Thread: 97 disco

Have a look art the rear of the plenum chamber, maybe the hoses have come loose, there is a little plate hidden behind there, there is one hose is vacuum to the fuel regulator and the thick hose goes to the throat on the plenum. if these are disconnected it can cause engine hunt, stall ect.

Originally Posted by MR LSD

runs like a pig on gas and petroll and it is hunting bad dont think the gas that had been fitted was set up right arrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr

1.Can you take a close-up picture or three of the gas set-up?
2. Do you have a multi meter and know how to drive it?
3. Have the timing/plugs/leads been changed for gas?

Will give suggestions as soon as I see what you have.

[Qyet UOTE=bee utey;1422048]1.Can you take a close-up picture or three of the gas set-up?
2. Do you have a multi meter and know how to drive it?
3. Have the timing/plugs/leads been changed for gas?

Will give suggestions as soon as I see what you have.[/QUOTE]

Thinking it would have dual timing or at least should????
what plugs should I be running? It does have new NGK leads. As for timing not sure yet... what should it be?
Only just picked it up - it is missing very bad while idling. It does not miss when under load but it misses on over run. Today it back fired and blew the air box apart, also blew out the metal gauze in the AMF. Not happy. New gas set up - don't know who fitted it but have been told that it has been back and foward so many times to be fixed and they could never get it right. Even to the point where it did have multi point gas on it now it's just got suck in gas. I'm thinking I should just pull it all off and start again!

Thank you if you can help! I'd be so appreciative!
It's hard to ascertain what exactly needs attention when it runs poorly on both gas and petrol you know?

Originally Posted by MR LSD

Thinking it would have dual timing or at least should????
what plugs should I be running? It does have new NGK leads. As for timing not sure yet... what should it be?
Only just picked it up - it is missing very bad while idling. It does not miss when under load but it misses on over run. Today it back fired and blew the air box apart, also blew out the metal gauze in the AMF. Not happy. New gas set up - don't know who fitted it but have been told that it has been back and foward so many times to be fixed and they could never get it right. Even to the point where it did have multi point gas on it now it's just got suck in gas. I'm thinking I should just pull it all off and start again!

Thank you if you can help! I'd be so appreciative!
It's hard to ascertain what exactly needs attention when it runs poorly on both gas and petrol you know?

Spark plugs: Bosch WR7DC+ (my favourite) or NGK BPR6ES, gapped at 0.7mm. This is critical. Don't asssume plug gaps are about right.

Spark plug leads: what you have is OK so long as they are the new spiral core type, just don't cable tie them together in a bunch. Separate the leads physically by around 10 to 30mm. This reduces cross firing.

Timing 10 degrees BTDC at idle. It will handle petrol at this setting. If in doubt use premium petrol. Don't worry about dual timing.

Missing: it sounds like you have a vacuum hose off somewhere or a manifold leak. Check for hoses and gasket leaks. Use a piece of garden hose etc. as a stethoscope. Use a spray bottle to squirt water along gasket edges and listen for sucking noises.

MAF gauze, it will run OK without it.

Air cleaner: find an early Disco/3.9 RRC metal cylinder type air cleaner, it will remain intact during a backfire. Until then fasten down the lid of the plastic box with an octopus strap.

Originally Posted by bee utey

Spark plugs: Bosch WR7DC+ (my favourite) or NGK BPR6ES, gapped at 0.7mm. This is critical. Don't asssume plug gaps are about right.

Spark plug leads: what you have is OK so long as they are the new spiral core type, just don't cable tie them together in a bunch. Separate the leads physically by around 10 to 30mm. This reduces cross firing.

Timing 10 degrees BTDC at idle. It will handle petrol at this setting. If in doubt use premium petrol. Don't worry about dual timing.

Missing: it sounds like you have a vacuum hose off somewhere or a manifold leak. Check for hoses and gasket leaks. Use a piece of garden hose etc. as a stethoscope. Use a spray bottle to squirt water along gasket edges and listen for sucking noises.

MAF gauze, it will run OK without it.

Air cleaner: find an early Disco/3.9 RRC metal cylinder type air cleaner, it will remain intact during a backfire. Until then fasten down the lid of the plastic box with an octopus strap.

thank you wish you wer here to have a look see so what to do about the back fire or is this just aplug and lead thing thank you

Originally Posted by MR LSD

thank you wish you wer here to have a look see so what to do about the back fire or is this just aplug and lead thing thank you

Backfires happen because people don't understand how to tune/prepare gas cars. Just start with the above instructions and see how you go. When I know what your gas system looks like (hint, a pic or two would be nice) then I can advise further...

ok update. new leads, new plugs, new cap, new rotor, runs lovely on petrol and runs good on gas but revs only 550 rpm and roughly revs at 750 on petrol smooth. How do I set timing when there is only a tdc mark on timing cover? thank you
oh system is made buy AEB

The crankshaft pulley has the degree marks. Mark up TDC and the 10 degrees "before" marks with a white marker, and line it up with the timing pointer at idle. Raise the revs ( to about 2000 rpm) both with and without the vacuum advance hose connected to the distributor. You are looking for centrifugal advance and vacuum advance. If there is no difference with the vac hose on/off you will need a new vacuum advance capsule at some stage.

Oh and AEB make the electronics, the converter will have a brand name probably different.