‘93 Griff 500 cuts out for a split second on hard accel

[bergxu]

Hi gents,

As the topic states. Have had it happen twice now (oddly, only since giving the car it’s first tank of US fuel, but it’s 93 octane so shouldn’t be the issue). Anyhow, on hard acceleration, the car cuts out for a split second, I’ve done some reading on here and sounds like could be anything from throttle potentiometer to connections at the ignition coil to the immobilizer system. My question is, since parts for this car are a little bit more of a chore to come across being that I am in the US, are things like the throttle pot etc. the same parts that would be on an equivalent Range Rover or are they special for the 5.0 engine? Just would like to know because if I need to acquire any spares for testing, it would be helpful to be able to order them up from a Land Rover shop instead of bringing them all the way from the UK.

Thanks in advance.

Aaron

[rigga]

Very little is Tvr specific, and can be obtained from local sources, I had the exact same issue, and it was the ignition amp, been through a couple of my time of ownership, as the heat build up in the engine bay kills components .

[BIG DUNC]

Does the 500 need 98 RON?

Most parts will be standard Range Rover, but what isn’t should be available easily through a UK specialist.

For my Japanese car I often buy parts from a US specialist as they are cheaper than in the UK and they arrive quickly, so I expect that you can buy in the UK and get things posted over quickly. Something like a throttle pot should be cheap to post.

[bergxu]

Thanks gents, I’ve also got a Dolly Sprint and a 2500S Triumph, neither of which were sold here originally either so I make frequent orders from Rimmers and the like over there in the UK for parts for those, but figuring if I can avoid the wait time and p&p costs for some of the Rover bits on the Griff, that’ll be helpful. Presumably, the ignition amplifier and throttle potentiometer are the same ones as would be on a 3.9 Rangie then?

Also, the octane ratings are different so 98 RON should be equal to 93 US.

[BIG DUNC]

Good point about the Octane difference - I had forgotten that.

There are basically two types of ignition amps, one with three wires and one with two wires. Same as any range rover or discovery, but just check which you need. (My Griff isn't a 500, so not sure what they have).

[bergxu]

Many thanks for that. Will inspect this evening!!

[Oldred_V8S]

Normally the ignition amp starts to play up by cutting out when the revs drop, but it could be the cause.

One other item to consider is the fuel pump and associated wiring.

This summer I was pressing on a bit (hanging onto 3rd gear) behind a much slower Merc stuck in the outside lane of an uphill section of DC.
Once he did wake up and finally pull over I accelerated, only for the car to cough and splutter as I pulled alongside him. It did eventually come back to me and I managed to overtake and continue my journey.

The car behaved perfectly after that, although I was driving on slower sections of road.

Once home I thought the fuel pump sounded a bit laboured. I replaced the pump, but it still sounded the same. I connected a multimeter to the pump connections and ran the pump. I was only getting ~9v at the pump. Clearly the old TVR wiring was none too clever and with the heat of the weather and possibly corrosion somewhere high resistance was a result.

I added a supply straight from the battery through a relay that was switched by the original wiring, and I've never had the problem since. Shortly after that I took the car on a very long and hot 3k journey through the Swiss, French and Italian alps without so much as a cough from the car.

[MT tank]

... so I make frequent orders from Rimmers and the like over there in the UK for parts

only 10 miles from my home and very knowledgeable on Griff engine parts as well a MGB too.

[bergxu]

That’s good to hear. I was browsing their selection of Range Rover Classic engine items in anticipation of probably needing some goodies for the Griff.