V6 Surging under load

[jogal]

Under a heavy load or when towing a heavy trailer i have found that i when i power on say on the feeway i find the power isnt smooth more of a surging feeling! has anyone with a V6 found this with their vehicle ? and if so what is it?

[Ggn25]

i've experienced 2 vehicles with the same issue. there can be many different reasons but the eventual cause of the 2 i talk about were fuel pump issues. both had long range tanks and maybe the pumps failed prematurely due to a lack of fuel/lubrication of the type of tank without enough fuel in the swirl pot.

but make sure all the basics are done and checked first. Fuel filter, spark plugs , leads , coils and air flow sensor clean.

cheers Tim

[sbeer7]

Definately sounds like a fuel problem. Not getting enough when needed. I would be checking fuel filter, prob blocked up. I had the same problem with a work ute, (was a triton though ) And as soon as the fuel got down past a quarter left, it would surge real bad, turns out there was crap in the fuel tank, and when low, would block the fuel filter. Ended up getting a new fuel tank.

[LowVp]

or can be a coil on its way out

[jogal]

I do have a long range tank! i'll look into this..........
It only had it's 100k service about 6 weeks ago surely they checked most things.
In saying that i experienced the worst service i've ever had i was going to post a separate thread about this i just never got around in doing so! it was unbelievably bad .
If in Perth never go to the dealer near the( CITY) for your services...................

[KTM525EXC]

i would start with the oxygen sensor, from there id check if all the plugs are connected properly. when were the spark plugs changed last?

[jogal]

I'm pretty sure they would of been changed at the last service

[KTM525EXC]

do you have the last service receipt? if not, have a look for yourself, take one out and see how clean the tip is.

[jogal]

Where would I fins the 02 sensor?

[KTM525EXC]

on the inlet pipe just after the airbox ill find the thread for you

[KTM525EXC]

here you go viewtopic.php?f=13&t=6272&hilit=02+senser

[Elrico]

Personally, i changed my spark plugs to a cooler plug, PFR6B to PFR7B in my old subaru and when under load (24 psi) it would miss fire on the 6B's and go smooth to redline on 7B's. Now, i had a service and told the mechanic what the deal was. They didnt listen and just put a new set of 6B's back in and alas the problem was back. Wondering if this could be a simular problem.

[Give-us-a-brake]

I've been having the same problem for ages with my 4.0l.
Finally fixed it last night...
After weeks of playing around and a cost $1500 of bits and pieces (inc. 02 sensors and pulling off the manifold and removing and cleaning injectors) it turned out to be a weak fuel pump.
There was some water in the tank so possibly this caused it to wear out prematurely.
Pumps are about $500 from Toyota, but I got a Denso pump in Perth for about $150.

[jakedehaas]

Hi,

Sorry to bring up an old thread, but I'm having the same problem with my hilux also. Slight surging when under load at around 2-3k RPM and quarter to half throttle. I also have a long range tank fitted.

Ive been on the hunt for aftermarket fuel pumps (Denso) but no where in my area seems to have them. Would you be able to tell me where you got the Denso pump in Perth. I had a look on the Denso website and they dont have a listing for the Hilux, only the Tacoma.

Its PN 950-0210 for $154.

Cheers for any help you guys can give.

Jake

[jakedehaas]

Right,

just bringing this up again to say my problem is at last solved. A big thankyou to Jap for pointing to the fuel pump to fix my issues and for the help he gave, top bloke.

For those of you that are experiencing any sort of surging at about 30-50% throttle between 2-3k RPM, you have a V6 and a long range fuel tank, the fuel pump is most likely your problem.

The replacement fuel pump can be found here,

http://www.urdusa.com/Fuel-Upgrades-Fue ... _info.html

Its a Walbro 255 LPH pump. There is some slight modification to be made to the fuel pump bucket to fit the pump in, but its really quite simple.

The hardest bit for me was removing the long range fuel tank. I needed to remove the rear drive shaft, so I just left the tank in place and dropped the front of it down. I dont recommend doing this though as it would have been less hassle taking the driveshaft off.

In all, my hilux drives 100% better, the power is smoother everywhere, the engine note is nicer at full throttle and just in all the driveability is so much better. If you've got this problem, this is the fuel pump you need.