Starter motor loses power when warm

Sorry everybody for not getting back to my starter motor problem. The car is currently up on blocks but I wanted to try to figure out what might be able to do to stop this issue, when I get it running again. I've owned the car since 1972 but have only driven it 11,000 miles since then.... none in the last 10 years. It's all original with 37,000 miles but the rubber is hard as a rock and it needs paint, and whatever else from just getting old. I plan to sell it when I'm done and just got all the rubber from SNGBarrett. When I get it up and going, I'll check out all of your recommendations. Many thanks for your great thoughts on this! Here's a pic of my cat.

Pull the starter and have it rebuilt, or, install a newer-model Jaguar starter that will retro-fit perfectly.

Patrick

There are a lot of problems being discussed on this forum. However, using one quart
of oil per tank of gas is a MASSIVE problem. I assume you had your engine repaired
because of previous oil/performance problems. Did your mechanic also check/overhaul
the head. valves and valve guides? If the valves and guides have excessive ware, since they operate in a pool of overhead oil, the intake stroke vaccuum will suck oil into the combustion chamber. This is a very sneakey type of excess oil consumption and is
barely detectable in daylight. However, at night, with a vehicle in your rear view mirrow,
you can probably see a small white cloud of smoke after deceleration and acceleration.
Another problem may be if you are using synthetic oil during the break in, it might take
8000 miles. Dale Conrad - Carolina Jags.

There are a lot of problems being discussed on this forum. However, using one quart
of oil per tank of gas is a MASSIVE problem. I assume you had your engine repaired
because of previous oil/performance problems. Did your mechanic also check/overhaul
the head. valves and valve guides? If the valves and guides have excessive ware, since they operate in a pool of overhead oil, the intake stroke vaccuum will suck oil into the combustion chamber. This is a very sneakey type of excess oil consumption and is
barely detectable in daylight. However, at night, with a vehicle in your rear view mirrow,
you can probably see a small white cloud of smoke after deceleration and acceleration.
Another problem may be if you are using synthetic oil during the break in, it might take
8000 miles. Dale Conrad - Carolina Jags.

I agree with William that this thread is getting a little confusing. Especially to a senior citizen such as I / me. :-) Tony and Jeffery may have two totally different situations.

There is a piece of test equipment available which I find very helpful in troubleshooting starter and generator / alternator but the test results can be a bit confusing or misleading. That equipment is an inductive ammeter which can measure the current flow, not voltage, when placed against the wire / cable. No electrical connection is necessary however the measurements must not be taken in the immediate vicinity of the starter / generator or the reading may be incorrect due to the magnetic field surrounding those units.

One model of meter has two ranges, one for generator / alternator and the other for starters.

If the starter is turning the engine slowly and the starter current draw/flow is high then it's probably due to heavy load from the engine or a faulty starter. If the current is low but the battery voltage is normal then it may be a poor connection, cable or faulty starter.

That doesn't narrow it down too much but it's a beginning.

Thanks Thomas and William, I'll check the ground strap. When I jump start the car I go battery to battery and I rely on the gauge for the water temperature. THe car runs great except for the starting problem when hot. I was wondering if it was a weak starter

This is getting confusing, Tony began the hard starting thread but we haven't heard from him since the first response! Jeffery came in with his issue, initially seemingly a similiar problem but it quickly became more complicated. His excessive oil consumption caused by these rings is certainly a cause for serious concern, i'd be surprised if the plugs weren't fouled already.

Tony, the chromoly rings will take longer to seat because of their hardness. A lack of friction would make your engine spin over faster not slower. The rings are not your starting problem. Check the ground strap between the chassis & engine. Check the ground from the battery to the chassis. When you jump start it from another car, do you attach the jumper cables to the battery or the engine? If you are attaching to the battery, that should eliminate a cable or ground problem. If you attach to the engine itself & it starts better, then you have a cable or contact problem. Advanced timeing WILL make it start harder when hot. Have you checked the actual engine tempeture or are you relying on the gauge?

Firstly, 8000 miles is ridiculous, this appears to be a catch all to fend off complaints, I feel like contacting the EPA. Who rebuilt the engine? Most restored cars would likely take years to amass these many miles. If it is using this much oil via the rings then it has to be losing a significant amount of vacuum. Vacuum is key to starting, with no vacuum a carburretor car cannot run! The oil "seal" between the bore and the rings is essential to quickly allow a vacuum as was evidenced by the Nikasil issue on the 4.0 XJ engine, in that case, the oil drained off because of the glass like surface of the bores, in your case, as the oil gets hotter and thereby thinner it just leaks down past the rings, meaning it can lose that "seal" quickly. The faster the engine turns the quicker the "seal" is established.

It turns over at about the same speed as normal, but sometimes when I jump it from a running vehicle it spins faster and starts right up. I had the battery checked and it puts out the correct amps. The pistons are new with cro-moly rings, which is another problem because the engine uses about a quart of oil every two tanks of gas. They say it takes cro- moly rings about 8,000 miles to seat properly. Seems high to me what are your thoughts.

Jeffery, does it turn at all, if so it is a piston/overheating problem, if not it is a starter/connection problem. It is worth checking the timing anyway but usually if it were so far advanced it would be noticeable/pinging on acceleration.

I have a similar problem with my 1965 E series 2 , the starter seems to work properly but if the engine temperature is above 70 degrees C. when I turn the engine off, I have to wait 20 minutes for it to start. The car also runs better when it is cold outside, again when the engine temp get above 70 degrees the engine misses at higher RPM's. My mechanic thinks we should change the timing a bit to see if that will fix the problem. Very frustrating, would like some other ideas. Thanks Jeff Sims

This is typical of the expansion of the pistons when an engine gets very hot, is it?