Juddering up hill

[waltraud]

83 DG Westy with camping load and 4 people. Generally runs v well. When going up certain hills not necessarily steep it can start to judder a bit and get more noisy. Runs lpg smoothly.
Im thinking: check cv bolts. Engine mounts? No clutch slip but clutch is certainly 6 or so years old since I got the van. Electrical system parts, plugs, oil, carb running well.

What might worn engine mounts cause?

[Smosh]

Sounds like it is hesitating under load.

When was the last service?

I would check the dizzy and rotor for signs of wear. check the fuel filter is clear and the air filter. then move onto spark plugs & HT leads. If it still is doing it, it may be that your ignition coil is getting tired and on its way out. But my van ran a lot happier when I replaced the items above (not coil).

These are quick and easy to change and check and cheap. I would start here.

[waltraud]

Thanks. Quite recently services with plugs, cap and rotor. Good pojnt re fuel filter- will check this.

[Flyingchunk]

Breather pipes constricting under load?

[Oldiebut goodie]

Reading the 1st post, OK on lpg up hills but shuddering up hills on petrol - is that what is meant?. Points to petrol fuelling system to me not anything else as all the other things mentioned in reply are used when running on lpg also. Likewise OP why would cv joints/engine mounts not cause the same effect on lpg?
Bit of a scattergun approach on diagnosis here?

[waltraud]

Thanks- sorry for the confusion, possibly because I'm not sure if it runs differently on petrol or LPG regarding this symptom. I will check.

[Smosh]

Reading the 1st post, OK on lpg up hills but shuddering up hills on petrol - is that what is meant?. Points to petrol fuelling system to me not anything else as all the other things mentioned in reply are used when running on lpg also. Likewise OP why would cv joints/engine mounts not cause the same effect on lpg?
Bit of a scattergun approach on diagnosis here?

I wouldn't of said it was a scattergun approach at all. I don't know much about LPG systems, but as no one else replied I thought I'd try to help. I think I gave an approach that actually followed some logic (albeit mine! ) starting with simple checks and cheap fixes. but as I just said, I don't know lpg and was working under the assumption that a weakened spark might be adequate for LPG but not for petrol. it didnt sound daft to me at the time!

[marlinowner]

I'm open to being corrected, but I think LPG is more sensitive to ignition problems than petrol is, so if its smooth on LPG the ignition is OK, or alternatively if its hesitant on both LPG and petrol then ignition is likely suspect.

[waltraud]

.......thanks all, in fact the coil is also pretty new but ht leads are a few years old so I might replace them for good measure. I'm not sure how much the fuel type matters in this case but am interested to see if it makes a difference.

[waltraud]

Resurrecting this thread as symptoms prevail but only at certain times. Most notable on motorway in 4th pulling from 45 or so and not dependent on fuel type. I have replaced engine and gbox mounts but not cured! Next to check tightness of all cv bolts.