Thread: 95 Disco V8i struggling to accelerate, "bucks" a bit when taking off.

Has the in-tank fuel pump been replaced? Those were the symptoms that I experienced when the pump on my 89 V8 RRC died.

Typically the pumps last about 150,000 - mine went at 225,000.

And check the usual - fuel filter, plugs, air filter, etc

could be something really simple like vacuum line loose or cracked. Can cause same symptoms.

If you have a IR thermometer (heat gun), run it over the 8 exhaust ports on the manifolds (engine running from cold)....easy way to pick up which cylinders are missing. If ignition related, could be plugs/leads of those cylinders, or dissy cap/rotor.
Well worth replacing the fuel filter, if it's missing at idle, a quick squirt of some flammable arosol in the intake may help diagnose......should pick up if fuel related, stay the same if spark related.

As well as fuel pumps dying, the hose in the tank can also split and cause very low fuel delivery and pressure.

check plugs and leads, pull one at a time with a pair of pliers while it is idling, if the idle gets worse its not that lead or plug,if it doesn't make much of a change you have found the issue.
How long since a decent service, if a fair while replace plugs , leads, cap if worn, and fuel filter, all service items.
If the problem persists my guess its either fuel pump or air flow meter related

Thanks for the replies as this is my son’s discovery. I checked for vac leaks, checked fuel pressure (32psi) fixed the vac advance also checked the maf. I had previously pulled the plugs just after he purchased the car and they were in as new condition and also indicated that the mixture and timing was good.We haven’t been able to get the fault to happen again so I’m am wondering whether it is a fuel level issue, as a number of years ago I had a similar fault with a split gauze pickup on the end of the fuel pickup in the tank. Is this possible with the Discovery in tank pump?
We are planning on getting a replacement pump for it anyway as a spare part to carry along with the other spares. Thanks Paul.

[QUOTE=Porker;3154698]Thanks for the replies as this is my son’s discovery. I checked for vac leaks, checked fuel pressure (32psi) fixed the vac advance also checked the maf. I had previously pulled the plugs just after he purchased the car and they were in as new condition and also indicated that the mixture and timing was good.We haven’t been able to get the fault to happen again so I’m am wondering whether it is a fuel level issue, as a number of years ago I had a similar fault with a split gauze pickup on the end of the fuel pickup in the tank. Is this possible with the Discovery in tank pump?
We are planning on getting a replacement pump for it anyway as a spare part to carry along with the other spares. Thanks Paul.[/QUO had same problem spent weeks checking all the stuff was magnetic pickup in dizzy wire had broken would start then stop splutter also changed module to a bosch as lucas one has a habbit of letting you down

[QUOTE=redmond;3154724]

Originally Posted by Porker

Thanks for the replies as this is my son’s discovery. I checked for vac leaks, checked fuel pressure (32psi) fixed the vac advance also checked the maf. I had previously pulled the plugs just after he purchased the car and they were in as new condition and also indicated that the mixture and timing was good.We haven’t been able to get the fault to happen again so I’m am wondering whether it is a fuel level issue, as a number of years ago I had a similar fault with a split gauze pickup on the end of the fuel pickup in the tank. Is this possible with the Discovery in tank pump?
We are planning on getting a replacement pump for it anyway as a spare part to carry along with the other spares. Thanks Paul.[/QUO had same problem spent weeks checking all the stuff was magnetic pickup in dizzy wire had broken would start then stop splutter also changed module to a bosch as lucas one has a habbit of letting you down

Taken in a load of water contaminated fuel prior to the 2nd load he mentioned? A decent dose of Metho into the fuel Tank was always my Pre- Winter safeguard.

Need to check fuel pressure with and without the vac hose connected to regulator…… at idle fuel pressure should raise when hose is removed, drop back a bit when regulator sees manifold vacuum.
At very least, replace fuel filter.
Maybe drain fuel and remove fuel pump from tank for a visual…..could have got a dose of bad fuel.
98 fuel seems to go bad quick if left sitting, had this issue a few times with a bike (left sitting for 3 weeks from a full tank and would barely run…..drain and replace fuel and all good)