Hi,
XH 4.0L Auto ute seems to surge going up hills?
Changed fuel filter, plugs, leads, air filter to no avail.
On the open road its fine, went to Auto Masters and they plugged in.
Told me everything was O.K???

Any ideas?
Also looking at changing out cam, any suggestions?
Ute has -
2 1/2" exhaust with extractors
K&N Filter
Gold Powerchip
3" air hose all way from box to manifold.

What are the torque specs for rocker gear and cam gear?

Hope you can all help?
Thanks.

I've got the same problem in my EL...

Have you had a look at the coil? They are prone to cracking under the mounting brackets, that hold it to the block.

My EF surges sometimes too. At the moment I'm suspecting detonation as the cause and am going to put some cooler heat range spark plugs in on the weekend. I'll let you know if it makes any difference.

My car has had a fair bit shaved off the head and airbox and exhaust mods. The surging and detonation got worse after I modified the airbox had a set of extractors put on a few weeks ago, I assume from the mixture leaning out.

You could also have deposits on your pistons and/or valves.

I put some of the JMM Autolite spark plugs in on the weekend and gapped them at .9mm. Surging and pinging has gone and it's made a big difference to the power, presumably because it was pinging most of the time (even when I couldn't hear it). NGK XR6 plugs (one range colder plug) might also help.

Fuel guage seems to be dropping at the same rate as it was before, even though I'm driving it harder.

The plugs I had in before were standard NGK ones. They were burning a light grey colour, when they should be a honey brown colour.

I've also seen a few posts about fuel pumps causing surging, so good luck in your search.

[quote="jules_1972"]Hi,
XH 4.0L Auto ute seems to surge going up hills?
Changed fuel filter, plugs, leads, air filter to no avail.
On the open road its fine, went to Auto Masters and they plugged in.
Told me everything was O.K???

Any ideas?
Also looking at changing out cam, any suggestions?
Ute has -
2 1/2" exhaust with extractors
K&N Filter
Gold Powerchip
3" air hose all way from box to manifold.

What are the torque specs for rocker gear and cam gear?




I've got an XH 4.0 l ute. Ran out of fuel once and had the symptoms you describe after that , along with hard starting after it had been sitting 4 a while.ChaNged everything you did (fuel filter twice cause i cross threaded one !!)and also slipped in a new set of injectors to no avail.
Ended up putting in a new fuel pumo (2 because it has twin tanks) and all my troubles went away..Easy to start, no more surging and revs better.

i have the same thing happening but only under slight accelleration. ive only just noticed it tho. how much is a new fuel pump or would it just be crap fuel from last fill.

prolly stinged me with water hahahhahaa

I paid $120.00 each from Auto One

my old commodore use to surge when going flat out through the gears from a standing start

By the time you beginning of 3rd it surge and throw you around like a bull, never could work out why?

6 or 8 cylinder ?

253ci V8, went nice but always cut out and surged went going through the gears with full throttle