disoc v8 sticking

[cucinadio]

Hi Guys

symptoms - on acceleration feels like there is a fuel block ..but can happen even on idol, goes fine for a while then does it again doesn't always happen ... but defiantly feels like something is sticking the surging the throtel or blocking the fuel ..

any ideas ?

cheers

[Traco]

Check usual suspects - ignition especially plug leads, injectors, TPS, MAF, fuel pressure.

Could also be sticking valves, common on D1 V8s autos using standard unleaded. Run the tank down to almost empty, chuck in in a bottle Nulon fuel system/injection cleaner and take it for an Italian tune up - i.e. rev the crap out of it in the lower gears. Then use premium unleaded and if you're mainly doing city driving leave the auto in 3 rather than D.

[cucinadio]

no worries guys.......i think after today its turned out to be a possible blow head gasket....any sure fire ways to know for sure ?

cheers

[GuyG]

The 2 ways that I'm away of are: pressure test the cooling system or check the gas content of the cooling system

[cucinadio]

what do you need to do a pressure test
or is that someing done in the workshop

cheers

[GuyG]

both were done at a workshop, but different workshops for different cars. The pressure test was for the rangie, and the headgasket had let go - there is a thread on here somewhere regarding that rebuild a few years ago.

[Flybouy75]

Hi, Im a newbie here, just bought a 94 3.9V8, it had a similar problem to your's, I done plug's and lead's, dizzy cap, coil,nothing achieved, then I removed the stepper motor, sprayed it with some contact cleaner, re assembled, and the LR god's were pleased, hasn't missed a beat..... drinking fuel, like a sailor on shore release for a day!, but going! I have pulled every single electrical connection apart, cleaned and re assembled with electrical grease, even the spark plug boot's,....... hope it help's

[cucinadio]

OK thanks guys ....changed out the fuel filter seems it all started after getting a patch of fuel from the mongeralborough....draine the radiator and ...and added a bottle of injector cleaner......seems at this stage that was the problem ..because she has been running like a dream today......i tapped the fuel filter we removed on to a brick and Ive never seen so much **** come out of a fuel filter...the fuel that cam e out of it was black as soot ....so hopefully this was the cause ...but at this stage fingers crossed all good

cheers

[cucinadio]

Hi Guys

well it seems fuel was only half the problem talk about the three amigos....

after a couple of days he started to do it all over again ....so back to square one ...
and top of that he's been over heating like a geko in sauna...
found a small leak in the top hose ...so changed it out for a new one ..btw..the boys at British off road at Forest glen are fast dam fast....thanks guys
took it down to the local ultra tune and a good mate said it sounds feels like a MAF matty...so off to British Off Road - The Land Rover spare parts specialists - Home (http://www.britishoffroad.com/) for a SH one @ $320 new buy the way are 1200 and lr 1800....changed it out and made a vast diferance...but still every now and then hesitating a little on acceleration ..thought ok might be the o2 sensers...(D1 doestn have them der matt)...still over heating a little to much for my liking .....
cleaned out the stepper motor ....a touch better on acceleration and no hesitating ATM so finger crossed...
but ran him to Bundy and back no dramas...but now as soon as you turn the air con on ..the temp goes through the roof and starts to hesitate again so ATM to mo you cant run the air con ....really got me stuffed this one ...any advise much appreciated

cheers

[PhilipA]

Clean the radiator. ie take it to a radiator place , have them pull it apart and clean out the tubes. If it is original you will probably be up for a new core.

Check that your condensor fans are working. They should be on all the time the aircon is on.
Regards Philip A

[cucinadio]

ok guys now im at wits end.......found that the advance wasnt working when sucked on ...replaced it and now the truck is right back where i satarted from .......any ideas guys ..i need to go the coast tomorrow and im at wits end

cheers

[cucinadio]

Andy...thanks for the phone call mate...will save me a lot of grif.....its enough to loose faith in the old boy..but i guess its a all about what you don't know than what you do ...all you need to do is find out ...youve help heaps mate...thanks

cheers

[cucinadio]

so the problem still hasn't been solved, after all of the advice on hear and thanks for it ...this is where l am

as stated in the beginning, it all started like I got a load of bad fuel, hesitation and bogging,....

Replaced fuel filter (pretty dirty, only three months old..

Changed out oil and oil filter,

Still no change .....

Then started to overheat with the air con on ....

Changed thermostat...and top hose (seem to be a collapsing )

Replaced MAF......still no change

Found vac advance wasn’t working so replaced...still no change

Redid the timing as suggested to 9 before top ....still no change

Cleaned out Step motor....instant clean crisp acceleration ...but only lasted for a day or two

New plugs and leads, rotor....still no change ...dizzy cap was fine

Had to drive to brissy still heavy hesitation under load (e.g. up a hill) but over heats in city in traffic turned the air con off and it came down just in time ...

Get up this morn after back from brissy and he got a huge problem like its only running on 4cyl's ...just out Of the blue after a good run to brissy apart from the bogging and hesitation..drove this morn for a while running like a dog but after it came to temp ran fine with the usual hesitation and bogging ?

Checked the voltage to the new maf and was good at 1.2v adjusted to 1.3 as per good post by Andrew...still no change

So now I'm at a loss to go next....any ideas would be helpful

Cheers

[CSK]

I have been having a similar problem, all kinds of misfires and backfires when under load. Took it to the LR specialist, they gave it a really good tune up on the Autologic and gas analyser, apparantly it was running waaaay to lean but still has a suspect sticky valve.

They sold me a bottle of Wurth 'Injection Cleaner' which also acts as an upper cylinder lubricant. I havnt tried it yet but havnt had the problem back since the tune up (a couple of days ago) and the 3.9L V8 really hauls arse now and revs right out. (I never thought I would ever be able to say that!)

If the problem does come back I'm going to get a big bottle of that Morey's 'Upper Cylinder Lubricant' and take it for the afore mentioned 'Italian tune up'!

[Tank]

Have you tried the dissy Amplifier, little black box on side of dissy or coil, Regards Frank.

[cucinadio]

Have you tried the dissy Amplifier, little black box on side of dissy or coil, Regards Frank.


thought if it was starting ..its fine ...but go on please...;)

cheers

[LOVEMYRANGIE]

Could be the TPS. The contacts wear at thecommon throttle point (ie where it spends most of it's time during normal running) and they wear out or to a point where it has a skip in it. Had this problem with mine.
To check it, do a resistance check on the TPS and very slowly turn it from fully closed to fully open. There should be a constant rate of scale all the way through without any skipping or dropout at all. Think I did a basic outline in the file I posted which is now in 'The Good Oil'.
If your fuel system was blocked, would pay to remove the fuel rail and injectors and clean the cups out in the injectors. You will be surprised how much clogs up in them.
Flush out the injectors, fuel rail and regulator with metho and compressed air as the metho will absorb any water or watery sludge in there.
Back flush the fuel lines also and with half a tank of fuel, add about 4 litres of metho.

Cheers

Andrew

[RoverP6B]

Sounds like you could have a couple of issues going on simultaneously.

Getting to the point of overheating in traffic especially when the air con is on would suggest a partially blocked radiator. Either having the radiator removed and chemically cleaned, fitting a new core or a complete assembly will see that side rectified.

The hesitation and lack of power is either fuel or electrically related.

Some Lucas distributors have a dwell angle adjuster, and these screw into a nylon piece within. Should the nylon piece split or the thread strip resulting in a constantly changing dwell angle, then the engine will behave exactly as yours is doing.

Ron.

[cucinadio]

Have you tried the dissy Amplifier, little black box on side of dissy or coil, Regards Frank.


my amp is situated below the coil ....i moved it recently along with the coil up under the b master...to make room for the second battery..
a few months ago it was playing Mary hell and would start and then drop out and stall in full fight ..so in the dark had a look and some of the wires were arcing out against the coil to dizzy lead ..i isolated them and thermo tape them all and no more arching ...then this all started to happen ...would the amp be still playing havoc if the cars running ...if you give it the boot its fine and then just out of the blue it starts to run like a dog again ......really now feels like its running on 4cyl's but after it heats up it flattens out and idle is smooth ...when the hesitation happens it doesn't effect the tach at all .....the tach shows fluctuations only when its running liike a dog as in feels like its running on 4cyl's

just trying to give all the info i can ....

cheers

[LOVEMYRANGIE]

but ran him to Bundy and back no dramas...but now as soon as you turn the air con on ..the temp goes through the roof and starts to hesitate again so ATM to mo you cant run the air con ....really got me stuffed this one ...any advise much appreciated

with the engine idling in park, switch on the A/C. The revs should pick up slightly or it should feel like it's idling stronger. When you switch it on, an input to the ECU ups thefuel to account for the extra load. Will have a look and check which pin it is and you can check to see the input is being made to the ECU.
If not, this maybe part of the problem as it will have more load and less fuel resulting in it running hot.
Fan clutch may also be playing up.
Long shot, but after I reread a few things.....
Cheers

Andrew

[350RRC]

OK thanks guys ....changed out the fuel filter seems it all started after getting a patch of fuel from the mongeralborough....draine the radiator and ...and added a bottle of injector cleaner......seems at this stage that was the problem ..because she has been running like a dream today......i tapped the fuel filter we removed on to a brick and Ive never seen so much **** come out of a fuel filter...the fuel that cam e out of it was black as soot ....so hopefully this was the cause ...but at this stage fingers crossed all good

cheers

Seen this before in cars and boats. Keep changing the filter until all is good. If you've got dodgy fuel (or with ethanol in it that has dislodged sludge) the new filter will block up as well, and maybe the next.........etc, until it is all caught. You never get the lot in one filter change if it is that bad.

Bet if you check the filter you've just put in just as much carp will be in it as the first.

cheers, DL

[cucinadio]

the really strange this is that even with all this going on, my trip to brissy the other day and back yielded the best fuel results Ive ever got....normaly get around 400k's a tank....but this trip got 430k's a tank...:(

cheers