V8 left hand bank

[disco-v8]

ok i no alot obut the rover V8 now and worship it!!!! i have nearly replace all the internals of it (except pistons, con rods and crank) and havent been running it for that long long realy about 5000 miles.....

well agies ago my viscus packed up and stopped working properly, so me the cheap skate that i am and wanting an instant fix, i put a bolt straight through it, as you can emagine this didnt help MPG and sounded like a jet engine when rev'd, but kept the engine cool......

well after awhile i got fed up with this and have just fitted a par of twin 12" spel fans and after a while the temp stayed fine but there was a slight wiff of a burny smell, but the engine didnt seem to be any hotter than it used to  :? well my engine has always seemed to run hot so i have always thought this was the norm for V8's

well after getting abit worried i noticed that from the front the left hand bank was getting hotter than the right side and that smell could be smelt from that side, so i lashed up a little thermister to the rocker cover and the left side was deffinatly hotter than the rite side, so now im confused????? when the viscuse was on throwing gallons of air a second at the engine it must av kept it cooler...


so does anyone know what the reason could be for this side getting hotter???? oh the slet smell doesnt smell like gasket

ive also just replace the air flow meter, fuel pressure regulator and all the injectors

please can someone help, but i think this one is for the mechanicly minded ones

[clbarclay]

You could have something like a blocked/restricted water gallery in the left hand bank. less water flow would mean less cooling.

Alternaively it is possible for one bank to fuel differently than the other bank (one normal an the other rick/lean). I can't remember all the fault diagnosis, but incorrect fueling can cause over heating.

[skip]

A faulty oxygen sensor could cause a lean mix on one bank.

 The ecu may not show a fault code as the right criteia have not been met yet, due to the sensor not being bad enough,

Best thing is to compare results from the senors on both banks using a multimeter, unfortunatley I haven't messed about with the 0-5 volt resistive sensors before, but i'd imagine the wiring goes,

2 white wires are for the internal heater,

2 remaining wires are a +5 volt feed and return feed to the ecu.

it's the return to the ecu that needs to be compared,.

[doris]

Hi All

I have the EFI test manual (complete test routine with multimeter) if anyones interested?

Damon

[Range Rover Blues]

I'd like a copy of that please Doris.


I have a copy of Rovacom which IIRC will tell you the inputs and outputs, ei the timing injector pulse becasue as said, the engine fires in LH and RH banks as well as having LH and RH lambda sensors.

Couple of things to try.

Check the LH and RH lambdas are not swapped over, otherwise the ECU wil be trying to correct a fault that doesn't exist.

Fit the alternative TSR into the ECU loom to dissable the lambdas

Witha the Haynes Manul for RRC you can find out which connector is the Lamda feedback to the ECU and check it at the multiplug connection.

You can clear any ECU faults by disconnecting the battery for a couple of minutes.

BTW, the engine sits closer on the LHS and if ours has the alternator on that side lke mine then it will get significantly less air over that side of the engine.

[doris]

Send me an email to thepad3 at tiscali.co.uk (substitute at for @)  and i'll attach it to a reply........  its quite a chunky pdf.

Damon

[disco-v8]

i cant see it been the lambda's the wrong way round as the wires will not go that far...

ive already done a little test with the multimeter on the lambdas and they sit at about 1volt ish and when reved and let go its shoots to about 1.5 volts... i know these should stay inbetween 1 - 5 volts but i dont no what they should be at idle......

where can i get one of those replacement risisters from which tells the ECU that it hasnt got lambdas, and where does it go?????


i know its not cuz the alternater is in the way as the heat difference is quite alot, and i no that my engine just isnt quite rite, it just seems to get to hot (but doesnt over heat) im sure that the rocker coves arent ment to get hot enough to burn you and the plneum can burn to......


like today while offroading after its been driven for a while under alot of load and then turned off, and then back on again, it has trouble idling and some times stalls, its can also do this after driving it on roads for a while


more and more help needed.... does anyone no what the 3.9 efi V8 tempurature should be when warmed up, and dont tell me what the guage says, i want a proper figure

thanks

[Range Rover Blues]

TSR or tune select resistor is enclosed in plastic and sits within a few inches of the ECU under the seat or in the middle of the dash access panel ona soft dash if it isn't still wrapped up in the wiring loom.

Change it for one from an old pre-cat equiped car or make one up, then you can disconnect the lamdas.  IIRC the sockets for them come out of the wiring loom in roughly the same place don't they?  could be wrong though.

Top of my engines get hot enough to hurt, remeber that inside the cylinder gets hot enough to melt aluminium

Lamdas probably not correct at idle as most EFi systems only run stoichiometric above idle speed and up to about 70% Wide Open Throttle.

[skip]

I'm only going by what my 94 jeep did when I was testing the lambda.

At idle and moderate throttle openings the voltage would fluctuate as the EFI system is always trying to achieve stoich, but as it's impossible to maintain due to other outside infulences it's having to constanly compensate. under sudden acceleration or WOT the mix would go rich to produce plenty of power and prevent a stumble or cough.

Here comes the guess work bit on my part, I think that because the hotwire system uses 0-5 volt sensors instead of 0-1 volt sensors, It would be able to more accuratley judge the mixture and so hold it slightly on the rich side at idle. but I would still expect to see a fluctuation in the voltage output from the sensors, just slightly higher or lower on the voltage range given by the sensor.


Disco-v8 I see on your last post that you said when you revved the engine it shot to about 1.5 volts from about 1 volt, IMO that's not doing what it should. I would expect to see much larger change in voltage. First when on the pedal with rising revs I would expect to see quite an increase in voltage. Then when off the pedal and falling revs there should be a fuel injection cut so the voltage should be sticking very close to 0 or 5 volts until revs fall to around 1700-1500rpm when fuel injection is resumed.

I am only theorising as I don't know the lucas system very well, but all injection systems operate in similar ways. My guess is your o2 sensors are shot.

Hope it helps anyway.

Pete.

[Range Rover Blues]

I'm not sure the Hot wire uses fuel cut-off during deceleration, going on what I was told about the setup of a multipoint LPG system where it is an option.

I think it could be the Lambdas are suspect, provided it is a fuel problem and not a cooling problem.

Here's a thought for you anyway, beg/borrow/steal a contact thermometer or optical/laser thermometer and check the temperature of variouos parts of the engine when it's had a run, I'll check mine for you to compare it to, ok?

[disco-v8]

god knows where im going to borrow (steel) lol one of those from!!!!!

might just have to buy something off ebay or something....

thanks for checking your temps for me RRB ill have something to compare them with then.....

im sure its not the cooling thats the problem as when i rebuilt the engine im 99.999999999999% sure that all the water galleries where clear and a new radiator was fitted....... just hope its nothing machnical inside

just bought a air/fuel guage which my olden is converting it to a high band one to work with the my 1 - 5 volt sensors


keep trying to help tho guys more heads the better on this one

[Range Rover Blues]

Next time you are passing...........



... it's only an hour away and you can hook it up to Rovacom then too.

[disco-v8]

you know what.... thats sounds like a great idea, think it will be the only way to find out.....

quick question?????

i was looking at the water thermister and fuel thermister.... and these are so close to each other they could get put on the wrong way round.....

ive got the brown plug on the water, and grey plug on the fuel rail... is this correct???

[burgerman]

Complete shot in the dark, But when you  rebiult the engine did you replace the core plugs ??  If so were any knocked inside the block ( by accident) and not retrieved ??  this would /could / does cause some local heating issues  

   I know its a long shot, but has happened in the past

[Range Rover Blues]

you know what.... thats sounds like a great idea, think it will be the only way to find out.....

quick question?????

i was looking at the water thermister and fuel thermister.... and these are so close to each other they could get put on the wrong way round.....

ive got the brown plug on the water, and grey plug on the fuel rail... is this correct???

Couldn't tell you, I'd have to check but IIRC they are the same thermistor, or at least the same value even if the packaging is different.

Do you have airconn? just that if the ECU thought the fuel was that hot it would run the fans even after the engine was switched off.

[disco-v8]

yep i did chance all the core plugs but didnt let any slip in, used a slide hammer....


RRB youve made me think abit with your last comment..... if the engine was too hot the air con fans would be always on..... and im sure they are not.... but i thought that in front of the inlet manifold where the thermastate is, there is a thermostat switch, and i thought this was an emergancy switch for the air con fans if it got too hot!!!!! or is it for something else.....


i still think ive got a problem with heat.... i recon that the engine is trying to over heat but the cooling system is doing its job and stopping it from happening, but i think it shouldnt have to try this hard to cool it

if i havent got an over heating problem why does my engine struggle to start and idles iratic when the engine is hot????

[Range Rover Blues]

Ok, if you have airconn then the temp switch in the thermostat elbw will switch the fans on if the engine is running too hot, check that this switch is working though.  It's needed becasue of the extra restriction that the air conn radiator creates.  When the air conn is on the fans will run constantly.

In addition the engine ECU can turn the fans on, if when parked up the engine temp exceeds a preset temp, or the fuel goes above something like 60 deg in the fuel rail, then the fans will come on.

Here's a thought then, how good is your vicoous fan?  do you hear it whoosing when you first start up? does it start whooshing again when the engine is getting hot?

[disco-v8]

well agies ago my viscus packed up and stopped working properly, so me the cheap skate that i am and wanting an instant fix, i put a bolt straight through it, as you can emagine this didnt help MPG and sounded like a jet engine when rev'd, but kept the engine cool....

kind of already state my viscus in my post.....


but even with the viscus super cooling my engine it does that dodgy start and idle when hot????? think this my be another problem im having but i dont know

[Range Rover Blues]

Dodgy idle when hot could be a sensor :?

[disco-v8]

yeah when i start it from cold it takes abou 1.5 to 2 turns and it kicks in straight away....

when its been driven and engine is warm it start on the flick of the key...

but when its hot after a hard day off roading or very long journey, it struggles to start, and usualy when its cold/warm the revs jump to about 1200 RPM then the stepper motor dropps that straight awat to about 750RPM.... but when hot and finaly starts it jumps to about 800/850 and sometimes revs up on down abit and nearly stalls, some times it does stall


so what sort of sensors would cause all this????

[Range Rover Blues]

Hmmm, so many possibilties.

Idle bypass stepper of engine temp sensor perhaps?