Fuel pickup clogging?

[daeron]

First off, my simple question: how hard is it to access a fuel line that can be blown into with hig pressure air in order to blow out the fuel tank pickup? Do i just disconnect the line from the pump to the tank and blow? (obviously taking precautions not to get a face full of fuel.. :-p)

 

Okay, if you want you can skip the explanation of my background problem..

 

My car still doesn't run quite right. I haven't gotten to do much diagnosis of it, but it has an odd issue that seems almost like fuel starvation, or a fouled MAF, or bad TPS. I haven't tested the TPS yet, the MAF has been cleaned, swapped with another, and then replaced with original due to no difference. Last time I checked codes my most significant issue was an O2 sensor code in d-check only. (i think a VSS and a neutral position switch, too, something like that anyhow)

 

So anyway, once in a while it starts acting like it has no fuel supply at low RPM, throttle response can seem poor; Really, the intermittent "issue" I am tracing is very odd in its manifestation.. but I am going to check fuel pressure. One thing that is beginning to suggest itself to me is either bad fuel pump, or more likely a clogged pickup in the fuel tank. This makes sense because I know how to use every last useable ounce of fuel in my tank, and I do so ALOT. TOO often, honestly.. I also put a little seafoam in the tank not *too* long ago, and I realized the other day that my "issue" more or less began then.

 

Now, my "issue" was severely compounded by my blown headgasket; the car barely ran because the compression finally reached a critical point of difference (185 vs 150) between the two sides. So my car runs MUCH better since doing the HGs.. but sometimes I hit the gas and it just seems to miss half its fire.. it just goes chug-chug-chug.... The timing is set dead on, per FSM procedure. I am utterly confident in that, the symptoms are exactly as they were before I did the HG job. Just less severe, and less acute.

 

Anyhow, I want to maybe blast it out and see if it makes any difference. Before I bother doing so, I will get a fuel pressure gauge spliced into it somehow.. I may even be able to find a way to install one into the car (semi?) permanently to make sure I can watch it while the running issue occurs.

 

Anyone else have any thoughts?

[heartless]

um, just a thought, but have you thought about changing the fuel filter???

 

the other thought i have is blowing the "crud" back into the tank from the fuel pickup is NOT going to solve the problem, as the crud will eventually work its way back to the pickup (if this is indeed the issue).

not sure what the inside of a subie fuel tank looks like, but if you have crud floating around in there, it may be time to replace the tank - or pull it and attempt to flush it out.

[mikeshoup]

How old are the plugs, wires, cap and rotor?

 

My silver 88 wagon had a miss on it, much like you are describing. Replaced the above, and it worked wonders.

[[HTi]Dain]

After doing headgaskets, they often have to be retourqed after, about 500mi. of driving. Unless they otherwise specify with the gasket. Felpro permatourq gaskets I think are the best, and strongest way to go. If you do not retourqe, non-permatourqe gaskets, they will blow again. especially on an ea82. just a thought

[daeron]

maybe 10-15K on the cap, wires, and rotor, more like 30K on the plugs, I forget when I changed the fuel filter but somewhere in the last 20K miles..

 

And I did use permatorque headgaskets.

 

I know about the crud in the fuel tank, I have been trying to find a way around that.... However, if I blow it out, and have a decent amount of fuel in there, it SHOULD at least improve for a little while, indicating im on the right track.

[idosubaru]

i'm betting it is not fuel related.

 

how's the CTS? check your cap and rotor, i've seen new ones off the shelf turn to crap fairly quickly (in a matter of days), it's worth a quick peak. do you have an extra distributor to swap in place? i've seen a couple of these fail and every single time it was while the engine was down and apart for head gasket work...my speculation is that corrossion messes with the CAS if you have that style disty. every time the disty tested fine and no check engine light too...but car wouldn't start at all or only for a couple seconds in those cases.

 

does it do this all the time? maybe it's exhaust related, catalytic converter? maybe when the headgaskets blew the first time the coolant and overheating toasted your converter? just a WAG.

[daeron]

the symptoms I am having are still (some of) the same that I was experiencing before the HG job, so i cannot see that anything went south in doing that. The run condition improved IMMENSELY after replacing the HGs..

 

It doesnt help that I have had between 5 and 1 1/2 gallons of fuel in the tank virtually for six months... I mean, i havent had more than a quarter tank since september, and I have been running each tank down to the last drop. I mean the last drop, too.. I know exactly how far I can go before I run out of fuel, and there is still about a gallon or so left in the tank at that point.

 

The CTS, I checked; but it tested right (function-wise) and my car isn't a turbo; I was told the connection is predominantly a turbo car issue... Even so, the connections look beautiful, like brand new... NO complaints there, and even still I tried spraying, cleaning, wire jiggling, the whole nine yards to no effect.

 

I've replaced the TPS with a junkyard unit already; so I HAVE experienced a bad TPS problem, and it isn't the same as it had been before. Also, when I fixed my TPS problem, it got alot better... but I had hoped it would improve more than it did.

 

I inspected the cap and rotor, and actually gave them a light resurfacing, while I was doing the HGs. Another DISTINCT possibility is a coil issue, since I had been bubbling out of my reservoir for eight months that ENTIRE quadrant of my engine bay is covered in a rusty haze, and I *certainly* need to make sure none of the corrosion is having a negative effect on my ignition system.

 

It starts right up. It usually runs fine, but it often has this bogging issue... it seems more prevalent when there is less fuel in the tank.

 

I am normally really good at symptom recognition and summary.. I mean, even if *I* can't figure out the cause of problem, I can usually generate a good report of what my issue is to get help; this one is REALLY off the wall, and I can't pin it down enough to REALLY communicate what I am experiencing to you guys..

 

I definitely need to check:

 

Codes (haven't done since the HGs..)

TPS

Fuel Pressure, not just adequacy but consistent adequacy

Coil connections

Cap/rotor type stuff

Fuel Filter

and Actually electrically test the MAF, but changing MAFs didnt make a bit of difference so I doubt that

 

I say I know when I am going to run out of gas.. this is because the car tells me when I go around a turn to fast on empty.. anyone experience that? you hit the accelerator, and it just the-THUG-thug, the-THUG-thug, spit spit THUGTHUGTHUG VROOM.. except getting the Vroom to come in isn't easy. throttle position seems to make a difference, but its relative throttle position, not absolute throttle position.. I mean, flooring it usually makes it over the hump the best and the quickest.. but I say "flooring" and I mean pushing the gas down far enough that it would be at full acceleration... not necessarily full WOT, but that point where normally, if you hit the gas any further you really arent making it accelerate any quicker...

 

Like I said, the data I am getting on this issue is really fuzzy, and I can't interpret it well wnough to even communicate it to you guys. I have been half-assedly trying for a couple months, now, but I just can't do it.. the video I took wasn't that helpful, but maybe I will try that again...

 

Thanks for doing all this reading, everyone.. I am REALLY stressed out right now so my communication skills aren't up to snuff, and I am long winded on the best days... sorry if this is confusing.

[Roger87ea82t]

First off, my simple question: how hard is it to access a fuel line that can be blown into with hig pressure air in order to blow out the fuel tank pickup? Do i just disconnect the line from the pump to the tank and blow? (obviously taking precautions not to get a face full of fuel.. :-p)

 

Okay, if you want you can skip the explanation of my background problem..

 

My car still doesn't run quite right. I haven't gotten to do much diagnosis of it, but it has an odd issue that seems almost like fuel starvation, or a fouled MAF, or bad TPS. I haven't tested the TPS yet, the MAF has been cleaned, swapped with another, and then replaced with original due to no difference. Last time I checked codes my most significant issue was an O2 sensor code in d-check only. (i think a VSS and a neutral position switch, too, something like that anyhow)

 

So anyway, once in a while it starts acting like it has no fuel supply at low RPM, throttle response can seem poor; Really, the intermittent "issue" I am tracing is very odd in its manifestation.. but I am going to check fuel pressure. One thing that is beginning to suggest itself to me is either bad fuel pump, or more likely a clogged pickup in the fuel tank. This makes sense because I know how to use every last useable ounce of fuel in my tank, and I do so ALOT. TOO often, honestly.. I also put a little seafoam in the tank not *too* long ago, and I realized the other day that my "issue" more or less began then.

 

Now, my "issue" was severely compounded by my blown headgasket; the car barely ran because the compression finally reached a critical point of difference (185 vs 150) between the two sides. So my car runs MUCH better since doing the HGs.. but sometimes I hit the gas and it just seems to miss half its fire.. it just goes chug-chug-chug.... The timing is set dead on, per FSM procedure. I am utterly confident in that, the symptoms are exactly as they were before I did the HG job. Just less severe, and less acute.

 

Anyhow, I want to maybe blast it out and see if it makes any difference. Before I bother doing so, I will get a fuel pressure gauge spliced into it somehow.. I may even be able to find a way to install one into the car (semi?) permanently to make sure I can watch it while the running issue occurs.

 

Anyone else have any thoughts?

 

If you do blow out your gas line be sure and remove the gas cap first so you won't build up pressure in the tank.

 

When you pull off your fuel pump check the inlet pipe, inside is a plastic screen that will pop out with a small screwdriver or an awl. I have had fuel delivery problems before and after testing and changing eveything I could think of, including the fuel tank, I finally found the inlet screen in the pump was plugged. After cleaning it all my problems disapeared........Roger

[daeron]

If you do blow out your gas line be sure and remove the gas cap first so you won't build up pressure in the tank.

 

When you pull off your fuel pump check the inlet pipe, inside is a plastic screen that will pop out with a small screwdriver or an awl. I have had fuel delivery problems before and after testing and changing eveything I could think of, including the fuel tank, I finally found the inlet screen in the pump was plugged. After cleaning it all my problems disapeared........Roger

 

Thank you!!! THAT was exactly what I was looking for. I thought I had read something about that, and this was the simplest way for me to find out.

[daeron]

When you pull off your fuel pump check the inlet pipe, inside is a plastic screen that will pop out with a small screwdriver or an awl. I have had fuel delivery problems before and after testing and changing eveything I could think of, including the fuel tank, I finally found the inlet screen in the pump was plugged. After cleaning it all my problems disapeared........Roger

 

This is a very simple little task that I can accomplish in my driveway, at home, with a limited selection of tools, right? Something that shouldn't take an hour from the time the jack comes out to washing my hands? I don't enjoy getting into major jobs in my driveway that I am not already well acquainted with, because my house is not my workshop; I have little more than the tools I keep in the car at all times unless I am up at "the shop." (My family rents and keeps a common garage now that my brothers and I are all grown) So I just wanted to make sure this was as simple as I anticipated before I jumped in. (unless I have some sort of major rust/plumbing repair that is unforeseeable, knock on wood...)

[Roger87ea82t]

This is a very simple little task that I can accomplish in my driveway, at home, with a limited selection of tools, right? Something that shouldn't take an hour from the time the jack comes out to washing my hands? I don't enjoy getting into major jobs in my driveway that I am not already well acquainted with, because my house is not my workshop; I have little more than the tools I keep in the car at all times unless I am up at "the shop." (My family rents and keeps a common garage now that my brothers and I are all grown) So I just wanted to make sure this was as simple as I anticipated before I jumped in. (unless I have some sort of major rust/plumbing repair that is unforeseeable, knock on wood...)

 

 

Yes, it is pretty easy and should take less than an hour. Get a pan like you are going to drain the oil out of your engine and put it under your fuel pump. When you disconnect the fuel lines you will have about a quart of fuel come out and you will want to catch it so you don't make a big mess. After you get the pump off, pry the screen out of the inlet pipe, it is plastic and I beleive has a split on one side. after you get it out look at it, if it's not plugged you should be able to see through it. If not blow it out with air or wash it in solvent, pop it back in and after you install it, drive down the road whistleing. ...........Roger