944S2 died on Thruxton Straight

[Cater_Racer]

Hi All,

Tom and I were playing at Thruxton yesterday, and it was going fine, apart from No Speedo?? Then after 6 laps the engine suddenly died on th back straight doing about 120 MPH.

Tom rolled it round to the pits. We tried re-starting but despite turning over fine it wouldn't start. It wasn't even trying??

So fuel? Injectors? Sparks? or is something to do with speed sensor....No speedo??

Any ideas, where to start. Tom has the car at home and next to it in the Garage is his S2 road car, so easy to swap relays etc. with a known running car.

Any help much appreciated.

 

[pse_SC]

Maybe an obvious but very common transaxle one, fuel pump relay, perhaps?

 

[vitesse]

Could also be something simple like a fuse with bad contact or broken/poor connector at the fuel pump,fuse board even the crank sensor connections .

 

[pse_SC]

Do you mean no speedo OR no rev counter?
Fuel relay operation is linked to rev counter, I believe, so perhaps the connection is there too?
Just a thought.

 

[Cater_Racer]

I think I said no speedo....
I meant no Speedo.
[]

Rev counter was working fine.

 

[924Srr27l]

I think I said no speedo....
I meant no Speedo.
[]

Rev counter was working fine.

What you like Gerry! no speedo but we were doing about 120mph!
So it died and you had to be towed back or it's spluttering?

You checked the obvious stuff ? change the DME Relay, fuel pump whirring?
Battery voltage, does the tacho needle move when you crank it?

Take off the Dizzy cap inspect it and the rotor contacts etc...

the speedo sensor comes off the gearbox I thought?

R

 

[pse_SC]

I think I said no speedo....
I meant no Speedo.
[]

Just trying to help with common possible fixes... hope you get it fixed soon, good luck [8D]

 

[Cater_Racer]

What you like Gerry! no speedo but we were doing about 120mph!
So it died and you had to be towed back or it's spluttering?

You checked the obvious stuff ? change the DME Relay, fuel pump whirring?
Battery voltage, does the tacho needle move when you crank it?

Take off the Dizzy cap inspect it and the rotor contacts etc...

the speedo sensor comes off the gearbox I thought?

R

Hi Roger,

No need for a tow, rolled back thru the chicane and made the box. It was pulling over 5,000 RPM in 5th.

I guess the suggestions above are about right (Thanks everyone), we've tried the DME relay, it's all cranking fine, so battery etc is ok.

I think fuel or sparks, compression is there or thereabouts otherwise it would crank like a stopwatch.

Regards

Gerry

 

[Waylander]

the main question is does the tacho bounce when you crank it over, if not its the reference sensor or its connections?

as far as I can see in the diagrams, the only time the speedo is used for reference is with Cruise Control,
think that might be a bit of a red herring

 

[pse_SC]

That’s what I was thinking...[]

 

[Cater_Racer]

I didn't think the Tacho was bouncing but Tom said it was.....

I think he can compare it with the red car today sometime.

Gerry

 

[Waylander]

Have to say, that if had cut out while you were flat out through church the outcome might have been a bit more exciting

 

[Cater_Racer]

Have to say, that if had cut out while you were flat out through church the outcome might have been a bit more exciting

 

[Cater_Racer]

We found it! Thanks everyone. Wire near gearbox unplugged

 

[924Srr27l]

We found it! Thanks everyone. Wire near gearbox unplugged

Ok so the speedo's back up and working but why did the engine die?

R

 

[Waylander]

was that the Speedo fixed, and has that fixed the ignition too,

if so that’s gone in the things to check folder