V8 - lumenition to powerspark distributor wiring help please

pardonthewait wrote,...
There should be an earth strap from the block to the bodywork, right?
Click to expand...

The strap is on the left hand side of the engine, just near the engine mount.

I can certainly appreciate how incredibly frustrating this would be!!

Ron.
 
It's incredibly frustrating! I'm just clinging to the idea that eventually we have to track down the issue!

I read another thread just earlier that mentioned really silly things with the wiring causing a car to cut out, and it made me realise that all the toot hanging down behind my dashboard (not my doing) should probably be a higher priority than I'd made it so far. There are various bullet connectors and so on hanging behind the dash above both glove boxes (and various bits of the dashboard instruments don't work), it's quite a state. I will get to work tomorrow isolating them at least. I mean obviously they're supposed to have stuff attached to them and I will see to that but for now I want to make sure nothing is shorting and causing an issue.

I'll also take a look at the earth strap. Left hand side of the engine as in passenger side, or my left looking in the bonnet? Just in case it's actually absent I want to know where it should be!

Cheers

Rob
 
Hi Rob,

The convention is that the right hand side is the side on the right side when seated in the driver's seat. Regardless of whether the vehicle is right or left hand drive, the right side is always unchanged.

There are numerous unconnected wires all around the Rover, near the coil, fuse box, instruments just to name but a few.

Another possibility is the ignition switch, which is located at the rear of the barrel. What I have experienced is that the engine will turn on the starter, but the moment the engine fires, it cuts out. The switch can be removed, cleaned and refitted or replaced. but it is very fiddly. To remove the switch, you'll need to remove the centre console and then work in from behind.

Just a thought.

Ron.
 
Progress maybe. The electrician has been round tonight - we now have a spark but it's not enough to turn the engine over.

The supply to all the lives drops to 9-10v when cranking. We've ruled out it being ballasted, because all the lives seem to do it.

He reckons poor earthing is a very likely cause. I can't actually see the earth strap you mention looking into the engine from the bonnet, but either way, the earth strap on the battery is in pretty bad shape so I'm going to grab a replacement for that and run some inside the bay as well.

It was actually making a real effort to start tonight so I think we're getting somewhere.
 
Hi rob
This must be driving you mad.
Thought of a couple of items that can give this fault and have come across.
1 apart from the 2 earth straps which i know your looking at.
2 main battery cable/starter motor connector post under front drivers side on floor,these over time work loose and get hot/melt and in some cases short out main battery cable.
3 Get battery tested correctly /may be starting to fail.
4 Starter motor may be drawing too much current leaving not enough current to coil.
5 Main positive terminal where wire crimps in becomes loose giving high resistance.
Hope this is some help.
Clive.
 
clive P62 said:
Hi rob
This must be driving you mad.
Thought of a couple of items that can give this fault and have come across.
1 apart from the 2 earth straps which i know your looking at.
2 main battery cable/starter motor connector post under front drivers side on floor,these over time work loose and get hot/melt and in some cases short out main battery cable.
3 Get battery tested correctly /may be starting to fail.
4 Starter motor may be drawing too much current leaving not enough current to coil.
5 Main positive terminal where wire crimps in becomes loose giving high resistance.
Hope this is some help.
Clive.
Click to expand...

Sorry to be such a dunce but can you clarify some of these for me? I'd like to take a look at them all through these evenings as the electrician should be available at the weekend - so as much as I can do on my own I'd like to but it does mean working outside and in the dark so I always try to go in with as much knowledge as I can!

1) Is this the guy I'm looking for - or replacing - on the engine? A friend of mine's bringing me home some battery cable, ends, battery terminal and the big crimper to put it all together so I can make up whatever ones I need. Would it hurt to bang another one elsewhere on the engine as well?
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2) I'm unsure what you mean by under front drivers side on floor - in the engine bay at the bottom? Do I just chase it from the starter motor til I find it? Or is it under/in the car?

3) Battery should be ok, it's very new. We also had it running from a big booster pack tonight, and then from the electrician's car, so I don't think power from the battery is the issue.

4) How would I check this?

5) Main positive terminal - I'm unsure what you mean by this - the positive terminal on the battery or elsewhere?

Sorry again to be such a nitwit - I've always been willing to get stuck in but before this car it's gone about as far as replacing brake pads, fitting exhausts, springs, coilovers, stereo equipment and so on. This car being so badly behaved has very much thrown me in at the deep end and I'm learning loads but I'm way out of my depth :D

I do always try and find the answers in my workshop manual as well but it's a bit vague and missing a fair bit of information. I must try and get hold of the Rover one, mine is an Autopress one.

And yes it does help! Really appreciate everyone's patience and sympathy!
 
The engine earth strap is there but it's completely caked in filth and oil so it's hard to tell. Will replace and clean up both ends before putting new one on.

The starter motor bit I think I've found and same story, completely caked so difficult to see really. I will have to attack that one in the daylight I think. The car leaks some oil and it appears to be coming from the top of the sump so I guess I will have to get that off and put a new gasket on there if there is one or seal it up some other way. While I do that I will have to have a thorough clean because it's disgusting under there.

I took some pictures of both bits but it's raining and dark and I was upside down so probably of little use.
 
Hi rob
Chassis /engine earth lead looks correct on photo,1 end bolts to engine block normaly with a 5/8 spanner size bolt which sometimes shares its position with fuel feed metal pipe to original pump.Other end bolts to engine mount position on chassis with a 1/4 inch hole already present on side of this mount.
2 If you lift up carpet under drivers pedals you will see battery cable connecting to this post.On the underside of floor small lead connects to starter motor as main feed.The 2 cables are kept from shorting to floor by nylon insulator.
4 some electricans have a clip on amp meter to fit to starter motor main cable,long time since i tested this but i think current draw was approx 250 amps/or remove starter and check brushes and general condition.
5 Main terminal itself on battery where wire crimps into terminal/this is quite rear but have seen one that was loose.You can buy new terminals so you can cut off old one strip off some insulation and fit cable to new terminal with screws instead or crimping.
Hope this is a bit clearer it does sound like you do have a supply/earth problem.
clive.
 
Engine now has two earth straps, a new one in the original location (rubbed down to metal at both connections), and one from a manifold bolt to where the coil earths. Battery negative strap is new.

Alternator for this test was completely unplugged.

Starter motor connections seem good, the main one at the live that goes through the floor of the car was good and looks quite fresh on both sides. I degreased and sprayed down that area of the car as it is totally filthy, checked all connections on starter motor which looked good to me, old, and the wires a bit brittle, but all connected. One connection came off quite easily but plugged back on and seemed sound. Degreased and sprayed down, then drowned in contact cleaner. This was two days ago.

Left plugs out for two days in case engine was flooded (probably was).

I get a spark from coil to distributor (so says my spark plug tester) and tried two plugs on right side (hard to see because I'm working on my own) but I saw the light go for one of those, tried one on left side and the light lit for that one too. Still no start!

One misfire, that's it. Battery is losing its power quite quickly - at first there was a fair bit of shaking and chugging from engine, but after a bit of cranking it goes much quieter.

Really losing my patience now! Completely clueless as to what to do next. I really need to get the car jacked up but I jacked it up from the U-shaped cross member the other night and put a block under one wheel, but can't really see anywhere I'd be confident to put at axle stand.

I'm just really frustrated and have no idea what to do next and right this minute wish I'd never bought it!

Fuel? I just find it so hard to believe that the fuel and the ignition have simultaneously failed!
 
To the best of my knowledge and abilities which is not much, yes.

I turned the engine so that the TDC marker was where the white arrow marker is. Then I fiddled with the oil pump spindle until the distributor when completely home was oriented so the rotor arm was pointing at where my manual says #1 cylinder should be. Then, clockwise, I plugged in the leads in the right order.

So if I've done that right then yes, if not no!

I have a timing light but is that any use to me at this point? Will it "work" if the engine is just turning over on the starter?
 
The most common mistake (I know i've done it on multiple occasions) is to have the leads 180 degrees out. if it was me (and i'm no expert) i'd try just swapping them over 180, and if that doesnt work just move all the leads round by one till it sparks up. I think it will. This is timing if you arent sure of the current state....

In my experience if there is a spark the rv8 is pretty easy to get running. Some other engines are a pig comparitively...

Rich
 
I think I now understand about 180 degrees out - I didn't realise how it could be but now I think I understand better - the distributor turns once for every two times the crank turns, is that right?

Either way I will do that first thing tomorrow. Is the correct way to do this to leave the cap as is, and turn the distributor rotor 180, or can I rearrange the leads on the cap? Or will either work?

Thanks,

Rob
 
Easiest is to move the leads. When it sounds like it's going to fire get some one to turn the dizzy while you operate the ignition :)
 
I moved them all around by 180º and no change - moved them round one more and still no change. Do I just keep moving them around by one until something happens?
 
Took all the plugs out, took all the leads off, labelled them all up to be sure. Found TDC with a stick down the plug hole and put it all back together.

It really wants to fire up, it's definitely trying, but it feels like we can't rotate the distributor enough to get it to where it wants to be.

I feel like possibly I need to get it so that the rotor arm and plugs are all like... half of a position around, if that makes sense. So that I can retard or advance it further. It's definitely trying hard to start but I can't quite get there.

However it's absolutely the closest I've got so far. Calling it a night for today as it is absolutely freezing out there at the moment and about to get dark. Might have another go tomorrow.

Thanks for continued help, I finally feel like I'm getting somewhere.
 
Well that sounds like progress. If you move the leads round by one it's going to run by the sound of it :)
 
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