Engine stalling

[griff2be]

My Griff 500 sometimes stalls when I brake for junctions or take my time when changing down. The revs drop really low - sometimes it recovers to normal idle, other times it stalls. It seems more prone to doing this whilst braking downhill - but that ight be coincidence.

Does anyone have any ideas what might be causing this?

The car had a new stepper motor yesterday, a new camshaft last week (TVR Power), and a coil and HT lead 2 weeks before that. And I run it on Optimax....

Running out of ideas...!

(Is there a road speed sensor that talks to the ECU, and could it be that?)

Thanks

Andy

[Leadfoot]

Yes there is, yes it could, but (IIRC) there is only one sensor which supplies the speedo & ecu - so if your speedo is working normally at low speed it's unlikely to be that. What speed does it start registering at?

[GreenV8S]

quote:My Griff 500 sometimes stalls when I brake for junctions or take my time when changing down. The revs drop really low - sometimes it recovers to normal idle, other times it stalls. It seems more prone to doing this whilst braking downhill - but that ight be coincidence.

Does anyone have any ideas what might be causing this?

The car had a new stepper motor yesterday, a new camshaft last week (TVR Power), and a coil and HT lead 2 weeks before that. And I run it on Optimax....

Running out of ideas...!

(Is there a road speed sensor that talks to the ECU, and could it be that?)

Thanks

Andy

Wiring fault on the stepper? I would have thought this would trigger one of the 'out of travel' stepper motor fault codes in the ECU, have you checked?

[griff2be]

Speedo works fine at all speeds. The odometer jammed 2 months back but was sent off for repair.

Haven't checked the stepper circuit. It was reading a fault code 48 (which is stepper motor/mechanical fault) when it was diagnosed as needing a new cam. TVR Power were supposed to do the stepper motor but due to a communication problem with the dealer, didn't and stuck it in the post to me, I fitted and set it up yesterday. Haven't had the fault codes checked since before the cam was changed. Sounds like I need to.

Is there a common fault with the stepper wiring?

Thanks

Andy

[gjm]

seems to be quite a bit on this - and lots of useful replys. have a look at these postings
www.pistonheads.com/gassing/topic.asp?t=17172&f=9&h=0
www.pistonheads.com/gassing/topic.asp?f=9&h=0&t=10725
www.pistonheads.com/gassing/topic.asp?f=9&h=0&t=15563
noticed a common thread? - yep - these problems seem associated with my griff - problem not yet resolved!
ps - iam not sure if this is the correct way to post a link but i hope it works

[dawgie]

I had this exact same problem on my 4.0 Chimaera.

Turned out merely to be the setting of the 'base idle' which when twiddled by TVR specialist was fine.

Cost - £0 !!

[schueymcfee]

Mine does exactly the same thing and mainly going down hill too! I have changed the stepper too but to no avail.

Let us know how you get on.

[simont]

Try changing the two engine management relays, worked for me

[dai capp]

I've come across this before and the problem was first solved by tracing the fault to a badly soldered transistor in the ECU.

Also it can happen with carbon build ups in the cylinder head valves, especially if it gets used in cities a lot, though this is usually accompanied with a loss of power when running.

Hope this helps

Cheers

DC