Starter Problems

[martinj999]

Hi Everyone,
I have been having starting problems recently, been down the hot start Modwise, and bought new starter motor. When I went to replace the starter motor, I noticed the 100A fuse connections were loose, tightened them and the problem went away. I was wondering if anyone had any thoughts on why these loose connections might cause the starter to fail? Looking at the wiring diagram the main power to the starter is connected direct to the battery, before the fuse.

[Cider Andy]

The 100A fuse fitteded to the chassis near the starter motor won't cause any problems starting unless the battery hasn't been charging. Reading betwen the lines I imagine you already knew that.

What are the starting problems you've been having?

[bigdods]

Possibly the loose fuse has prevented your battery from charging. When my battery was dying it had all the symptoms of hot start problem but took a new battery to cure it. If you have the hot start kit make sure you fit it, it does work and may save you from a fried immobiliser later on.

[cloggy]

[quote=bigdods]Possibly the loose fuse has prevented your battery from charging. When my battery was dying it had all the symptoms of hot start problem but took a new battery to cure it. If you have the hot start kit make sure you fit it, it does work and may save you from a fried immobiliser later on.[/quote
Scott, what exactly is a 'hot start kit'?
I don't have the problem but would like to know.

[Cider Andy]

cloggy said:

what exactly is a 'hot start kit'?

A search on 'hot start' in this forum will return a lot of results.

The wire that carries the current to operate the starter motor solenoid is, in places, thin and it passes through the immobiliser. Both these factors can cause a voltage drop on the wire. The solenoid mechanism itself is weakened with age and heat cycling (because of the hot environment it sits in) and it can easily stick. A combination of all these factors can cause the solenoid to be not supplied with enough current to operate it. The 'hot start' kit places a relay in the circuit such that the 'thin' wiring and the immobiliser part of the circuit now only operate a tiny relay, the relay then provides a better supply to the solenoid direct from the battery eliminating the voltage drop.

It will, of course, never be a fix for a failed solenoid but it will certainly prolong its useful life.

[bigdods]

Cider Andy said:

cloggy said:

what exactly is a 'hot start kit'?

A search on 'hot start' in this forum will return a lot of results.

The wire that carries the current to operate the starter motor solenoid is, in places, thin and it passes through the immobiliser. Both these factors can cause a voltage drop on the wire. The solenoid mechanism itself is weakened with age and heat cycling (because of the hot environment it sits in) and it can easily stick. A combination of all these factors can cause the solenoid to be not supplied with enough current to operate it. The 'hot start' kit places a relay in the circuit such that the 'thin' wiring and the immobiliser part of the circuit now only operate a tiny relay, the relay then provides a better supply to the solenoid direct from the battery eliminating the voltage drop.

It will, of course, never be a fix for a failed solenoid but it will certainly prolong its useful life.

The original setup in a Range Rover had a seperate Relay to feed the starter solenoid. TVR in their wisdom decided to do away with that relay , the the solenoid is fed direct from the immobiliser and has caused a number of failures (lots of threads on this) due to the excessive current passing through. Also when things start getting a bit tired it cant pass enough current when things get hot hence the name 'hot start problem'. The hot start kit is simply a relay and a few wires that can be fitted by anyone in about 20 minutes. Buy it from modwise for a few ££ its very cheap and it fits into the wiring in the passenger footwell.

[cloggy]

bigdods said:

Cider Andy said:

cloggy said:

what exactly is a 'hot start kit'?

A search on 'hot start' in this forum will return a lot of results.

The wire that carries the current to operate the starter motor solenoid is, in places, thin and it passes through the immobiliser. Both these factors can cause a voltage drop on the wire. The solenoid mechanism itself is weakened with age and heat cycling (because of the hot environment it sits in) and it can easily stick. A combination of all these factors can cause the solenoid to be not supplied with enough current to operate it. The 'hot start' kit places a relay in the circuit such that the 'thin' wiring and the immobiliser part of the circuit now only operate a tiny relay, the relay then provides a better supply to the solenoid direct from the battery eliminating the voltage drop.

It will, of course, never be a fix for a failed solenoid but it will certainly prolong its useful life.

The original setup in a Range Rover had a seperate Relay to feed the starter solenoid. TVR in their wisdom decided to do away with that relay , the the solenoid is fed direct from the immobiliser and has caused a number of failures (lots of threads on this) due to the excessive current passing through. Also when things start getting a bit tired it cant pass enough current when things get hot hence the name 'hot start problem'. The hot start kit is simply a relay and a few wires that can be fitted by anyone in about 20 minutes. Buy it from modwise for a few ££ its very cheap and it fits into the wiring in the passenger footwell.

Ta muchly.

[martinj999]

Thanks for the responses, my problem seems to come and go, but by tightening the fuse connections seemed to fix it (for a while) looking at the wiring diagrams I can't see why this would happen! The problem has come back again today and I know for sure the connections are good. I have a new starter motor to fit so this is my next step. I was wondering about the immobiliser, does this just break the link to the solenoid or something more devious in the ECU? When I can't start the car, there's no click from the solenoid but I can bump start it. When I get to the point when it won't re-start, if I wait for the car to cool down, I mean really cool down, several hours later, it starts fine, so I don't think it's the battery.

[bigdods]

martinj999 said:

there's no click from the solenoid

Might be an immobiliser problem. Have you tried hitting the underneath of the dash on the passenger side , I *think* that sometimes helps unstick things. Have a look through previous threads on the subject for more detail.

[blujay10]

The " dash board tap " should work as a temporary measure, however, in my case, it meant the immobiliser was on the way out.

[martinj999]

I've never tried the 'tap' ... thanks for that, I'll give it a go, how about a 5 lb lump hammer?

[S7Paul]

I've had a range of starting problems over the last few weeks, and assumed that because the car's always hooked up to an Accumate, and because the battery voltage looked fine, it couldn't have been a battery problem. Well, having checked everything else, I eventually tried a new battery. Problem solved! It seems that although the voltage readings were OK (admittedly just after I had disconnected the Accumate) it simply didn't have the cranking power to turn the engine over fast enough. I suppose that because it must have deteriorated over time, I hadn't noticed the engine cranking speed gradually reducing. I've now fitted a 630A Varta item, and it's cranking faster than I've ever heard it before.

[martinj999]

I think I'll change the battery as well to be on the safe side, I expect it's the original or at least 6 years old by now. Thanks for the info

[martinj999]

I had the problem today and the 'hit the dash on the passenger side' worked! What is the cause of this ? Looks like I'm getting closer to fixing it ... TIA

[blujay10]

martinj999 said:

I had the problem today and the 'hit the dash on the passenger side' worked! What is the cause of this ? Looks like I'm getting closer to fixing it ... TIA

Dash tap works because it frees a relay that is sticking as it gradually wears out/burns out as not up to the job. New immobilisers have much heavier duty relays. Sorry that's not very technical, but if you need a better explaination, Carl Baker is your man! I use my chim daily and so the tap worked for a couple of weeks, until I had to bite the bullet and get it fixed. Good luck!

[martinj999]

Thanks for that, I'll get an immobiliser on order ...