My car came with the larger alternator.

Here is a good writeup on how someone else did it. I'm sure others on this forum have done it and might chime in on the lowdown.

Replacing and Relocating the Alternator with a CS-130

 

I took the 115A unit to an alternator shop and asked them to install the v belt pulley and fan. The gentleman looked at the existing pulley on the original alternator, rummaged around for a match and pressed it on. $12.

As for the mounting bolt, you'll need a 10mm bolt. The air pump has one if you have removed that you can use it. The mounting bracket will need to be drilled out to match. A drill press would come in handy here.

 

I purchased the 100amp Land Rover Defender alternator described in Kirby Palms book. Part #13697 Lister. Supposedly all i need to do is swap the pulley, and figure out which post the wires connect to! I will also run the extra 6 ga power wire and add a dedicated ground strap as well. I’ll update when it’s all installed.

 

UPDATE:

I installed the new Land Rover alternator. Contrary to the instructions in Kirby Palms book, it is not exactly a direct replacement. The bolts are all the same, so it does not require modification to the mounts. But it does require modification to the pulley. The shaft is larger and not keyed. Luckily i have a lathe at my shop.
After install, she seemed to purr like a kittten. Measured 14 V at the coil and 14.34 V at the battery. Went for a ride down the road..... and had worse hesitation than i had before! I thought that maybe with the proper voltage, the two .6 ohm coils were not enough as stated by Grant Francis. So i put my “new” single .6 ohm replacement coil back in....
she wouldnt rev above 1500 with it in.
i will attach two videos. Both are with the original duel coils.
The first is my foot steady at 3500 (thats what i was shooting for) while the car was in park.

The second was pedal to the floor from stop while driving.

I cant get it on video because of the hertz rate of video, but i can see the spark become erratic with an induction light on one of the plug wires? Im still a proponent of my issues being related to the spark or spark signal..
thoughts!?

 

Are the plugs and leads new? is the dizzy cap and rotor new? Have you tried a new/known good amplifier?
Also, what state is the star wheel and pickup in, within the dizzy? And the lead from the dizzy to the amplifier?
Finally, it is just possible that a bad zener diode in the ECU can do this. Worth swapping in a known good one.

 

All plus and leads are brand new. Cap and rotor are brand new. Amplifier is the second brand new one (original tested bad, both new ones tested good at the parts store) pickup and star wheel look good. Pickup tests at 3.6 Kohm, gapped at .008. Wiring from dizzy to amplifier looks good.
Dont know about the zener diode.
Its hard to tell with a timing light whether there is a stumble in the spark coming directly out of the coil? I can definately see the stumble with the timing light out at any given plug wire though.

 

I know you have tried various coils etc. But a known good one swapped in has to be the first thing to check. Also, take a look inside the dizzy, to check all is well, AND that you were sent the correct rotor arm.


Also swapping in a known good ECU is also really worth doing. There is some gizmo in it, which if it fails, produces poor spark at higher revs. happened to me with a rebuilt one I bought. The guy who rebuilt it, VERY competent guy, said a zenor diode (whatever that does) in the ECU had given up.


Greg

 

OK.

Thinking for a while on this.

I agree that the visual of the "flash" from the coil is hard to pick, and since you can clearly see it at any plug lead, my thoughts are, in NO particular order:

Greg's suggestion of the Zenor tracking to earth is valid. It can be dis-connected from the system, BUT, if a spark plug decides to not spark, the back feed WILL fry the module, so your call, but I have done it, and got away with it.

The gap at 0.008" is a tad close for what I use, but I think??? you have tried 0.014" without success.

It sounds like a triggering issue, and that trigger is the module.

Since the spark is a stumble "out of the cap" at the moment, the rotor MAY be earthing the HT current via the distributor shaft, as I mentioned a while back, as quality these days, no matter the supplier, is borderline crap. I had issues with mine with rotor height, so the arc at the cap posts was in the correct spot, I fitted a fibre washer (duly filed and messed with so it fit inside the rotor), and that gave me the height I wanted, and the strange running, which I put to rotor height went away????, whoopee, but I was not convinced it was that simple, and I removed the washer, ran it again as it was, and crap. This time I removed the cap gasket, and this gave the same arc placement as with the washer, crap running, Bugga. Back inside, and the washer fitted, and the gasket refitted, and its still that way today. Scientific, HELL NO, but that washer insulated the underside of the rotor "hole", and that is ALL I can say on the matter.

Rotor leakage is not common, but it does happen, and hard to find, as we all know the saying "its New, what else can it be".

HOWEVER

If the spark stumble FROM the coil can be verified, then there is other items at play, and the only thing that triggers the coil is the module, via the pick up pulse.

JUST FOR GIGGLES

Take your DVM, Black lead to a GOOD known body earth, Red lead attached to the distributor cast body, and the volts set at DC, say abut 20ish. Run the engine, get the stumble, see what the DVM reads. If you have anything above 1volt, you have an engine earth issue. My PreHE had 7volts, and once I simply connected a jumper battery cable from the engine to the body, it dropped to 0.8v, and surprise, the engine settled down. Added a couple of extra earth straps, and left it alone, and that subject is a Pet with me now when diagnosing engine running issues.

It even made a difference to my 2000 S Type V6, that had a strange misfire, and drove more nuts than normal. A simple earth strap from the Inlet manifold to the nearby chassis bolt, and all sweet.

 

Grant
I meant a zener in the actual ECU (where I was told there is also one). I assume the one in the amp is OK as it is a new one. But I totally agree about looking in the dizzy etc.
Greg

 

Maybe i was unclear, the gm hei control module in the AB14 is new. The pressed in zener in there is original amd still currently connected. I have yet to run it in the dark and look for any stray spark. I will be doing that. Everything in the dizzy appeared fine, i believe thete are pics earlier in the post. I will also be trying the insulating washer under the rotor and checking voltage to the dizzy body.
Also, is it normal that when i start the engine, it will sit around 450 rpm for about a minute, then jump yo 1000 and settle in around 800 all on its own?

 

FWIW, I had a funny acting up amplifier, in my case intermittent start/no start. So I fitted a new HEI module to it, then another, and it still was not reliable. In the end I forked out for an actual new entire unit, and all problems disappeared.
So I suggest you get a known working entire amplifier and swap it in. If it makes it go OK, fork out for a new entire unit.

 

Ok here we go.....

Disconnected zener diode, the car started but would not rev above 1500 rpm. I noticed the wire to the zener was extremely brittle. So i replaced it from the zener to the ‘white blob’ and reconnected the zener.
Upon reassembly, i put in the second newest hei module from Oreilly Auto Parts.
When started it would rev, with heaitation, to around 3500 rpm.
I dissassembled again and replaced the hei module with the echlin TP45 module.
This time it started, and would rev, with heaitation, to around 6000 rpm.

At this point, and with this setup, i put the timing light on the coil to dizzy lead and definately can see a hesitation coming out of the COIL. So for now, i have eliminated the dizzy as a possible suspect and all my concern are with the AB14 amplifier.
i have purchased a used, garaunteed (60 day return) working AB14 unit. I will update when it arrives.

intersting note:
when the zener was disconnected, the car started and adjusted to idle almost immediately, with the zener connected however, it takes almost 45 sec to adjust. See the attached video where my foot never touches the gas (need to watch to the 50sec mark). Is this a normal time for the idle to adjust?

 

Forgot to mention, there was also no voltage present when hesitation occurred between ground and dizzy case.

 

Explain a bit more, please. Where exactly were you placing the meter probes to do this?
Greg

 

The idle should settle instantly. The reaction you are seeing is NOT normal in any I have owned or looked after.

I still think the Zener is "leaking", but that is a best guess, as I have not had one fail, only based on what I know "would" happen with them.

This I found years ago, might help, and go into your own archives.

 

The most common failure mode for a zener is short circuit, if they do fail open circuit they tend to crack and this is very noticeable.

The zener will be there for protection and clamp the voltage at the zener voltage of the diode, this prevents voltage spikes from getting to the ECU. It will work without it. The resistors are there for current limiting do not run without them.

If the car runs without the diode then I would replace it. It'll have a number on it and you should be able to find a suitable substitute.

 

this was a test Grant Francis suggested to see if i had a valtage leak to ground possibly through the plastic rotor of the dizzy. So the test was with the red lead of the DVM to the aluminum case of the dizzy and the black to a known good ground. The test showed no voltage, but i have determined the spark miss to be before the dizzy anyway.

 

Hopefully the new AB14 will fix this. Since the car adjusted idle immediately after i removed the zener, im hopeful i have found my problem somewhere within the amp.

 

That was the problem. The car would idle without the zener, but would not rev above 1500 rpm.

 

OK, sorry I forgot Grant's earlier test; but as he said, a known good body ground I hope?
looks like you are closing in on the problem. The amp is looking more and more like the culprit. I admire your patient way of testing and working through the problem.
Greg