esievel

I have a 1983 toyota 4wd.pu 4 cyl. gas. Lately on occasion my vehicle has been acting like it's running out of gas even with full tank of gas. Pretty much only at speeds above 55. I have done plugs wires, cap, rotor, fuel filter, air filter, releasing gas cap, I believe it may be relevant to the catalytic converter but what is throwing me off is it always seems worse in the hottest part of the day. Makes me think it's some sort of sensor.
Also, I don't know if it is related but I also have very little power climbing big hills. I sometimes can't get over 55.

Bingle

Hard to say but start by checking the fuel pump. Could also be a carb problem, filter sock in fuel tank getting clogged, fuel filter, old fuel lines colapsing or at least restricting fuel flow, and that's if it's a fuel delivery issue like you suspect. Check timing and make sure your vac advance is functioning properly.

Could be lots of things. Start by eliminating the easy/cheap stuff first. Good luck.

kawazx636

iTrader: (3)

Stock carb or Weber??

What size tires? If you have 33" or larger tires with stock gears, your engine likely won't pull well up hill.

Is this a new thing or did it start after you added or changed something?

Bingle is right - start with the free/easy things first. Sounds like a similar fuel filter problem that I had.
1 - Check to make sure that you don't have 2 fuel filters. Some trucks came with two - one on the passenger side fender wall and the other on the frame rail below the filler door.
2 - There is also a fuel sock like Bingle said in the gas tank - those things get clogged up pretty well too. Drain the fuel tank to see if you have a bunch of rust or contaminants in your fuel. I would completely drop the tank and clean it out - it really isn't that difficult to do. My truck was in rather good shape and I still had a decent amount rust scale building up in my fuel tank and fuel lines.
3 - Check/replace your rubber fuel hoses. If they look bad from the outside then they are likely bad on the inside. The rubber hose is rather cheap from your local parts store.

Ideally, you want to clear up ANY AND ALL fuel deliver problems first before you move forward with the fuel pump and carb. It may solve your problem, but if it doesn't at least you know if it isn't causing your problem when you start troubleshooting everything else. I've seen people buy and screw up perfectly good carbs because they started troubleshooting at the carb without clearing up any fuel delivery issues first - They were dumping nasty fuel and contaminants into a brand new carb and not solving any problems.

esievel

I believe I've done all the free and easy stuff. The problem came out of the blue. I am down to dropping the tank and checking the sock, the egr or the catalytic converter. Everything is stock on the vehicle. My issue is that it is irregular. The vehicle actually started driving reasonably well and then again today it acted up as bad or worse than it had previously. btwThanks for the input.

84YotaBuck

Any update? I've got a similar issue, just replaced fuel pump and filter but the problem is still there.

gillesdetrail

iTrader: (1)

Make sure the pump love on the cam is not worn out!

esievel

I can't say that I have it solved for sure but I have seen improvement. After my last post my trucks performance has gone up and down. I did the plugs, cap, wires, rotor , fuel pump, air filter, etc. saw improvement. Then one day the truck was acting worse than ever, pulled over and disconnected the catalytic converter, no improvement. I reinstalled the catalytic converter and then disconnected the compression fitting going to the EGR, I could hear a release of pressure. It ran better, much better and had for the last 2 - 3 weeks. In recent days , I let the fuel tank get a bit low and after filling I experienced the "bog" when letting up on the accelerator pedal up on the freeway. So where I'm at is that I believe it's dominant cause is the egr system as well as fuel issues , e.g. dirt , ethanol, etc

Good luck, If you figure it out for sure , Please let me know.

slacker

iTrader: (1)

there is also a "sock" or filter IN the tank .. very common to clog , and should be replaced


.

esievel

Thank you, I am aware but have not been able to set aside the time to drop the tank. One of the difficulties I had in identifying the cause of my problems is the irregularity. My problem also seemed to happen at the hottest part of the day on the hottest days. I'm in NM.

83Toyota88

iTrader: (1)

My 2 cents:

If you have a stock carb try this. Get the truck warmed up and under the hood manually increase the accelerator linkage. Try and hold the motor around 3K-3500rpm and watch the fuel level in the sight glass of the window while you increase the rpms and hold it steady. If the fuel level stays pretty constant around half way in the sight glass, it shouldn't be a fuel delivery problem and is most likely a carb issue or a motor in need of a de-smog.

You won't be able to do this with a weber unless you have a pressure gauge inline with the fuel pump to watch pressure as the rpms go up.

But I would drop that tank as soon as you can. Its not that bad to do, I would say 2 hours tops. I believe there are 3 bolts on each side plus the removal of the filler neck. You may have a lot sediment clogging up the sock restricting flow at high rpms.

esievel

That is very good to know although even though I believe the carb is stock. I never noticed the "sight glass", should it be obvious?

83Toyota88

iTrader: (1)

Front side of the carb is a small glass window with two small screws on each side of it.