Lately my engine has been losing power and totally wanting to die out on acceleration. The engine will always idle normally but usually 2-3 minutes after driving from startup it would start bucking popping and wanting to totally stall. I had the idle set to 1000 rpm mainly because of the weather change I was trying for around 800. Figured it was no biggy and would change it later, I just needed to fix the problem at hand. I changed the distributer cap, plugs, wires, checked the tps, cleaned all the electrical plugs, battery terminals, eliminated cel, and the problem still existed. I was going to change the fuel filter but noticed it was from 2009 and the truck has barely been driven since I put it on. The last thing I suspected was injectors, egr valve, or fuel pump. Today I was driving and the truck started wanting to stall on acceleration to the point of no return sometimes it would come and go but it just didn't want to go over 10mph without cutting out and popping so I pulled over and turned down the idle screw on the throttle body way down just to see what happened. I got back in to pull off, the truck was Idling at like 200 on pull off, but I immediatly noticed a difference. No more wanting to stall so far. I came to a stop and noticed then that I was idling 600 steady. Drove the rest of the way home with no problems.
I still feel that I need a proper adjustment here and I'm not quite sure what I need to do. If I go to low I will stall if I go to high I'll be flooding again. I noticed the dashpot and another thing beside the tps that can be adjusted for throttle. I'm not sure exactly how to adjust these because the manual is somewhat unclear to me. Also are the plungers supposed to opperate smoothly with the throttle on these two mechanisms? I noticed the plungers just kicking in once and a while on acceleration and it is quite hesitant to do so.

 

Ok so it started doing it again as soon as I got back in to drive to work. The truck has plenty of power but its seems as if the fuel supply is just getting cut on and off. I am starting to think the pump is going bad. This morning I was driving home and it started so I kept the peddle in a steady position while my truck choked its way down the road and then it suddenly kicked in and started to drive normal. At one time under steady acceleration it totally died out and then kicked back on. It does it on and off constantly. Sound like a fuel pump to anyone else?

 

I was having similar issues. When my fuel pump was pulled there was no screen on the intake of the pump and there was rust in my tank. It caused intermittent lack of power, stalling, bucking, ect...

I have a 4runner with the access hatch for the fuel pump, so wasn't a big deal. Not sure about pulling the pump on a pickup whether it requires dropping the tank or removing the bed.

 

just realized that the vacuums to the bvsv were wrong. Ill drive it around and see if its fixed.

 

Mine has also done this . In my case it was the main relay in the fuel panel ,cutting on and off.

 

I mean "fuse" panel.

 

Hey im having similar issues ive checked everything but fuel pressure reg and havent dropped the tank mine is bogging under steady pressure but wants to drive if i floor it still weak tho ive replaced tps checked maf sensor replaced fuel filter all plugs wires rotor cap it seems to do it worse when less fuel in tank and when i hold 2k rpms steady it starts pulsating ive noticed today? Any suggestions ive wasted 50 bucks on a useless diagnose already

 

What did it say? Why is it useless?

Can I assume that the timing was checked? (A timing light is only a fraction of what you've paid so far in parts alone . http://www.harborfreight.com/xenon-t...ight-3343.html)

 

first what engine are we talking about? 4banger, or v6? carb or EFI?

check your maf, its function is critical because it turns on the fuel pump. if its clogged, lost a fuse, or the tube to the throttle body has a leak it won't function properly and it won't want to run correctly. if the sensor is fine, clean, filter clean/new, check where the air comes in, i got that covered in mud once and my truck couldn't breath.

check all connections to the throttle body for leaks, even the sensors that just plug in, if they are leaking air in or out it could effect it.

also check out distributor timing, that your wires are correct

check that your valve adjustments are correct, if they're not opening you're not going to be running good.

if you have an automatic transmission check the fluid, flush the fluid if you have to, it's might not sound related but if you have a clogged transmission it'll make your engine "stumble" had that problem in my dads truck.

also check if the exhaust (at the tail) is sucking in air, if its sucking in instead of blowing out you have a leaky exhaust valve and it'll choke your truck, I had that problem on mine.

everything is related to a good running vehicle, if your computer is wet, it wont run good, if your wires are corroded it wont run right, if timing is off, if the vacuum lines are off, if the air/fuel is off, theres so many things that can effect a vehicle (which is why as a mechanic I actually keep a job) all you can do really is eliminate possibilities and you'll come to the answer. my buddy had a wiring problem that when he'd turn his headlights on his truck would die, its a system that needs to work together to work properly.

 

Hey i realize im posting this almost 3 months after the most recent post, but my dads 4runner was having a similar problem and it turned out to be the fuel pressure damper

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