ok so my 86 xt mpfi non turbo is starting to be a real pain in the a$$. it likes to cut out the fuel at random times, but lately it wont make it past 1500 rpms after about 15min worth of driving, so i figured id completely drain the tank and start with completely fresh gas (keep in mind it has been sitting for a while and has a brand new fuel pump and filter) so to drain it i did it the lazy way and hot wired the pump and pulled the line off the motor side of the filter (so i can throw the gas in my honda cause it will run off anything) and as it was pumping about 5-10 min in it starts to pulse and a lot of bubbles came through the line( and there was still plenty of gas in the tank) it seems to me that there is a clog or some sort of restriction.

 

 

so my question is: is there a screen in the tank that can be replaced? and if i drop it is there a larger door (other than the sending unit) that i can get into? the tank is quite gummed up and i am sure this is the problem. seeing how i am broke i need to clean it not buy a new one. and the junk yards around here punch holes in the tanks to drain them so that won't work. ah... why must i have a subaru so badly? lol

Edited March 3, 200917 yr by rpholz

Pull the pump and check the suction side. I think the screen is on the pump. You might use a couple small bursts of compressed air through the line and blast the clog out or back into the tank (if its on the tank side).

is it sucking air through a leak in the line?

Check your tank vent lines for blockage !

 

The excessive pressure build up can cause this kind of symptom,

especially the fuel cutting "after 15 min. of driving" sorta theng.

Check your tank vent lines for blockage !

 

The excessive pressure build up can cause this kind of symptom,

especially the fuel cutting "after 15 min. of driving" sorta theng.

 

awesome, bet that's it - good one

Loosen the gas cap, and try pumping fuel again. If the flow stays steady, you definetly have tank venting issues.

well that is the thing the sending unit was out. so i know it had a vent. idk once i drop the tank i am going to thoroughly inspect every line to and from the tank.

May have a crack in one of the metal line sections,pressurise and listen for leaks,don't need a lot of pressure.

Could be worse once had a customer who had been to 5 shops,only played up on one particular hill no one could find it,turned out to be a leaf and when enough suction,occured it sucked the leaf over the intake for the pump real pain to find that one.

lol yea a leaf would definatly be a hard culprite to find. yea its just been sitting for so long that when you look in the tank you cant see any shiny metal, but i am way to broke to buy a new tank. i do hear a faint sound that sounds like a vacuum leak but then again i am not really all that sure how quite the little cover over the mpfi engines operate.

 

 

anyway the tank will be dropped tonight and ill post whatever i find to see if this is the problem(i just want it running right!)

I had this exact issue with my 86 XT with the fuel cutting out etc, the fuel pump seized due to rust.I solved it by replacing the gas tank on Sunday. Drove 200 miles yesterday and the previous problems are all gone. I had no trouble with bolts, the hose clamps were a PITA though. The tank was $200 shipped from rockauto.

 

I had quotes from radiator shops for $80-120 to clean and seal the tank. But there are only 2 moderate size access holes for them to clean it out...

 

After I pulled the tank (after draining it with the fuel pump) I turned it on it's side and drained the rustiest gas ever from the tank.

 

Again, my car was sitting for years as well as a project car with little gas in the tank.

 

You say there wasn't shiny metal in the tank when you looked... that was my problem and is most likely yours as well. You can call around to radiator shops and see what they do to fuel tanks, I had a quote of $80 to clean & seal the tank, but there's always the possibility of their work failing down the line... I bit the bullet and ordered a new tank.

 

Dropping the tank isn't awful. Spray all bolts and clamps with pb blaster beforehand, I had no trouble with bolts and my XT is from the midwest. There are 6 12mm bolts that hold the tank on, use a 10mm 1/4 socket ratchet to remove the gas filler hose, use a good philips head screwdriver on the hose clamps, use dull vice grips to break hoses free from fittings. If your xt is 4wd you'll need to drop the rear diff to get the tank out. To do this, loosen the two 17mm nuts on either side from the "moustache bar" and the diff will drop so you can get the tank out. Have new hose clamps handy because I wasted too much time re-using the old ones.

 

Feel free to ask questions while the job is still on my mind, it took me 5 hours from taking the old tank out & putting the new one in, most of the time was struggling with hose clamps.

Feel free to ask questions while the job is still on my mind, it took me 5 hours from taking the old tank out & putting the new one in, most of the time was struggling with hose clamps.

 

hey i apretiate the detailed instructions, yea just me if i had the 200 buck id definatly prefer to buy a tank but i will be cleaning it by myself with lots of different chemicals till i find one that works lol but hey ill hit you up if i have any further questions. thanks - ryan

*UPDATE*

 

so i thouroghly went through the tank and cleaned it to the best of my ability (lets just say it included compressed air, muratic acid, water and rocks... yes rocks:grin:) the amount of straight crap that came out of there was simply rediculous 3 out of the 4 smaller holes were completely clogged. i am going to let the tank sit for a day to dry, and tomorrow fish the rest of the rocks out of it and see if it worked. and if so i have a method of cleaning a ruined tank for less than 15 bucks. cross your fingers!

*UPDATE*

 

so i thouroghly went through the tank and cleaned it to the best of my ability (lets just say it included compressed air, muratic acid, water and rocks... yes rocks:grin:) the amount of straight crap that came out of there was simply rediculous 3 out of the 4 smaller holes were completely clogged. i am going to let the tank sit for a day to dry, and tomorrow fish the rest of the rocks out of it and see if it worked. and if so i have a method of cleaning a ruined tank for less than 15 bucks. cross your fingers!

 

I think that's an old hot rodder trick Hopefully it worked. I don't know if they make clear fuel filters for gas cars, but I would put one in the line between the tank and fuel pump inlet if possible, to see if junk is still getting out of the tank.

I think that's an old hot rodder trick Hopefully it worked. I don't know if they make clear fuel filters for gas cars, but I would put one in the line between the tank and fuel pump inlet if possible, to see if junk is still getting out of the tank.

 

actualy your spot on as to what i was going to do i was going to extend the line and through in a clear one if i can and zip-tie it to the side of the fuel pump bracket so i can inspect it perioticly(sp?)