Hi everyone,

I recently had a no start/no crank condition, and since I took so many pictures, I thought I'd try my hand at a "how-to" thread.

First, the symptoms; I had a slow crank/poor charge situation several months ago, plus a no crank scenario a few days ago, and the failure point was the same.

So on Thursday, the car had been cranking slowly after having a cylinder wash episode. Getting the car started after the wash was hard on the starter as it always is. I suspected a dying starter, or a bad false bulkhead connector and had full intentions of fixing it, but the car beat me to it.

It cranked slowly but started. I drove 50 km to the airport and stopped to see a friend. The car ran fine, with no warning lights at all. On my start attempt, nothing happened, not even a click from the starter. Headlights were fine, jumping with booster cables had no effect. The battery cables and fuses forward of the spare tire were fine. The false bulkhead connector (FBC) was in good condition.

Jump forward 2 days. My son picked me up at the airport with jumper cables, tools, and my multimeter. Measuring from the false bulkhead connector to the shock tower bolts got 12 volts, and 11.9 when the key was turned.

Measuring from the connector to the throttle body ( the only easily accessible engine metallic part) read 2.3 volts. Clearly the engine was not grounded to the frame, and of course 2 volts wasn't going to turn the starter.


Knowing the problem, and not wanting to crawl around in a parking lot, I used the jumper cables to connect the engine to the frame by clamping onto the transmission bell housing and the shock tower bolts. She started just fine, and I tucked the cables under the hood and drove home like that.

The plastic cover over the engine fuses and throttle body were removed to get access to the transmission.

The next day I checked the grounding strap, and it was still tight from last time, with no signs of corrosion under the lugs. However it was clearly bad and the cable itself was corroded, although not badly.

I installed a new cable, using the lower starter mounting bolt for one end, and the factory point for the frame. The starter cranks her like new, with no loss of voltage. The alternator is now charging the battery nicely, seen on the meter here.


The battery as you can see is much smaller than original, yet it spins the engine over quickly, when the cables are all healthy. It had a red dot in the window, showing it was discharged, but turned green after a while on the charger.

Moral of the story- if your XJ8 won't start, try the jumper cable idea, it'll get you home. Also you can use the same idea to troubleshoot a charging issue without a meter.

 

Nice job on the "how to" thread. I wa just wondering is your smaller battery vented thru the the rubber hose to below the car?

 

No, it's not vented at all.

 

Invest in the correct battery which is connects to the 1/4" black rubber hose that is there to vent the battery to the atmosphere. You don't want the poisonous and potentially explosive fumes building up in the trunk

 

Thta's an idea, yet my 911s both had trunk mounted batteries without vents, so I'll probably stick with this one until it dies.

 

My 2000 XJ8 VDP had this issue. For me, replacing the ground strap was not the only issue.

1. Fully charge a good battery
2. Grind the contact points at the transmission and frame where the strap bolts to until you see fresh metal
3. Clean the bolts that attache the ground strap
4. Replace the strap (I chose to spray rubberized undercoating to the freshly cleaned contact points)
5. Clean starter contacts, bolts, nuts, and electrical fittings
6. Clean contact points on altanator, and electrical fittings
7. Clean and lube false bulkhead

If you have to remove the alternator for any reason remove the oil filter, hex thread that the oil filter attaches to, and the alternator bracket.

All is good... for now