Hesitation under full throttle.. Better on LPG ?

Got the 3.9 out on the road today for the first time since i bought it.

Hesitates throughout the rev range under full throttle whilst running on petrol but still gets up the rev range failry decent but its definitely holding back somewhat.

Filled it up with LPG, runs much better but the hesitation seems to still be there albeit not as bad...

Now the other day, i tried to get the plugs out to clean them up and gap them etc.. HT lead came right out of the cap and my socket set wouldnt fit round the spark plugs due to the tiny gap between plug and head. Repaired the HT lead as best i could.. Running seemed somewhat the same..

two of the leads are mismatched (different brand) and look cheap, rotor arm and dizzy cap have seen better days aswell.

Obviously i will change the plugs, leads and distributor/cap asap but im thinking, wouldnt the problem im getting on petrol be magnified whilst on gas ?

Thats whats confusing me.. Obviously a new fuel filter, yes, but it still a little reluctant to boogie when on gas...

Any info or anyone have the same problem or similair that can help me out?

Cheers guys. Pilla.

Sounds to me it doesn't get the fuel/ air it needs on full throttle. But I could be wrong.

Then again how often do you need full throttle with a 3.9 V8. I don't.

Better leave it for now and investigate the engine's behaviour for a while. Jumping to conclusions can lead to additional problems on old cars ( plug leads)

FlyingDutchman said:

Sounds to me it doesn't get the fuel/ air it needs on full throttle. But I could be wrong.

Then again how often do you need full throttle with a 3.9 V8. I don't.

Better leave it for now and investigate the engine's behaviour for a while. Jumping to conclusions can lead to additional problems on old cars ( plug leads)

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Well im going to replace the leads, dissy cap and rotor as they are due to be changed, it can only help with the running i suppose.. Also filters and oil, see if it livens up after a basic service. Could be down on one pot as one of the leads has tape round it..

New plugs BPR6ES and Genuine bosch leads fitted, runs like a dream, although idle has a mind of tis own now but its ok... Revs effortlessly now, old leads were damaged, split, cracked, mismatched etc...