C5 mk 1 starting problem

[white exec]

Simple and cheap things first, though!
Overnight charge the battery, and see how it starts then.
If AOK, then you almost certainly don't have a starter motor problem.

Believe me, properly working glowplugs are essential to a prompt start, on anything other than a warmed-up engine.

Cautions about allowing electronics to go to sleep are in order. If you're clever, it's possible to connect your multimeter ammeter (set it 2 amp range) to run from the battery + post to the battery + clamp terminal BEFORE you slacken off and lift the clamp connector from the battery post, and keep the meter connection made. That way, you get to measure the current flowing out of the battery, without disconnecting the car's electronics. Takes a bit of care to do, but possible . . . just don't break the circuit, or it will be the same as doing a normal battery disconnection.

When doing this, make sure all doors are closed, lights, radio etc are off, so you won't be misled or measuring a high current (unless there is something unhelpful still left on!) Even better, wait 30 minutes before doing the test, so the car's electronics can go to sleep.

[BX]

Unfortunately things are not quite that simple. As a starter motor looses efficency it draws ever more current to do its job. A very poor starter can be masked by a good battery with battery lifespan suffering as a result. With a starter at peak efficiency less than 150 amps is often drawn during a cold start. With a poor starter the current drawn can reach up 500 amps at times.
On the other hand worn brushes making poor contact on the commutator can draw low current and turn the engine slowly.
First and easiest check is to monitor battery voltage whilst starting. If the voltage remains at 10V or over and the engine turns slowly check the voltage between the battery terminal on the solenoid and the engine block. It should be within 0.5V of the battery terminal voltage. If it is suspect the starter. If there is a much higher drop check all leads and connections.
If the batteru oltage drops below 10V then you need to measure the current. Less than 200A suspect the battery. More than 350A definitely the starter.
The KW ratings listed in an earlier post are maximum. The power used/produced depends on many factors. Fitting a higher power starter can sometimes reduce current drawn. The relationships are too complex to go into here. However there are probably online articles that describe the behaviour of permanent magnet brush type dc motors. It should be possible to borrow books on the topic from a local library if anyone really wants to immerse themselves.
A regards glow plugs I do not believe they are relevant in this case but am prepared to be proven wrong.

[hirsty]

Well it definitely isn't glow plugs as they are 1 week old Beru's. The battery is brand new. Everything is fine after first start, so I don't think poor connections are a problem. I will have a new starter fitted next week and see how it goes from there.

hirsty

[Hell Razor5543]

I recently got a recon starter motor from GSF, for around £120. It was a Bosch, and slightly longer than the original. I had to make up a short cable, as the original used a round connector onto a threaded rod, while the Bosch used a spade connector. I got back about £50 for the old motor in the packaging provided (so that it could be reconditioned). Spins so fast (compared to the old one) that I thought the CAR would turn over, as well as the engine! There is a minimum RPM the engine has to achieve during the starter cycle before the injectors will receive fuel.

[Peter.N.]

If they are the same as the XM starters you can take the gearbox off the front and fill it with fresh grease, that gives them a new lease of life.

Peter

[hirsty]

I had to jump start this week and noticed that the starter turned over much quicker. I decided to take off the battery and check the leads and earthing. The battery connectors are the quick change lever type and were very black inside. After cleaning with emery and wire wool, I could see they were copper inside. I also removed and cleaned the body earth. This morning, covered in snow, the car turned over quickly and started fine. Don't think I'll be changing the starter motor just yet. Time will tell if the problem has been solved.

hirsty

[Peter.N.]

Sounds like that was the problem, it often is.

Peter

[white exec]

Glad you seem to have nailed it. Battery connections are a common problem.
As I said, simple things first, before starting to throw serious money and time at starter motors.
Solid brass battery clamps are the best, but make sure you clean up the strands (back to clean copper) on the heavy cables when fitting them.

[hirsty]

OK having got the starter turning over quicker, I have noticed the engine turns over about 5/6 times before firing. Is this normal or is the fuel running back? Is there a non return valve in the fuel line that may be allowing fuel to run back? After running well serviced new company vehicles for 40 years that start first turn am I expecting too much from the old girl? Your comments as usual appreciated.

hirsty

[white exec]

If there's a priming button on the fuel filter, give that a few firm pushes before starting.
If it feels firm at first push after an overnight stand, then fuel is available. If it takes a few pushes before it goes firm, then there is air getting into the fuel line, and that will delay starting.

Recent cold weather won't be helping, either. Try operating the IGN switch a second time (after say 30 secs) to give a second burst of the glowplugs before cranking. This should show up whether glowplug/preheating is an issue.

[hirsty]

The fuel filter has been modified to use a Rover disposable type (prior to my ownership) and doesn't have a priming button. This has been renewed recently. The glow plugs are only 2 weeks old.

hirsty

[hirsty]

Ok so having changed the battery connectors to bolt down brass ones and cleaning all the connections, including visible earths, the car turns over much quicker. The first start this morning was difficult. The engine turns over quickly but doesn't fire until maybe the fourth or fifth attempt. Could the fuel be running back ? When it does finally start, I see a large blue cloud in the mirror. Any advice or suggestions please.

hirsty

[Peter.N.]

The blue cloud suggests that fuel has been entering the engine but its not being burnt which is an indicator of low compression but I have never seen one of these engines with that problem. Its a pity you don't have a primer as this should clinch the problem, you can get an aftermarket primer bulb and fit that, its only a question of cutting the pipe and fitting it in, but make sure you get the right pipe, its the feed from the tank not the one that goes back to it.

Peter

[hirsty]

When the monsoon finally subsided this morning, I took off the engine cover and checked all the fuel connections for tightness. A couple didn't seem as tight as expected so maybe a small ammount of air is being sucked in when the engine is cold. I tightened them up and will see how this affects things.

hirsty

[white exec]

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