottom of the ride..ive got the middle console out and the fuel sender and fuel pump wires disconnected...now im guessing the hard part...any advice or links would be greatly helpful and appreciated..like i said i would love to get this car out on the road..it deserves to be Aw'ed upon hah.

[Jackstand Queen]

Joking . . . . take hose on exhaust of running car . . . . place other end of hose in . .. mouth. Joking


By the end of a gas tank removal and install . . . you will think that I wasn't joking. Be mentally prepared for a real work out.

Some pitfalls with gas tank removals are bent fuel (metal) fuel lines. Use a light and make sure every single vacuum line and gas line is disconnected.

Be prepared to replace both the gas filler tubes and gas vent tubes. Gates makes one with a 90 degree bend in it, that fits.

Be sure you are working with a tank that is almost empty. A half full tank is too heavy period.

Disconnect the battery by its negative terminal .. . . first thing you do. The Smoking Lamp is out . . an old navy ... . way of saying no smoking.

[YellowJacket]

Originally Posted by hpmaxim
In order to remove the fuel tank, you should:

1) Remove center console in car and disconnect the two electrical connectors.
2) Remove three underbody covers and rear plastic tray cover on firewall.
3) Drain fuel tank. If you have an 87+ there is a valve in the tank you can open to drain it, if not you will need to remove the fuel sensor and pump or siphon fuel out.
4) Disconnect fifty bazillion hoses (actually 6 or 7: fuel filler hose, fuel vent hose, fuel line, return line, two charcoal vent hoses, and I might be missing something)
5) Disconnect two straps.
6) Lower tank out

If you skipped any of these steps, its not going to come out, and if it does, you've probably broken something while removing it (or spilled fuel all over the place).

In all honesty, the hard part is contorting your hands and arms to get at the fuel lines (both on installation and removal) the rest is pretty easy, although tedious (I can't tell you how many fasteners on the underbody trays I had fail on me). If you don't have a gas drain, its not that big of a deal. Take the center console off (you have to do that anyway) and remove the the fuel gauge assembly and then pump the fuel out from there. Don't try to remove the tank with fuel in it, it'll be a mess. Having a helper (especially when actually removing/installing the tank) makes things easier.

Pull center console, disconnect electrical connectors (a 2-pin and a 3-pin). Drain tank (if you have an 87+ there should be a drain valve, otherwise pull the fuel gauge and pump fuel out from there).

Remove all three plastic underbody trays on the bottom and the black plastic one attached to the firewall.

Remove all the hoses (there are a bunch of them). There's the fuel filler, fuel vent, line to filter, return line, and two evap hoses. The evap hoses are very hard to get at, and I did't remove them and they just dropped off fine. I think newer cars had more hoses.

Remove e-brake bracket and other brace blocking the tank. You shouldn't need to disconnect the e-brake cables if you are careful. The tank is now held in by two straps. It probably weighs about 20-30 pounds empty, but its big and unwieldy. It may require some manhandling.

dont forget to remove the 2 screws under the metal plate on the console. its under the small storage ashtray like section in front of the console

The fuel pump bracket seal and seal on the fuel tank inlet are more important (although the fuel tank inlet doesn't have to be removed). Definitely replace the fuel pump seal though...

Have you confirmed that the fuel pump is not working, first by shorting the B+/Fp test connection with ignition on, then directly at the fuel pump connector under the console. It makes a click, but does not run and whir like it normally should. If no whir, you need to replace it.

My tricks on this one were to lengthen some of the small dia hoses and use a transmission jack to hold the tank while installing. It is a tight fit and the tank is a lot longer than you will expect.

If you have a gas drain, that makes life easier. Mine didn't, so I just used a jack to slowly lower the tank, and also raise it back up into place. You don't have to disconnect many lines if you unbolt the loopy thing that goes up the firewall, it all comes out as one piece. The pain in the ass thing is the filler hose, it's old, it's hard, it's brittle, it doesn't want to move. Test your new pump while you have it out. Mine for some reason didn't want to go, and I had to drop the tank AGAIN, I was not happy.

[AustinTXMk1]

Great post Yellow Jacket!

I've got a fresh fuel gauge sending unit and want to install it as the installed one only reads about half full when it's completely full. However, I don't have fresh parts for the potential of having to replace parts that have over 300K miles on them.

Given this, is it possible to to replace the sending unit without dropping the tank completely? By completely, I mean can I tilt the tank by removing the front strap, and and loosen or remove the rear clamp enough to bring down the front of the tank enought to replace the sending unit?

Has anyone tried this before? I currently have approximately a gallon or less in the tank.

If anyone has done this, or can understand what I'm proposing, and care to respond before Sunday Morning CDT - I'd greatly appreciate the response and prior experience!

[muffinman]

Originally Posted by AustinTXMk1

Great post Yellow Jacket!

I've got a fresh fuel gauge sending unit and want to install it as the installed one only reads about half full when it's completely full. However, I don't have fresh parts for the potential of having to replace parts that have over 300K miles on them.

Given this, is it possible to to replace the sending unit without dropping the tank completely? By completely, I mean can I tilt the tank by removing the front strap, and and loosen or remove the rear clamp enough to bring down the front of the tank enought to replace the sending unit?

Has anyone tried this before? I currently have approximately a gallon or less in the tank.

If anyone has done this, or can understand what I'm proposing, and care to respond before Sunday Morning CDT - I'd greatly appreciate the response and prior experience!

you don't have to drop anything to replace the sending unit. just remove the center console , unplug the connector , remove the screws and pull it straight up and out (you might have to turn it as you lift). it's really easy.GL

[AustinTXMk1]

Muffinman,

I find this hard to believe as from what I seen when the center console is removed is mostly body shell and a some hole (25 to 30 mm) where a could of connectors are protruding. From this I don't see how to remove the sending unit?

About the only other way to possibly do this without removing the fuel tank is to remove the shifter assembly. I haven't done this and this may be the only other place where there might be enough room to remove the unit, but I don't think there is a through hole - can't see any light or anything like that from underneath?

Are you sure you're speaking of a Mk1? Mine's a June of 85 variety.

[muffinman]

Originally Posted by AustinTXMk1

Muffinman,

I find this hard to believe as from what I seen when the center console is removed is mostly body shell and a some hole (25 to 30 mm) where a could of connectors are protruding. From this I don't see how to remove the sending unit?

About the only other way to possibly do this without removing the fuel tank is to remove the shifter assembly. I haven't done this and this may be the only other place where there might be enough room to remove the unit, but I don't think there is a through hole - can't see any light or anything like that from underneath?

Are you sure you're speaking of a Mk1? Mine's a June of 85 variety.

YES!

directly in front of the radio is the fuel sending unit. all you have to remove is the center console and radio surround. once you have that off take the screws out that hold in the sending unit and lift out. 85-89 are all the same.

[muffinman]

remove the cover in the pic (3 screws where the wires go through)and the fuel sending unit is right there

[stu4u3]

I pulled my tank about 4 weeks ago to replace the fuel pump. My tank is rather rusty and the fuel sender was in bad shape. This will take you at least 1 full day (probably 2) to complete.

[muffinman]

Originally Posted by stu4u3

I pulled my tank about 4 weeks ago to replace the fuel pump. My tank is rather rusty and the fuel sender was in bad shape. This will take you at least 1 full day (probably 2) to complete.

he does NOT need to remove the tank to replace the fuel sending unit.

[senn]

OK so far i can see it looks like if all you want to do is change the sender you don't have to drop the tank.

Is there any way to remove the fuel pump using access only thru the hole where the sender was. I'm doubting it, but figure i'd ask anyway

NVM, just found this pic, looks like the pump access (if thats it at the rear of the tank) is gonna be completely hidden..Anyone know how far back it actually sits, and if it'd be possible to make an access hatch?



cred to woodsport for the pic, from their audi v8 conversion Mk1 page V8 conversions

[muffinman]

Originally Posted by senn

Anyone know how far back it actually sits, and if it'd be possible to make an access hatch?

even if you cut out the metal directly above it you still would not be able to pull it out because the fuel lines are metal and run all the way back to the end of the tank.

[woodfish81]

i just bought an 89 mr2 from a guy he had just changed the fuel pump and did a bad job he broke a fuel line off at the filter and put a rubber line with clamps it didnt hold now i cant find the line and also they hard wired the pump to the battery any guess on why i thougt maybe a bad fuse somewhere or a relay was bad and thats why they changed the pump if so were are the fuse for the pump and relay located anyone?

[mr2tim]

Having done 3-4 of these I'd suggest pulling the tank and flushing the rust out you will absolutely be amazed how much you will find in a 20 year old tank.
Cheating on maintenance is not wise.

Besides, without flushing you may be back in there to change the $15 in tank filter attached to the pump way way to soon. Clogged filters burn up pumps!!

As suggested you will want to use a floor jack to push the tank back up too.

Attach strings to the tank's wires to facilitate easy fishout thru the console "holes".

I color spray all the connectors to the tank to help with re-assembly hook-ups

Series 1 cars 85-86 do not have tank drains only the 87-89 series do, sorry.

Changing the fuel filter might be a good thing while your there on your back too.

Keep fire extinguishers and water hose handy!!

[not12listen]

i will be draining and dropping my fuel tank this upcoming weekend, so this thread is hugely helpful!

this thread also made me question whether my new Walbro 190LPH fuel pump came with a fuel strainer or not... thankfully, it does.

i'll do my best to catalog all of the hoses (ie. length, diameter, etc), to make it easier for someone else to replace their own later on, as i fully intend to replace all of the hoses that i can while i'm there.

[muffinman]

the only one that broke on me was the big filler hose. the rest were just a pita. GL

[not12listen]

i'm just going to replace all of the hoses as a matter of course. there is no reason not to, and it'll maybe cost $50 in hoses (over exaggerating prices on purpose), and it'll give me that much more time, before they'll need to be replaced again.

i also figure, the current hoses are 25 years old... all of the hoses are due for an overhaul.

[scottohno]

whats the stock fuel pump's GPH? is 190 GPH a big improvement? or is it stock?

[not12listen]

i do not know the LPH of the factory fuel pump, but it was made quite clear that using a 255lph pump would be too much and might cause problems... like destroying the fuel damper or perhaps the fuel pressure regulator.

[scottohno]

even on a supercharged mr2? if i blow the regulator i will get an aftermarket. im going to want more fuel to it anyways as i hear the GZE leans out under full boost at low rpm stock. but if i run higher fuel pressure i should be fine.