reorganised HT leads, car now feels lumpier and slower

reorganised HT leads, car now feels lumpier and slower

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jazzdude

Original Poster:

900 posts

152 months

Saturday 28th November 2015
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Decided to tidy up the engine bay and put the HT leads into spacers as the garage that fitted them recently left them looking like a dropped bowl of spagetti. Moved them one at a time so I think they are back in the right places. I also moved the ribbed conduit hoses around the LT leads around as they were all cable tied to the top of the distributor and checked the connections to the coil and they are tight.

The car now feels lumpier at idle and seems to have a little more vibration and about 30% slower. It is not misfiring, revs to the redline, no shunting, and with my ear in the engine bay can't I hear clicking or arcing around the sparks. It does sound a little like a Subaru though as if it is running on 7.5 cylinders (is that possible?). I checked the leads, took them off and pushed them back on again and I think they are tight on the plugs and (no shrouds), sparks resistor type.

I doubt I could put 2 leads on the distributor the wrong way round as surely the car will be backfiring and sounding terrible?

Is it possible that in my reorganization I have killed a lead? If so, whats the best way to find out which one without electrocuting myself or burning my hands?

jazzdude

Original Poster:

900 posts

152 months

Saturday 28th November 2015
quotequote all
Just had a thought, I cable tied the main HT lead from the coil to the distributor to the mass of wires that are in the ribbed conduit going to the coil, as it was too long and sticking up in the air.

Is it possible that this proximity is causing the problem?

jazzdude

Original Poster:

900 posts

152 months

Saturday 28th November 2015
quotequote all
Is it possible that the distributor cap has been disturbed with all the pushing and pulling, would that cause the lumpiness?

jazzdude

Original Poster:

900 posts

152 months

Saturday 28th November 2015
quotequote all
blitzracing said:
This is how it should be- the routing and spacing is to prevent cross firing between the HT leads. Double check you have not swapped two by mistake.



That is the chart I used, although the no 1 position on my distributor was about 90deg clockwise from the position it shows. The rest of the leads corresponded to the order shown on the diagram and I tried to get the under and over cables to match, but with the rotation of the distributor it didnt look the same. The cables on mine are also longer so there is some slack looping out towards the front of the car, especially cables from the drivers side bank .

I will have another look tomorrow though.

What I am not sure about is the 3-4 ribbed cable conduits snaking about above the distributor, connected to the coil at one end and then looping around under the top coolant pipe. There seem to be a long block (connectors?) there under electrical tape.

Is anything there that could have been dislodged in that lot? I dont really want to unpeel all of those cables to check it but that block under the tape, what is it?

jazzdude

Original Poster:

900 posts

152 months

Sunday 29th November 2015
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Incredible.... 2 & 4 were the wrong way round!!!

Can't believe it to be honest, you would have thought it would have made loud noises, backfired but it was just a little lumpy, so I spent the afternoon checking for tightness in connections and not the order of the leads as I did them one at a time. Somehow they switched.

Thanks for that smile

jazzdude

Original Poster:

900 posts

152 months

Sunday 29th November 2015
quotequote all
Steve_D said:
Now you have the fix it is still worth observing for others that cross firing can happen with leads touching each other and in this case 5&7 are the worst case as they are so close in firing order.

Steve
I will check that but with the leads being a bit long (Lucas original) they don't go as directly as the diagram but curve upwards, but I'll move the distributor connections around so nothing touches.