Team420

I usually dont replace anything till I need to.... Just sayin... if the tank is full of rust and gunk... dont just replace the tank, replace the tank/pump/sock/filter... and ya may even need to have your injectors cleaned at that point... worst case....

ETA... all that said... I prolly still wouldnt replace the tank... I'd just take the time to clean it out good, and maybe replace the pump/sock... Bit I'm also a cheap bastid

odonekanobe

What about a plugged cat? Runs fine after it's cleared out the obstruction but then another one eventually plugs it again. Happened to my '85.

Gamefreakgc

Was gonna comment on your fuel tank... if this were a fuel issue it would hesitate and possibly even shut off when you applied heavy throttle. It doesn't seem like this is your issue. These fuel pumps last a very, very long time. 285k on the original one for me.


It's worth checking the fuel filter though, mine was pretty bad on my rig.


I've checked every suggestion listed in this thread so far (timing, fuel filter, tank, cat, etc.) and I still have the same issue you have. They are all worth checking at least, since there might be other side effects, but I highly doubt any will fix the issue completely. Like I said, I know it's electrical since it'll reset a CEL light. Bad timing or poor fuel pressure won't do that.

FuelforWar

Well I got the stupid thing home. It did not want to behave one bit. The problem has gotten severly worse in the last few day. It choked 3 times on the way home. Each time I had to pull off the road and wait it out a few mins. My motor never died it just wouldnt rev up. Sometimes worse than others. Anyhow about to go out and pull the tank. Wish me luck.

FuelforWar

Well this is exactly what is happening thou.. im driving along, then it hesitates, sputters, then wont rev up til I tap the gas over and over til what ever the issue is clears out or corrects. Also I never mentioned this but my truck doesnt have a cat. Its just staight piped to the muffler. Alao I replaced the fuel filter on monday night so I know thats not the issue unless its already plugged again...

Team420

Yeah... "sounds" like jumk plugging the fuel pump.... i you can pull over, and it "settles" down,..... its likely a variable, like junk in your tank.....

Start there,,,, if its not "floaties", at least you can rule it out, and it costs nothing but time....

Either that... or you gots a blown hg.... lots of crazy stuff can happen with a blown hg..... might wanna start with a compression test.....

Thats where I usually start when it comes to diagnostics....

FuelforWar

I hope is not the head gasket, I just changed it about 30k ago and it was a pain.

FuelforWar

Well I didnt get much of a start on it. I had to go pick up my buddies car til I can figure this mess out. Weird driving a car again. Kinda cool thou driving my favorite car from gran turismo (3000gt). So from what I can see its just the 6 bolts that hold the tank up, the fill hose and overflow, the wire clip, one hard line, and two small hoses right? Do I need to disconnect the hardline before lowering the tank? Looks like a pain to get to, even with the 3 inch body lift.

odonekanobe

Straight pipe takes away my cat theory. I'm wondering if a muffler could get messed up enough to do the same thing as a plugged cat? Probably not....

FuelforWar

The muffler and pipe from the o2 sensor back was replaced about 2 years ago. For how loud it is I highly doubt theres any restrictions in the exhaust system. I still havent ruled out the egr valve yet thou....

bbrideau

just waiting for days off then i will be tearing into the wife's 4runner and hopefully be able to figure some stuff out to help you as well. My method will be, compression test right off the bat then if that clears I'm dropping fuel tank then working forward form there. see how it goes.

Edit: Her truck isn't throwing any codes so I might be lucky and not have an electrical issue... who knows. Usually bad things come in threes tho and her truck will be third strike. Engine grenaded on my work truck, The tracker i used as a daily commuter shorted out the ecm and fried the wiring front to back and now the wifes truck.... hope its not as bad as the last 2 haha

Gamefreakgc

My bad, I think I might have missed a few posts in there. You're right then, if you actually are having those symptoms! I think though that the "stutter" might still be lingering after the fuel delivery/loss of power issue is resolved but if not, let us know what you did.

FuelforWar

Ok guys, well I just finished pulling the tank and pump. The inside was very clean. The only place I saw any rust was in the the area the filter sits. I took a long wooden cuetip and brushed the spots to see if any od the rust was loose. Nothing came off. Other than this there was a half dozen small little things in the tank (most of which probably fell In when I was pulling the tank). Now as for the pump sock, it was all clean but one little area the size of a nickle which was full of dirt, metal, and what looked like hair. So is there a way to see if the pump has something in it or to clean it? I took a couple pics ill upload when Im finished working for the night.

FuelforWar

Looking forward to see what you find. If my pump checks out, this will rule out all but the injectors in my fuel system.

CarSick?

Food for thought:
Bad fuel injector connection(s) or Knock Sensor?
FPR Maybe?
Fuel Damper (on the back of the fuel rail)
Wiring to the fuel pump?
Could the igniter inside the distributer have anything to do with it?
MAF?

Good luck

FuelforWar

My computers wont let me upload the pics but I made a discovery. I pulled the pump from the sending unit and the connecter for the pump was caked in crud. Im curious if the circuit keep shorting out or was passing a weak signal. Thoughts?

FuelforWar

So can I test the pump with the ohm meter? I dont see any damage to the blades so ill leave the pump if its fine. If I can does anyone know the numbers I should be getting?

Gamefreakgc

Any caked connector or one covered in rust it a potential issue. It may not necessarily cut out, but will increase the resistant (ohms) of the current. Since the ECU will read voltages based off resistance (returning voltage), this could give a false reading or under-power the pump. You want to see glossy metal (I think these are brass or copper connectors, so they won't get "sparkly"), anything less needs to be cleaned or in a worse case scenario, replaced.

I'm 50-50 on dielectric grease (which might be the crusty stuff you saw). The stuff I've been using has a tendency to dry up and harden, leaving a crust. Some say it's good and helps the connection but for a fuel pump, which you probably never want to drop the tank to get to it ever again, you might want to omit it. FSM doesn't ever mention it, so up to you.

FuelforWar

I see, so just to clarify, the connector I found caked is the one that plugs right to the fuel pump thats inside the tank. Not the one that plugs to the assembly on top of the tank. I was pondering if it was di electric grease but its only around one of the terminals and its far from the color of dielectric grease. It is a bronzy brown color and full of metal shavings. I will clean this thoroughly. Im not very familiar with how the pump operates. Does the pump increase in speed as the rpms raise? My motor doesnt die, it just wont rev up. If the pumps not getting enough signal to increase the pressure this would cause this issue right?

FuelforWar

Well sad news everyone. In the process of reinstalling my tank i damaged the hardline that goes into ghe tank. Looks like ill have to replace the fuel sending assembly before I can test my hypothesis. Once again more bad luck.......