4.8 GRX Power loss

[Rocstompa]

I have a 2006 4.8 auto that is not starting well and has power surges while driving , also seems to be searching for gears. When starting is feels as if the vehicle wants to die, after a few seconds the revs jumps and revs slightly high. While driving she is searching for gears , this can be especially felt when doing about 100km/h on the open road then she drops a gear and takes off only to change up a gear and start struggling which causes her to drop a gear again.

I had a Unichip and freeflow fitted a number of years back but have had the Unichip removed as it seemed to make the fuel consumption worse and seemed to be dumping fuel which i thing caused the manifold to crack. Other than that I have had one standard radiator go which was replaced so dont know what could have started causing this. I did change the fuel pump and filters thinking that this may have been a problem but never solved the issue.

Getting tired of my mates jokes that the car doesnt go faster and slower just louder and softer Need to get this sorted out if anyone has had similar problems.

[Kagiso II]

ECU malfunction
Dirty / low lever gearbox oil
Autobox belts slipping
Crank sensor ..
100 other things can cause that ..

Me thinx take it to NISSAN dealership and let them do a diagnostic .. Then give us the fault number.
Contact HERRIE op Safari [Kobus Pienaar] here on forum to send you a workshop manual on your car

Best of luck .. hope it is fixed soon

[Tinus lotz]

Change the feul filter first....

[Rocstompa]

Change the feul filter first....

Fuel filter and pump changed with no difference. Both were clean so I could scrap dirty tank.

[roelf prinsloo]

DET IEWERS GELEES VAN IEMAND WAT SO PROBLEEM GEHAD HET--DIE ALTENATOR HET NIE REG GEWERK NIE EN DIE COMPUTERBOX "TOR" DAN ROND OMDAT HY OOR OF ONDER LAAI.SEKER MAKLIK OM TE TOETS.

[Wilkie]

Also check vacuum pipes as they do tend to crack and there are quite a few pipes ...also those black canasters which operate your difflock...when people change manifolds the heat makes it brittle and cracks....

[Rocstompa]

Thanks guys.

Problem found. When the guys fitted a new fuel pump they never sealed it properly causing dirt and some water to enter the tank. On top of that the filter on the pump came off and was floating around in the tank.

Have cleaned all fuel lines and the tank, have replaced the tank fuel pump with a Bosch universal pump and replaced all fuel filters. I am now happy to say that the beast is back.

[hugejp]

Grrat that you found the gremlin!!

What bosch pump did you use?

Does it have a similar flow rate??

[Rocstompa]

Grrat that you found the gremlin!!

What bosch pump did you use?

Does it have a similar flow rate??

It was purchased from Midas.The bosch pump replacement is apparently a universal pump , it has no pressures or anything on the box and all it says is Bosch Electric fuel pump made in Brazil. The numbers on the side are as follows.

1St/Pc
0 580 453UNI

hope that answers your question.

[hugejp]

Thanks man!