thor 4.6 v8 wont start properly ???

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mozz smith

mozz smith

Well-Known Member
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Location
tameside manchester
hi lads , I have a 2000 model 4.6 v8 thor engine petrol/lpg .
had car for 4 yrs usually starts 1st button
last 4 weeks wont fire up 1st thing in morning ?????????
its taking 4/5 turns to fire up then ok all day ..
in last week had new battery fitted ????? still same :mad::mad::mad:
had new crank sensor fitted still same :mad::mad::mad:
had new maf fitted still same :mad::mad::mad:
now im known as the re-sync guru "wich is nice :D:D but im defo no mechanic ????????:confused::confused::confused::confused:.
so ANY help would be greatly appreciated ..:):):) it seems to me that as its parked up overnight that the fuel rail is empting back to tank ????????:confused::confused::confused: please please help its driving me round the f***** bend , cheers MOZZ
 
It sounds like the petrol pump might be going south on you.

Turn the ignition key to ON so all the lights come up, wait 5 seconds and try it. If no different, I'd say fuel pump. If it fires up immediately then possibly blocked filter in the pump. Same solution, new pump.

The fuel pump runs for 5 seconds when you turn the ignition on, then it stops until the ECU detects that the engine is running by the signal from the flywheel sensor.

Peter
 
hi peter, thanks mate I tend to agree with you there but not relishing the cost of that:rolleyes::eek: but no doubt will have to bite the bullet on that ,,,I am gonna try new temp sensor today ,fingers crossed . will report back later ,,many thanks regards mozz:):)
 
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hi all, latest update , son in law just fitted genuine new temp sensor..only took 1 hour so will leave it now till in morning so will start from cold and see how I get on "fingers crossed " it will fire up on 1st button ????????? will update again in morning ,,cheers MOZZ
 
well lads good morning ,, bad news ,:eek::eek::eek: after a long cold night approx. 13 hours it still took 6 cranks to start :mad::mad::mad: . so no further forward !!!!!! any help please ?????? im now getting fed up and:confused::confused::confused::confused: methinks il'l cut my losses and get rid .. there must be someone out there who's had same problem !!!!!!! any ideas anyone ??????? cheers MOZZ
 
Fuel pump on your Thor engine 3.5 bar 52 Ibf/in (psi) there is a shrader valve on the rear of the fuel rail to check the pressure. Hard to get at but can be done.

You might check (diagnostics) Lambda and cats.

Possible other causes could be inlet manifold gasket / exhaust gasket.

ECU Temp sensor (behind the alternator) could be?

Compression check

Spark Plugs - air filter.

Air leak after MAF

A failed injector but you would get rough running missfire etc and high emissions.

Idle Air Control Valve - Engine stalls, difficult starting, raised idle speed in default condition. or lower

LPG system??

Any fault codes showing when you had it on diagnostics. ps when you changed the crank sensor did you do an adaptive reset?
 
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Not sure what the temperature sensor would do, other than change the enrichment levels for starting.

I'd be inclined to get hold of a secondhand pump off ebay and give it a try.

Peter
 
listerdiesel said:
Not sure what the temperature sensor would do, other than change the enrichment levels for starting.

I'd be inclined to get hold of a secondhand pump off ebay and give it a try.

Peter
Click to expand...

Hi Peter. I Have to disagree. The Engine Cooland Temperature (ETC) sensor (from 99). Failure may result in:
Poor cold and warm/hot start and driveability. The sensor contains two thermisters that provide corresponding voltage 0-5v. The ECM Engine Control Module uses this info to change fueling on start up and running.

Also. As stated you can check the pump pressure. And if the pump needs replacing it would be sensible to fit a new replacement. In my case I have a petrol 4.6 Thor and replaced my petrol pump a couple of years ago. To do that I cut a flap in the rear as Land Rover don't supply an easy access cover. So if I do need a new pump its easy to do but I don't know if Mozz has undertaken this in the past. I would NEVER buy a secondhand pump which is just bad economy and risky (in my opinion but you are correct it would prove if it was the pump assuming the secondhand one was good). Thor pump is one way only unlike a GEMS where there is a return line.

Mozz says there is a wiff of petrol on eventual start so thinking more on manifold gasket or leaking injector seal?? or in that area. Will be interested to find out what it is.
 
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stopover said:
Hi Peter. I Have to disagree. The Engine Cooland Temperature (ETC) sensor (from 99). Failure may result in:
Poor cold and warm/hot start and driveability. The sensor contains two thermisters that provide corresponding voltage 0-5v. The ECM Engine Control Module uses this info to change fueling on start up and running.

Also. As stated you can check the pump pressure. And if the pump needs replacing it would be sensible to fit a new replacement. In my case I have a petrol 4.6 Thor and replaced my petrol pump a couple of years ago. To do that I cut a flap in the rear as Land Rover don't supply an easy access cover. So if I do need a new pump its easy to do but I don't know if Mozz has undertaken this in the past. I would NEVER buy a secondhand pump which is just bad economy and risky (in my opinion but you are correct it would prove if it was the pump assuming the secondhand one was good). Thor pump is one way only unlike a GEMS where there is a return line.

Mozz says there is a wiff of petrol on eventual start so thinking more on manifold gasket or leaking injector seal?? or in that area. Will be interested to find out what it is.
Click to expand...

so would I Derek :rolleyes:so would I !!!!!!! :rolleyes: so no further forward , don't know what to do next !!! there is no access to tank !!!! it will have to have the tank off and am not sure to spend £340 on new pump then find out its not that ??????:(:( ive spent £375 in last week on battery - maf -temp sensor-crank sensor + labour and still no further forward :confused::confused::confused:regards MOZZ:mad::mad::mad::mad::mad:
 
mozz smith said:
so would I Derek :rolleyes:so would I !!!!!!! :rolleyes: so no further forward , don't know what to do next !!! there is no access to tank !!!! it will have to have the tank off and am not sure to spend £340 on new pump then find out its not that ??????:(:( ive spent £375 in last week on battery - maf -temp sensor-crank sensor + labour and still no further forward :confused::confused::confused:regards MOZZ:mad::mad::mad::mad::mad:
Click to expand...

Why not get someone to check the fuel pressure and diagnostic on lambdas/Cats.

Fuel Pump - only if you need it - WFX101400 WFX101100 £169 plus post vat? new Bosch on ebay?? method of cutting the boot floor on the forum
 
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hi dek , will I have to change the whole fuel rail ?????????? and whereabouts is the detail to cut hole to get to pump ,cheers mozz:):):)

ps ive tried various people to do diagnostics and none satisfactory " not sure if any of them know how to use them properly ?????????? " its just a waste of money every time to get bad advice ?????????:eek::eek::eek:
 
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hi lads still no further forward, is there a way to test fuel pump is working appart from pressure test ????????? still have to turn over approx. 6 times 1st thing in morning from cold ,seems like fuel line is emptying back into tank over night ?????????????????? answers please before I ring the scrapyard up !!!!!!!!! cheers mozz ,, p.s. is there any EXPERTS out there on the thor motronic engine ??????????
 
mozz smith said:
hi lads still no further forward, is there a way to test fuel pump is working appart from pressure test ????????? still have to turn over approx. 6 times 1st thing in morning from cold ,seems like fuel line is emptying back into tank over night ?????????????????? answers please before I ring the scrapyard up !!!!!!!!! cheers mozz ,, p.s. is there any EXPERTS out there on the thor motronic engine ??????????
Click to expand...

Hope you find an EXPERT ! this is my last and final post to you.
 
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