Fine when stationary - chugs/no power when driving

Hi all,
Recently acquired a LandRover defender 90 - built to be a competition vehicle years ago- I’m trying to get it going properly again. It’s a mix match of different Land Rover parts but it’s been done by LandRover over the years.

Current specs: 1998 300tdi chassis - 1971 rover V8.

Up to this point I have:
- changed leads
- distributer cap/ arm
- new coil
- new plugs
- tuned SU HIF44 carbs

The main problem I’m having is that when stationary- I can put my foot on the throttle and it seems to rev through no problem (note every now and then exhaust backfire from rear of vehicle)

When on the road however, I can barely put my foot 10/20% down before it chugs and looses power / hopping along unless I really feather the throttle.

There is a pungent smell of petrol toward the rear of the vehicle at all times currently.

Twin SU HIF44 carbs have been seen by a mechanic and are recently tuned.

What could be the most likely cause of these problems? Fuel smell/ and chugging along road no power/hesitant power.

If you need any more info or pictures please let me know! Appreciate any help in advance!

Thatbeatenlandy said:

Hi all,
Recently acquired a LandRover defender 90 - built to be a competition vehicle years ago- I’m trying to get it going properly again. It’s a mix match of different Land Rover parts but it’s been done by LandRover over the years.

Current specs: 1998 300tdi chassis - 1971 rover V8.

Up to this point I have:
- changed leads
- distributer cap/ arm
- new coil
- new plugs
- tuned SU HIF44 carbs

The main problem I’m having is that when stationary- I can put my foot on the throttle and it seems to rev through no problem (note every now and then exhaust backfire from rear of vehicle)

When on the road however, I can barely put my foot 10/20% down before it chugs and looses power / hopping along unless I really feather the throttle.

There is a pungent smell of petrol toward the rear of the vehicle at all times currently.

Twin SU HIF44 carbs have been seen by a mechanic and are recently tuned.

What could be the most likely cause of these problems? Fuel smell/ and chugging along road no power/hesitant power.

If you need any more info or pictures please let me know! Appreciate any help in advance!

Click to expand...

Have you checked advance/retard is working?

Turboman said:

Have you checked advance/retard is working?

Click to expand...

I haven’t no… This in terms of ignition timing etc?
(I’m no mechanic but quite handy and keen to learn all the time so please excuse my ignorance on the thread!)

and fuel smell will be a leak, which should be found as soon as

freelance said:

and fuel smell will be a leak, which should be found as soon as

Click to expand...

Even if not present when engine isn’t on? Sorry if I confused matters in my original post. It’s present at all times when engine is running sorry!

Is it points or electronic?

kermit_rr said:

Is it points or electronic?

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The fuel pump? It’s a FACET electronic fuel pump. Hope that’s what you were asking

Thatbeatenlandy said:

The fuel pump? It’s a FACET electronic fuel pump. Hope that’s what you were asking

Click to expand...

I was asking about the ignition whats in the distributor?

kermit_rr said:

I was asking about the ignition whats in the distributor?

Click to expand...

Haha sorry! It’s points! Cap and arm replaced recently by mechanic

Thatbeatenlandy said:

Haha sorry! It’s points! Cap and arm replaced recently by mechanic

Click to expand...

Check your points, the contact area should be clean and smooth, if not then further investigation required.
Have a look inside the cap, that should also be nice and clean.
Assuming you have a condenser/capacitor next to the points, that can cause the issue you're experiencing

Thatbeatenlandy said:

Haha sorry! It’s points! Cap and arm replaced recently by mechanic

Click to expand...

Why was the cap and arm replaced?

Thatbeatenlandy said:

I haven’t no… This in terms of ignition timing etc?
(I’m no mechanic but quite handy and keen to learn all the time so please excuse my ignorance on the thread!)

Click to expand...

Yes. Advance/retard on the distributor.

kermit_rr said:

Check your points, the context area should be clean and smooth, if not then further investigation required.
Have a look inside the cap, that should also be nice and clean.
Assuming you have a condenser/capacitor next to the points, that can cause the issue you're experiencing

Click to expand...

Thanks mate will check this out today and have a good look at it. Cap and arm were replaced because old one looked rough and just thought it wouldn’t harm having a new one.

Turboman said:

Yes. Advance/retard on the distributor.

Click to expand...

Thanks mate. Is there a simple way to check the advance/retard is working as it should be? Anything to look out for? Thanks!

Thatbeatenlandy said:

Thanks mate. Is there a simple way to check the advance/retard is working as it should be? Anything to look out for? Thanks!

Click to expand...

Check the vacuum pipe is connected and not leaking would be a start.

If the unit isn't working, the engine won't rev up very well.

Is there oil in the carb dash pots?
Is the float level correct?