1989 XJS...engine lugging and won't turn over...battery new

This vehicle has been towed 3x. Have it home now. Battery is new. Lugs and will not catch. Low lug with no chance of catching…time sensitive as my insurance re ups on 15 July. My mechanic had a stroke thus benched. I thought by the way it lugged, it wouldn’t catch. If it spun faster it might. I freed up the idle speed screw on the left rear quadrant…I got it so it would screw and unscrew properly…I also change as maintenance the fuel filter without difficulty. The lugging is questionable as no engine would catch at that low velocity. Any ideas would be helpful as time is dwindling and I don’t want to re up a vehicle that is not running.

Which I interpret as “starter cranks engine very slowly”.

Check/clean/tighten negative battery cable where it attaches to the body.
Check/clean/tighten main engine ground strap (probably at LH side motor mount).
Check/clean/tighten the “+” battery junction posts on the firewall.

Post back with any changes


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Doug, I took your advise and chequed all three…nothing…the engine lugs when the key is turned. Just for the heck of it…where is the crank sensor? I have tried to find it but with no luck.
If you have any other ideas please advise. If the engine was turning faster it might catch, the way it is, it doesn’t have a chance.

Richard, even if the battery is new it could be a case of the battery being the culprit, especially if you have done what Doug suggested:

  1. Is not the correct amount of Cold Cranking Amps (CCA)

  2. Alternator is not keeping it fully charged

  3. Battery is new and is rated at enough CCA but the battery itself is just a bit of a dud.

I would take the battery to a parts store and have it load tested.

The starter could also be simply worn out.
And there’s a saying among mechanics, “new doesn’t necessarily mean good.”


Is there a way the starter’s terminals are dirty? I have 9 days to make it or brake it, and I love this vehicle. I have had it for 5 years and made it mine…I would hate to lose it.

  1. 585 CCA, load tested and is good. I did this this afternoon at NAPA.
  2. My mechanic claims the alternator is good.
  3. Refer to number 1.
    Just grumbles and that’s it.

Time to remove the starter and have that bench tested methinks.


Does battery have a good 12.4V or so before starting?

If so, then sounds like your starter is failing. If it’s original 35 years old, then it probably needs replacing.

Has the starter been changed?

I have experience of a starter that would only just turn the engine over being restored to as new performance simply by stripping and cleaning it. The issue was corrosion in the mixed metal body was causing a poor Gnd.

Given the option I would stick with the original starter unless proven to be worn out. They don’t make 'em like they used to.

To begin with, I would try with another battery.
If no change I would remove the plugs and see what happens, to be sure there is no other mechanical failure.
Next would be removal of the starter.

Have you tried starter fluid to see if it starts with that?

If it starts with starter fluid and continues to run, fuel and ignition is atleast good enough to run.

Rather than just making sure the connections are tight, I would remove the battery terminal cables and clean them with a wire brush, then undo the negative ground cable from the other end of the battery, do the same, and then do the same with the starter connections. Use a wire brush and electrical contact cleaner. Then try your start and report. SD Faircloth

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See what battery voltage is. You want 12.2V to 12.4V.

Then simply test voltage at starter positive post and make sure it’s the same.

In addition to the above, use alligator test lead clips, clip one test lead to starter positive post and one to engine ground, read the voltage as you turn the key on and while cranking.

Each poor connection will induce a voltage drop, so read the voltage under full stater load current.

If the voltage doesn’t drop way down, it would be the starter.

If the voltage drops way down, it likely isn’t the starter. It would likely be the conductor circuit to the starter.

Disconnect the alligator test clip from the starter and connect it to the battery post on the firewall/bulkhead, then retest.

If no major voltage drop, it’s the cable to the starter and/or its connections.

If still have a major voltage drop, that means go to what @SD_Faircloth said, cleaning everything.

Yeah, chequed yesterday at Auto Zone…585 CCA/ 13.2v.

Richard I’m not sure what the time frame references are all about, not my business or intent to pry, but what I can tell you about these cars is take a methodical approach time is not always in your favour when trying to track down issues and/or potential problems. It’s part of the journey. I know they can be frustrating but I think the fellow members on this forum have suggested half a dozen good starting points of where you should be looking.
Just as an example I’m sure I’ve started working on or trying to sort out issues which I thought would take me 1 hour , three days later, I’m still scratching my head with the only thing I have to show for it , skinned knuckles!
Be methodical ,take your time , you will get this across the finish line.

I’ll second that !

The right frame of mind is everything with these cars.

Slow and steady wins the race with these cars. If you become hurried or aggravated the car somehow knows…and gleefully pushes back with twice as much gusto !

And always remember that there are no engineering flaws in these cars. Anything that appears to be an engineering flaw is, in reality, “an interesting design feature”. :slight_smile:



Even to the point of … I’m tired of digging through my wrenches to find what I’m looking for (I have SAE and Metric separated in my wrench drawer of my tool box) , so I’m now in the process of building more drawers in the garage so I can find what I want easier.

This wall will have drawers where the metal bins are now. I’ve just finished (except drawer fronts, they will be added when all drawers are complete so I can align the fronts with each other) a 4 drawer stack where the right stack of metal bins is in the photo.

First drawer stack is ready for loading.

All this stuff will now take up half as much space as it did.

The space is 8 ft wide, which will leave 4 ft for drawers for wrenches, etc., (area outlined in red).

I have the skinned knuckles but nothing to prove for it. I am chequeing the connections to everything I think is related. The starter was changed a few years ago and if I could get to it would cheque the connections. Each time I try to start it, I lose battery voltage with reallY no way to replace the loss. I am in a tight space outdoors with no way to get under the vehicle. At my age 77, I have seen to many accidents with jacks and the like thus that’s out. Is there a way I can tap the starter/solenoid from the engine compartment to see if possibly that makes a difference? Or for that matter, ny known relays or switches to clean. My insurance comes up on 15 July and I would like to keep it instated. Thanks.