African Muscle Cars - Forum

I had similar issues with an XR3 back in the nineties. Check the connectors at the back of the alternator. Don't use individual lugs, get the proper connector. It solved all the issues.

I dont think your battery is being drained while driving. 14.2 volts is plenty. It seems that way because after you have warmed up the engine it needs more battery amps to crank it. What is the amp/hour rating of your battery.I have found that the 657 works well. It is recommended for diesel engines so your chevy should be no problem. Also the earth cable needs to go from the battery directly onto the engine block. I know its a mission but it works way better.

P.S. If you are using one of those new fong kong starters then ignore everything ive just said because thats the problem. Get a decent gear reduction starter.

Any chance that your ignition timing has perhaps adjusted??
Once you have trouble shot all the electrical woes (if any) and the issue persists then it might just be worth a shot to recheck your timing.

Just my .02£ worth of opinion.

Cheers.......Robbie.

Thank you for the input, guys. The Jeep went in today for a 3-4" lift . When it returns, I will change the earth to the engine and see if it works. As for the timing, I recently had it set, so I doubt it......But who knows? Gremlins can be anywhere!

Measure the voltage at the starter.

If for example, it is 13,5V at the battery, it must be 13,5V at the big terminal at the starter.
If it does not give 13,5V at the starter, I suspect that you have a bad connection along the way.
Resistance between the center of the + terminal and the battery clamp should not be more than 0,2 Ohm
Resistance between the battery cable and chassis earth (with battery disconnected) should be infinity. (open circuit)
Cable resistance from battery clamp (measure from the clamp to the lug at the starter end) to starter terminal should be about 0,2 Ohm

When you crank it, voltage must not drop below 12V at the starter.

If it does drop below 12 V while cranking, chances are that the battery is on the way out.

is there an electrical fan on the radiator?If so check voltage when fan comes on.That was my problem...is when that fan came on

Thank you for the input, jmvv. I will sure do the tests.

Sapphire, you might have cracked it...... I have a radiator fan that comes on as soon as I turn the isolator switch to give power to the system. That's even before I put the key in the ignition. It makes sense. I will put a seperate switch in for the fan and see if it improves. Thank you all. I can't wait for the Jeep to return so I can get the thing sorted once and for all.

The voltage when the car is off is 12.6V. When I crank the engine, the voltage drops to 9.6V which tells me the battery is shot. What bothers me though is that a rapid charge with a battery charger for about 15minutes, charges the battery enough for it to start, but when driving for about 30mins (with the altenator charging at 14.2V), the battery is not charged enough for 2 starts.

I'm taking a long shot here, but are there any mechanical issues on these V8's that will cause more resistance to the starter once the engine reached operating temperature?

If the exhaust pipe comes close to the starter it will most definitely cause a starting issue due to the extreme heat,to the point were it wont even turn over! A heat shield or exhaust wrap should help! If all else fails just buy a quality new reduction starter,they really work well!