Topic: help me with a broken v8 (Read 1225 times)

jaysastud · « **on:** November 15, 2007, 00:13:01 »

my 3.5 v8 disco is playin up badly.it was running for 2 or so mins then dying,then wait 30mis or so then worked again.so i changed the leads,rotor arm coil and cleaned up the fuel pump and all seemed ok.did a couple of small 5mile ish trips and great.then did a 30 or so mile trip and great,or not now cant get home.it starts enough to drive around five foot then dead again.seems to run if you take out the rotor arm and wipe it,butnot always.another tat rotor arm?stuffed dizzy?i need sum idea!ive got a place to crash for the night but really need to sort it ASAP!so any ideas would be great,or a mechanic in sandy(bedfordshire) who would take a lok for free!
thanks in advance!

disco-v8 · « **Reply #1 on:** November 15, 2007, 01:18:22 »

mmmmm could be anything realy.... not enough info to dignose it realy....

fair enough there alot more electrics on engines now adays but, basicaly you need 4 things to run an engine

1 air
2 fuel
3 compression (sometimes even with out will run a V8 ) so dont worry
4 a spark

first id check the plugs... take them out rest them on your engine so its got an earth then turn her over and see if there is a good spark

will doing this if youve left you main fuel pump fuse in it will try and pump fuel into the cylinders so smell for fuel aswell

also check at the back of yor plenumto see if any small hoses have popped off, because even tho you need air to run the engine too much can stop it running

like i said cant realy say much as not enough info been given

and im sure some 1 will come along to slate what ive just said :?

lurch_917 · « **Reply #2 on:** November 15, 2007, 04:10:17 »

did you change out the dissy cap aswell ??? might be this check the center post this might be worn they sometimes jam up

lurch_917 · « **Reply #3 on:** November 15, 2007, 04:19:11 »

what is it with you and your v8 ????? your allways breaking it some how

jaysastud · « **Reply #4 on:** November 15, 2007, 10:18:45 »

i wouldnt say im always breakin it.its just kinda all the same problem never really sorted out i think?anyways i dont break it,it breaks itself!i just drive it!!

jaysastud · « **Reply #5 on:** November 15, 2007, 19:49:53 »

ok it now wont run at all!what should i do?bite the bullet get it towed home and get a mechanic??any ideas much appreciated.
cheers

disco-v8 · « **Reply #6 on:** November 16, 2007, 02:00:51 »

well if you need it ASAP then yeah go and throw your money away but personly id have a mess first

is it even trying to start or is it compltely dead????

still not giving much feed back so just going to have a stab in the dark

turn the ignition on...... can you hear switch on for a few seconds???

push on all the HT leads both ends to see if everything is on ok

look in the cap to see if the contact points are black with a horible burnt bit on, if not then its ok... same with the arm

unplug all your main electical sensors and look at how good the plugs look then fitt again... theses are
air flow meter
potentiometer (the bit with 3 wires where your throttle is)
lambdas (if its got them)
injector plugs
dizzy contactor plug (two wires that come out of the dizzy)
ignition amp (might be biult onto your dizzy or will be near the back of the pass head light)
coil

ANOTHER THING YOU CAN CHECK IS THE MAIN EARTH CABLES...... there should be a smaller one that goes from the passenger side of the engine at the front near the bottom corner, upto the coil....
... but the main one that you need to check is the one that goes from the body near the battery tray to the chassis near the starter motor... as when the starter motor is turned on it draws alot of current so this earth cable must be fitted near the batter and starter to ease the flow of current....

it amassing what happens to your engine when this isnt attached, i forgot to fit mine again and it ran ok when cold but wouldnt even idle when it was warn, had to keep it at high revs so it wouldnt stall..... it was ok sometimes and bad other... fitted it again and vrrrroooooooooommmm V8 back to life

DONT BELIEVE ME!!!!!!! JUST TAKE IT OFF, AND TELL ME WHAT HAPPENS

jaysastud · « **Reply #7 on:** November 16, 2007, 13:10:24 »

cheers for the advice.the dizzy is fine its brand new all looks fine inside,rotor arm is fine once again new and looks fine,leads are all new,gona put on new coil and plugs later on,so see how they fair?checked all electrical connectors/snsors all clean connections and attached.it looks like my main engine earth goes to the inner wing near the coil,is this ok?she does turn over well but just doesnt seem to go!really lost on what it can be,at least its the weekend so can have a good play and try to sort her!dont really wana get a mechanic,as it will cost me an arm and a leg,which will be rubbish to get it sorted then not have arm or leg to drive!lol!really though cant see anything broken or that looks disconnected,or bad connection,so im relly stuck!

Budgie · « **Reply #8 on:** November 16, 2007, 15:36:36 »

You seem to have gone for the ignition side rather than the fuel side, is there any reason you suspect the ignition system to be at fault or is it just the easiest bits to check first?

Are you getting fuel to the injectors?
When you've been turning the motor over, remove one of the plugs and see if it's wet. This will tell you if fuel is getting to the cylinders.

Can you hear the fuel pump running when you initially turn the key?
You can lift the rear carpet and soundproofing, in the middle of the rear floor there is an access cover to the fuel pump & fuel pickups. Make sure there are no leaks. Also take the fuel cap out and see if there is any suction when it's released, you may have a blocked fuel tank breather.

When was the fuel filter last changed?

Are you seeing a spark at the plugs and have you checked that the leads are on the right terminals on the dizzy cap?

That should keep you going for a bit.

jaysastud · « **Reply #9 on:** November 16, 2007, 15:41:00 »

IVE HAD THE FUEL PUMP OUT AND ALL SEEMS OK CLEANED IT UP WHILE IT WAS OUT ALSO HAD THE FAEL PUMPS DISCONNECTED AT THE ENGINE AND THERE IS FUEL THERE.SO IM STUMPED IF ITS THE FUEL SIDE OF THINGS?

disco-v8 · « **Reply #10 on:** November 16, 2007, 17:45:35 »

there should be the main earth near the batter that goes near the starter...

just having the single earth going to the coil isnt good enough.... this is the problem i had, awhile back aand didnt think that 1 earth would affect it, but after been told by my dad (whos an electricain) that you need another good earth....

have you got a set of jump leads???? or thick cable????

just attach one end straight onto the negative, and the other onto the chassis (make sure it clean and a good conection) somewhere and as close to the starter as possible....
if this doesnt help then try an ECU rest, take the battery off for 10mins then try it again, if it still doesnt help then you know its not the earthing problem... but its deffinatly worth a go

jaysastud · « **Reply #11 on:** November 19, 2007, 16:53:25 »

ok all ignition parts replaced except amplifier on side of distributor.still not relly working.it seems to start as and when it sees fit.it turns over fine but just wont go!keep checking the swpark its intermitent.one time it sparks fine the next no spark at all!im rel confused,and truckless!could the amplifier on the side of the distributor be faulty?are they hard to get?how much are they?if anyone has any ideas what my problem could be please,please let me know!
thanks people!

discodug · « **Reply #12 on:** November 19, 2007, 19:23:52 »

Have you changed the spark plugs.V8's don't like wet plugs.ie fuel going in but engine not firing wetting the plugs.Had this problem with my old range rover changed the plugs and all was fine.

jaysastud · « **Reply #13 on:** November 19, 2007, 19:59:10 »

yeah mate put in new plugs.still no joy.gona try this litle amplifier thingy on the side of the dizzy if i can get one its the only thing i can think of!

discodug · « **Reply #14 on:** November 19, 2007, 20:09:36 »

Just a thought what igntion parts did you use?Use Genuine or lucas and not own brand parts.
Have you checked that the injectors are opening allowing fuel into the combustion chamber??? is the fuel returning back to the tank ie fuel pump working correctley.I know you say that you have fuel at the engine side but this could have been there before??

saintsboy · « **Reply #15 on:** November 19, 2007, 21:13:00 »

just a thought do you have a immobilizer on it

jaysastud · « **Reply #16 on:** November 19, 2007, 22:13:06 »

cheers guys.yeah immobiliser is fine and fuel pump is working correctly there is the return as there should be.cheers

disco-v8 · « **Reply #17 on:** November 20, 2007, 01:05:41 »

just of thought here so might have nothing to do with it!!!!!

have you had the dizz completely out at anytime from when it was working ok????

just thinking you may have pulled it out at one point then thought you put it back in the rite place but have got it 180 degrees out (i did this once )

just check that its timed up rite and that the dizzy isnt loose and trying to rotate off the correct timing point!!!!

oh i hope it aint ur amp as i just priced one up today at craddocks and they said Â£230 lets hope i never need one

Range Rover Blues · « **Reply #18 on:** November 20, 2007, 13:01:05 »

I think at that price I'd be converting to the RPI amp as it's half the price and gives a better spark.

jaysastud · « **Reply #19 on:** November 20, 2007, 15:09:18 »

got a price from LR in cambridge today,i can get discount there and they will do the amplifier for just over a hundred quid.havent got one yet as i noticed a loose conector on a small wire off the coil,have taken out the conector and put in a new one and she firred up first time.not sure if maybe as i have had the dizzy and coil off so much after replacing all the halfrauds tat,that maybe i cought the connector at some point and pulled the wire slighty out.not sure only time will tell if she keeps running!ill keep you informed and if it goes wrong again ill be back for more advice!thanks guys your help has been VERY much appreciated!thanks again!

discodug · « **Reply #20 on:** November 20, 2007, 15:40:06 »

Lets hope this sorts everything out :D

Rossko · « **Reply #21 on:** November 22, 2007, 01:33:48 »

Those amps on the side of the dizzy do play up, in an intermittent way. You should be able to get a pattern part from a factor for about Â£25; don't be suspicious of pattern parts here , its the rotor/caps around that are causing grief.

You also said "immobiliser is fine". Don't be too sure - I have looked at a Disco intermittent runner, sometimes good sparks sometimes not. On checking the voltage supply at the coil it varied, sometimes 6 volts sometimes a full 13v. Everytime the car was locked and unlocked it came up different :shock: Fault was the wretched spider module inside the dash - somewhere around here you'll find how to bypass it. As a get-you-home you could try hotwiring coil + directly to the battery.

cheers, Ross K

Disco Matt · « **Reply #22 on:** November 22, 2007, 15:40:35 »

Land Rover will sell you a cable to replace that alarm spider thing for about Â£5 - part number is AMR4956. It's a tedious job replacing it as you have to take the centre of the dashboard out (LR presumably thinking that the spider would be safe from unwelcome attention if buried there) but you only have to do it once.

The problem (for anyone who's not come across this already) is that the spider is on top of the heater, so it gets cooked and frozen. Eventually this leads to dry solder joints in the circuitry inside it, which cause the starting problems. You can resolder the dud joints but I wouldn't bother - you'll only have to take the whole lot out again if it has a relapse!

Don't pull the cup holder out while dismantling the dash. I did. It's a swine to get all the gearing and springs realigned after so it works properly!

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AuthorTopic: help me with a broken v8 (Read 1225 times)