4.5 GRX Loss of Power - Petrol Pump as Suspect?

[SJBS]

Hi All,

I'm a relative new Trol owner (98 4.5 GRX with approx 200k on the clock). The Trol is very nice but every now and then when accelerating it "sluks" and then pulls off slowly. When driving at speed over a hill, she also tends to loose speed significantly.

I have done some research on the net prior to purchasing thus would be expecting the ptrol pump to be the proble/part of the problem... I would have taken her to Graham, but the petrol alone would be R2000 as I'm in Ellisras...

The picture below is what Google is telling me that I'll be finding in the tank..



Some questions:

1) How do you go about measuring the delivery pressure of the pump? I see it is supposed to deliver the 3-3,5 bar.

2) I have noted that some have replaced the pump with the generic Bosch/SD Elecrical from Midas/Autozone (3bar petrol pump). I havereceived a quote of R400 yesterday for a Bosch. See Van Niekerk mentions replacing pumps with normal Bosch 3 bar pump and replacing the Pump with generic Bosch/SD Electrical/Generic Any issues with this?

Marino4x4 recommends also with some pics:
The pump is a SD Electrical Pump, stock number SD43070. I found nothing on the net about these pumps. It must be able to deliver 3.5bar, according to Frans's post. The specs on this one is 3bar, but I was assured that it is higher than this. The specs also show that the pump is used is Nissan and Toyota. I assume that this is for Patrols and Cruisers. It is not a X-Trial pump. Have serviced mine, and it is much smaller. By the way the pump dimensions is 100 mm long x 50 mm diameter.

3) Is the replacement really as simple as indicated below. Any special notes/precautions or special seals/spares needed to complete the work - I'll be tackling this over easter Weekend?
From the Aussie site:
How to replace petrol pump
Trap door in rear cargo area, undo that and theres access to the fuel tank
Disconnect the 2 fuel lines, mark them somehow,unplug the wire harness,just unclips,then undo the half dozen screws and pullout the fuel sender/fuel pump unit
Inside the plastic type cover is the fuel pump

The factory fuel pump has 2 tabs with holes , that wires are screwed to ,the wires have threaded ends ,screw goes thru tabs and thread into wires
Replacement pump mite NOT have this style ,and have bolts, easy fix carefully drill out the tabs on the wires (with the threads) so the wires can then be bolted to the replacement pump
That takes the longest time, as well, ya wanna be carefull not to stuff the wires with the drills power, so slow and steady there
Wire it up,then refit it
Just a simple reverse of the removal
Shouldnt take anymore than say 2 hours, with the slight wire tab alteration

4) Also, what part is actually regulating the pressure - the pump or a seperate regulating valve? If it is seperate, where is it located?

5) Lastly, where do I find the petrol filter for the Trol?

6) Thanks to all the info regarding the MAF sensor, I will check that out as well. (Clean and check voltages)

Any owners that have done the replacement already with the non-Nissan pump, please let us know of your success or any issues experienced.

Thanks
SJBS

[Tinus lotz]

Speak to marino he put some pics of one that works if you want I can send you Graham cummings no he will gladly help u over the phone

[SJBS]

Thanks Tinus,

I have PM'ed Marino & VanNiekerk already. Jorrie gave me Graham's no, will contact him during the week...

[Marino4x4]

Hi Steve

Hope I can answer all/some off your questions.

1) I could not measure the pressure from the pump. I just assumed that the pressure of the original pump is not correct due to the lack of power. I had to gear back to 3rd gear on some uphills. 80km/h, Not fun. Since changing the pump I can actually accelerate up hills I had to gear back on.

2) I replaced my pump with the SD electrical fuel pump. It got the same dimensions as the original pump. The Bosch pump I think is a bit smaller. The SD pump fits nicely into the plastic basket of the original pump. The electrical connections is not the same. The one side of the pump has a 4mm stud and the other side a 6mm stud. I had to drill the positive and negative connections according to the different sizes. Can not remember witch is witch. I connected the wires and sealed them with Pratley Steel. Was not to sure if the petrol will cause a short circuit.

3) Every thing is basically covered in the process described. Just open the petrol cap before removing the pipes. There will be some pressure in the tank and if you remove the pipes before releasing the pressure, it pisses your howl garage floor full of petrol. Done that twice!!

4) I am not to sure about the pressure regulating you are talking about. The pump delivers the petrol to the motor at a constant pressure. The access petrol is fed back to the petrol tank. This is one of the pipes that enter/exits the tank. The pressure control should be in the fuel injection system.

5)The petrol filter is under the drivers seat under the car. It got a small cover plate that you need to remove. You will see the petrol pipe is routed along the chassis. Fram and GUD makes a filter for the Patrol. Fuel Filter GUD E13 FRAM G4777

If you have any other questions please feel free to post them here. I will try and answer them as soon as possible or someone more knowledgeable than me will assist you. It is not rocket science.

Hoop dit help en my engels is verstaanbaar.

Groete

[SJBS]

Thanks Marino,

Wardeer jou tyd om al my vrae te beantwoord.

[SJBS]

OK - finished the job over easter and just came back from a trip to the bush ....

Some feedback:

1) The replacement pump was another make (can't remember the exact name, but our Midas did not have the SD on their system but had this 3 bar 100mm x 50mm Toyota/Honda inside tank replacement), but is working fine. I replaced it first and it made a difference, but not to the extent that I expected.
2) After a short test drive to check the workign of the pump, I quickly replaced the fuel filter. A guaranteed way to be sprayed with hot petrol is to remove the hose while under pressure! This was after the test drive and the petrol was really hot! Anycase, I found the filter was a) the wrong way round and for all intent and purposes blocked solid! I replaced the filter quickly and now the 'trol pulls like an Ox! I see this is quite a common problem being experienced. As evidence by Similar problem of Lost Power on a 4.8GRX

Thanks to all who have assisted.

[David]

Glad you are sorted Motto of the story - start with the cheap stuff!