Intermittent starter

[taylormj4]

This morning the 450 started and got my daughter to nursery, then started to drive away. Thought "what am I doing, I have the roof on", pulled over to remove it, got all kitted up (hat etc) then tried to start and nothing . Fuel pump primes, ignition lights all on, but no solenoid click, nothing.
Rang helpful local TVR mechanic and he suggests starter motor faulty and may start when cooled down - he was right, span up after around 5 mins .
My question is how can, presumably the solenoid, fail due to heat but then work again once it cools ? Swollen plunger sticking in the housing ?
What I want to understand is, is this a replacement job as starter/solenoid is knackered, or will just a heat shield solve the problem ? It's a daily driver so reliability is key here.
Impressive that I get heat problems on a day like this, with temperatures in the negatives. Although, I did leave it to warm standing on the drive whilst I defrosted it, which is unusual.
Cheers, Matt

[taylormj4]

Have seen the various recommended repairs:
1. Mod-wise kit (reduces resistance/increases current to/reduces volt drop to starter)
2. Strip and regrease the solenoid (sticks when hot)
3. Replace the starter (same as 2 but more expensive ?)
4. Replace ignition switch

How many people have done any of the above ?
Option 2 sounds good to go for, although I didn't even see the ignition lights dim, which suggests that the solenoid wasn't jammed, it just wasn't drawing any current. Anyone agree ?

Is there a starter motor relay, should I be able to hear that click ?

Cheers, Matt

[Badmutha]

taylormj4 said:

Have seen the various recommended repairs:
1. Mod-wise kit (reduces resistance/increases current to/reduces volt drop to starter)
2. Strip and regrease the solenoid (sticks when hot)
3. Replace the starter (same as 2 but more expensive ?)
4. Replace ignition switch

How many people have done any of the above ?
Option 2 sounds good to go for, although I didn't even see the ignition lights dim, which suggests that the solenoid wasn't jammed, it just wasn't drawing any current. Anyone agree ?

Is there a starter motor relay, should I be able to hear that click ?

Cheers, Matt

The mod-wise kit is always worth fitting IMO, only about 25 quid and 20 minutes work and should guarantee against any hot starting problems in the future, unless you do have a dodgy starter of course, but still a worthwhile mod.in any case.

[Colin RedGriff]

taylormj4 said:

Have seen the various recommended repairs:
1. Mod-wise kit (reduces resistance/increases current to/reduces volt drop to starter)
2. Strip and regrease the solenoid (sticks when hot)
3. Replace the starter (same as 2 but more expensive ?)
4. Replace ignition switch

How many people have done any of the above ?
Option 2 sounds good to go for, although I didn't even see the ignition lights dim, which suggests that the solenoid wasn't jammed, it just wasn't drawing any current. Anyone agree ?

Is there a starter motor relay, should I be able to hear that click ?

Cheers, Matt

1 adds the starter motor relay that TVR removed which helps. I've done this and also replaced the starter motor and so far no more problems.

I also believe that the modwise kit also helps protect the immobiliser circuit for the starter moter which can be damaged by the absence of the relay.

[taylormj4]

Colin RedGriff said:

I also believe that the modwise kit also helps protect the immobiliser circuit for the starter moter which can be damaged by the absence of the relay.

I presume the kit doesn't bypass the immoboliser then, making the car less secure by connecting the starter/solenoid straight to the battery ? The insurance company might have something to say otherwise !

Matt

[captaintact]

Does the immobiliser not only disconnect the fuel relay NOT the starter solonoid?

[Colin RedGriff]

taylormj4 said:

Colin RedGriff said:

I also believe that the modwise kit also helps protect the immobiliser circuit for the starter moter which can be damaged by the absence of the relay.

I presume the kit doesn't bypass the immoboliser then, making the car less secure by connecting the starter/solenoid straight to the battery ? The insurance company might have something to say otherwise !

Matt

No it doesn't. The immobiliser still isolates the starter circuit.

captaintact said:

Does the immobiliser not only disconnect the fuel relay NOT the starter solonoid?

The immobiliser (at least on my Griff) cuts both the fuel pump and the starter circuit.

[waylison]

Had exactly the same problem on my 400. It turned out to be a worn out starter motor. The bronze bearing in the bracket had popped out allowing the rotor spindle to run off center. Rebuild guy said it was beyond economic repair. A new starter motor costing £85 sorted it and the engine spins over much quicker now which makes starting better. As a belt and braces procedure I made a heat shield to go between motor and exhaust above.





Made from white faced aluminium, 0.6mm thick.

Wayne.

[captaintact]

Nice mod Wayne!

[taylormj4]

Hi Wayne,
Nice work. A quality piece of Engineering that!
Just to check I understand, this bronze bushing is the one that supports one end of the main motor spindle ?
Was this causing the same symptoms as I have: stick when hot and then frees up again when cold? Did you hear nothing when you tried to start or was the solenoid clicking as it tried to through the starter motor gear into the flywheel ?

Gonig to get the car on the jacks tomorrow hopefully and see if there are any obvious wiring issues and then maybe drop the starter for an inspection.

Cheers, Matt

[waylison]

Hmmmm, I'm supposed to get an email reply notice for your reply matt, but haven't, hence late to respond.......sorry.......but hope I can still help...

when starting the car from cold, no problems, always started fine. But when hot it would sometimes fail to spin the engine over and all i would hear is the 'click click' of the solenoid.

The bronze bearing missing was the one on the bracket that supports the end of the main rotor shaft that goes into the bellhousing.

Wayne

[taylormj4]

waylison said:

Hmmmm, I'm supposed to get an email reply notice for your reply matt, but haven't, hence late to respond.......sorry.......but hope I can still help...

when starting the car from cold, no problems, always started fine. But when hot it would sometimes fail to spin the engine over and all i would hear is the 'click click' of the solenoid.

The bronze bearing missing was the one on the bracket that supports the end of the main rotor shaft that goes into the bellhousing.

Wayne

Hey no problem Wayne,
That's different to mine then. I don't get the clicking. I get nothing at all. Have had the hear-a-click-only failure before and recognise that as a solenoid problem. Having no click is a new one on me. Haven't had chance to look at it yet. Didn't fancy trying to drive up the ramps in all the snow. It has enough problem getting enough grip to drive on the flat in those conditions. Maybe this weekend. Hoping to find a partially broken cable or something obvious that can be fixed.

Cheers, Matt

[spend]

Immobilizer (internal) relay or ignition switch is normally the problem if no click at all. Sticking a test light on the solenoid, ignition & immob can tell you where the fault occurs.. Once you identify the cabling to/from the immob it is easy enough to bypass if you want.

[taylormj4]

spend said:

Immobilizer (internal) relay or ignition switch is normally the problem if no click at all. Sticking a test light on the solenoid, ignition & immob can tell you where the fault occurs.. Once you identify the cabling to/from the immob it is easy enough to bypass if you want.

Hi Spend,
Thanks for that. Would that be affected by heat, i.e. begin working again after a short period of cooling down ? Presume it is located under the dashboard top ?
I took a look at the starter last weekend. All wiring looks fine. I found two heavy current wires, one coming from the 100A fuse (presumably from the battery or alternator) and the other coming from higher up in the chassis around the gearbox area. There was also a smaller black wire going to the solenoid, presumably the wire that fires the solenoid when the key is turned.

I guess I'll have to wait until it happens again, to get more information, e.g. do the IGN lights dim when the key is turned (indicating solenoid is trying to move) or nothing at all (wiring fault or immobiliser etc)

Cheers, Matt

[taylormj4]

Ok, so it did it again today. Gave me a chance to investigate a bit more. Happened as before, after 2 short journeys only this time I left the car so alarm had been set.

When I turn the key, the fuel pump primes, all IGN lights come on as normal but there is no starter and no click from the solenoid or any relays that I can hear. The IGN lights on the dash do not dim which suggests that the coil in the solenoid is not drawing any current so maybe not getting any feed at all rather than it being stuck. Am presuming the solenoids draw a lot of current, they look pretty meaty and draw a fair arc when I've bench tested before.

I am now suspecting wiring to the solenoid or something to do with the immobiliser. Can someone tell me where all of this wiring is and the immobiliser, maybe better to PM me as it is too sensitive for the forum?

The car had already been standing for around 10 mins before attempting to start and needed another 5 mins before mysteriously staring again. This is the bit that bugs me. Why would it 'repair' itself again. A strange problem. Needless to say, I'll be holding off the cost of a replacement starter motor/solenoid until I'm convinced that's the problem.

Cheers, Matt

Edited by taylormj4 on Thursday 13th January 11:04

[spend]

You have to get the dash off & footwell out to investigate - the wires aren't colour coded just typically all black or yellow (pretty dumb idea of added paranoid security bod if you ask me).

Once you've found the pair across the immob, just hotwire them to see if that is the root of the problem. Then you can mull over long term solutions...

[Simon says]

taylormj4 said:

Colin RedGriff said:

I also believe that the modwise kit also helps protect the immobiliser circuit for the starter moter which can be damaged by the absence of the relay.

I presume the kit doesn't bypass the immoboliser then, making the car less secure by connecting the starter/solenoid straight to the battery ? The insurance company might have something to say otherwise !

Matt

If done correctly no,in fact doing the starter relay mod will prolong the lifespan of the immobilisers internal relay/s and keep the Cat 1 category intact so everyone's a winner

[taylormj4]

Simon says said:

taylormj4 said:

Colin RedGriff said:

I also believe that the modwise kit also helps protect the immobiliser circuit for the starter moter which can be damaged by the absence of the relay.

I presume the kit doesn't bypass the immoboliser then, making the car less secure by connecting the starter/solenoid straight to the battery ? The insurance company might have something to say otherwise !

Matt

If done correctly no,in fact doing the starter relay mod will prolong the lifespan of the immobilisers internal relay/s and keep the Cat 1 category intact so everyone's a winner

First, good idea Spend thanks. I guess I'll have to do some wire tracing. Was hoping never to have to remove the dash again as my walnut is now heavily cracked (fanah fanah) and I suspect it will disintegrate completely if disturbed. Ah well.
Next, Simon: Thought they were Cat 2 due to the microwave sensor being used ? Are you saying that there isn't a relay in the circuit to the starter solenoid ? I didn't think ignition barrel switches could take that amount of current. Also how does adding a relay in series with the immoboliser relay help to preserve it ? Do you have a circuit diagram for the original and modded circuits to help me understand better.

Thanks, Matt

[Cider Andy]

taylormj4 said:

Are you saying that there isn't a relay in the circuit to the starter solenoid ? I didn't think ignition barrel switches could take that amount of current. Also how does adding a relay in series with the immoboliser relay help to preserve it ? Do you have a circuit diagram for the original and modded circuits to help me understand better.

Thanks, Matt

In the factory set-up there is no active relay in the circuit between the ignition switch and the starter solenoid (except the supply passes through the contacts of an internal passive relay in the immobiliser). The Modwise kit introduces a relay between the immobiliser and the solenoid. The current passing through the ignition switch and immobiliser now simply operates the new relay which, in turn, supplies the solenoid with a fused supply direct from the battery.