got a volvo 740 with 230 k heron head with carb not fuel injected had a total breakdown had to get towed home ,replaced distributor cap and rotor as old one shot ,now starts but running lumpy and missing under load any thoughts on what it could be ,steve uk england

the big brick is now rolling again new dizzy cap ,rotor and hall sensor plug re fixed ,thanks one and all for help steve ,not many 740s left in uk since goverment scrappage scheme to take older cars off road ,think i will stick with the old girl at least i can work on her and fix cheers

If all the proper looms and the small plastic holders on the cam cover are not in place, the wires can short to each other or to the engine.

If you see a funny washer under a couple of cam cover bolts, they should contain plastic clips to hold plug wires.

The wires in their proper placement should not go nearer than 1/2 inch from other wires or metal parts.

I purchased a 740 that had a piece of a plug wire about the size of a pea was completely burned away, the wire had a hole in it, but the car ran pretty well.

Check to see if the coil wire goes through a plastic clip on the firewall - one of our cars had a wire cut by the clip

thanks still working on 740 problems ,luckily ive got a trusty 240 1993 estate to rumble about in which is a beautiful bonus ,steve

found loose connector at back of distributor when timing the car ,will have to fix ,have ordered a spare on e bay is this a common problem with the hall effect dizzy ,the car is a b230k heron head 2.3 running a pierburg 2b7 carb a rare bird but i am in uk its a 1991 estate thanks steve

How are the spark plugs, plug wires, firing order, timing belt, compression, carb condition, fuel supply, etc. ?

Greg

compression ok good fuel supply changed spark plugs and distributor cap and rotor just wondering if it could be the hall effect distributor playing up took her out for a run first 2 miles running like a train then goes into hiccuping mode any thoughts people ,steve

Is there a difference in the coil resistance between cold and hot ?

ive just swapped the coil for a good one and still getting the same symptoms car starts on button and under load ie driving it is hesitating but better than the no start until i replaced the distrubutor cap and rotor ,steve

When have you last replaced the fuel filter? The carb version only costs a little I think. With a clogged filter the carb won't have enough fuel under load.

Amarin.

Carbureator?? What is that??Ancient?/Clean off all grounds maybe that there might be relief there.