Maintenance of XJ40, Sov.........................1st to -3rd March, 2014

Reg No XIB 085-- Vin No SAJJHALD3AA/631596; Eng No EPCMA134598

Works = Remove engine oil, oil filter, TPS (Potentiometer),disconnect blue TPS harness, clean out TPS. Clean electrical harness &lubricate for ease of refitting as they can be brittle.

1. Remove engine oil from sump using 3/16 socket.---approx 8 litres ,discard

2. Remove oil filter, use plastic bag around thefilter to catch excess oil from filter.

Note, can bevery tight so ensure anticlockwise with oil filter remover –short handle type..

3. Tie off rubber hose –A/T or A/C which otherwiseobsecures view of underside TPS.

4. Mark on chrome ring that surrounds Mass air flowmeter(MAFM) and the TPS itself, angle of TPS for refitting. Suggest you use thecorner near chrome ring. Use extended ratchet with aprox 5mm socket

Note, use blackTex for the red TPS & white office paint (correction fluid) for the chromering.

5. Dislodge blue harness from small manifoldbracket. Disconnect Blue male harness from female and clean with expensiveelectrical cleaner. Check all 6 coloured wires for cracks in the outer wirecase and repair with insulated electrical tape.

6. Clean out TPS or buy new one (Throttle Position Pot DBC2889)at around $300US + or at 114+ GBP.

7. Suggested method of cleaning your TPS.

1. Use combo of expensive auto electrical cleaner& degreaser plus patience. 2. Fill up the TPS and empty after a good shakerepeat several times; use one spray at a time. You will see the oil residueseep out of the seals so you need to hang up the TPS for a couple of hours todrain. 3. You are also advised to use low air pressure in the main orifice ofthe TPS to force out the now oil mixture. 4.Using very soft cloth, roll into a needle shape& clean inside shaft hole. 5. Leave overnight if possible. More oil mixleakes out from seals, wipe thoroughly. 6Respraywith electrical fluid and empty quickly.

8. Re-install TPS when no further evidence of oilmix seeping out of seals.

9. The little TPS bolts are easily lost so takeextra care also, easy to cross thread. Tighten at wrist pressure only on the ratchet.

10. Re-install new oil filter with EBC 9658 (CHEAPER)wipe rubber seal with new oil again, wrist tighten only .

11. Release rubber hose. Return to enginecompartment & reconnect blue harness to female end & fix on manifoldbracket.

12. In Australia, I argue that 20-50 is the best oilfor this very large motor as the temps are well within that range listed inyour drivers manual. ( forget the Haynesbook of ????) Fill using aprrox 7 .5litres. No overfill.

13. Excite engine & check for leaks around oilfilter, any red engine light “check engine” and happy motoring saving manyhundreds dollars not forgetting the labour at $110 per hour.

MichaelPrichard

Melbourne Australia

March, 2014

 

Michael,

I've removed the address details from the top of your post.

I assumed this is your home address? Never a good idea to post that kind of personal information on a public forum.

You've had two busy and productive days on the XJ40.

Graham

 

Hi Michael, and greetings from the Coffs coast,

What a great write-up you have shared here. Worthy of some widespread "thanks" from other XJ40 and Sov owners. I must say, after some recent trolling through eBay and Gumtree as well as the trad car sales listings, there is no shortage of XJ40s and Sovs at modest prices to suit all budgets. Hmmmm ... very tempted ... but leaning toward smaller ... wife is not leaning much at all. Damn ... you see, the car is nominally for her.

Michael, you have a good writing style, so I look forward to more as you venture further. Any pics?

Best wishes,
Ken

 

re my post on TPS, vehicle is MY July 1990 sov

 

Just thought it might be of some interest to members to have some followup on a repair after it has been completed & then , submitted to readers.

I am thrilled to be able to say that the whole exercise of removal & re-installation has netted very good results in the following functions:-

1. Vehicle idles a lot smoother,
2 auto trans smoother changes,
3 fuel to kilometers (miles) ratio much better,
4. acceleration smoother.
5 convinced that at each oil filter change, remove TPS & clean.

There are technical reasons for these significant improvements but they are long winded.

Hope this is of some help as I notice that one or two members have suggested that the whole of the mass/airflow throttle be removed. That idea I think, lacks clear thought.

Michael P
Melbourne. Australia