Idling inquiry.

[groucho]

Since my Griff has come back from it's service it seems to be having some minor idling woes. Sometimes it will go very low about 200 and even stop and other times it will idle at 1,500. You can tell it's idling incorrectly when you change down gear, the revs don't drop or fall too much.
The weird thing is, if you stop for 30 seconds and let it idle at the fast or slow speed, it sorts itself out and idles at the correct rate and stays like it.
I've cleaned the SM, which is only a year old.

Any ideas, if it's not to hard I'll have a look at it myself.

Cheers [pic]http://smiley.onegreatguy.net/graucho.gif[/pic]

[2 sheds]

best ask the garage if they adjusted / changed anything, it could be many things first i would check is: incorrect throttle pot setting or failure, you need a digital multimeter to check this, insert meter prongs into the loom plug, brown & blue wires you need .33v (+ or- .01v )at throttle closed position.

[Hoover33]

Mine sticks at about 1500-2000 revs... and then drops to circa 1000 after about 30secs when stopped

[mick_coupe]

Hoover33 said:

Mine sticks at about 1500-2000 revs... and then drops to circa 1000 after about 30secs when stopped

My Chim was exactly the same when i bought it..setting throttle pot as above cured the problem.

Mick

[groucho]

Cheers for that guys, I'll have to go and buy a mutimeter. What's the procedure if it's not .33v, it doesn't seem to say much about it in the bible.

If it's easy enough I'll do it, save me taking a day off work and going down to exeter, or should I leave it to the experts?

[mick_coupe]

Mine was reading about .39v if i remember correctly..i slackened the two screws but left them tight enough so that it woudn't move by hand and tapped one end with the handle of a screwdriver (not very technical i know ) until the the voltage was right...then retightened the screws.
Only takes 5 mins...Mick

[Guillotine]

after 30 secs of non movement, the ecu hits its own pre set rev value, usually 1100revs.

sounds like leaking plenum (if they had it off)
dirty stepper - clean with spirits
throttle pot/sticking throttle. check cable run, pot value etc.

andy
www.ballisticbanana.co.uk/tvrmonster.htm

[groucho]

So I've gone and bought one but don't know how to use it, no instructions . Which holes do the red and black plugs go into and where do I turn the dial on the multimeter?

Here are some pics.


And what the hell is this?


Sorry if these questions seem numptyish, but never used one before.

[groucho]

Update: Found the instructions on the floor.
Let's have a read of them to see if I can get a grip.

[GreenV8S]

groucho said:

Which holes do the red and black plugs go into and where do I turn the dial on the multimeter?

Black lead always goes in the socket labelled COM (common).
Red lead in the middle socket. (The only time you would put the red lead in the left socket (labelled 10A MAX) is for measuring current. If you don't know what this means, don't use that socket.)
Start with the dial set to V/20 (20 Volt range), if the Voltage reading is less than 2V then change it to V/2000m (2000 millivoltt range) for greater accuracy.

groucho said:

And what the hell is this?

Looks like a thermocouple (temperature sensor). Plug it in, move the switch to oC and it will show the temperature of the tip of the lead.

[groucho]

2 sheds said:

best ask the garage if they adjusted / changed anything, it could be many things first i would check is: incorrect throttle pot setting or failure, you need a digital multimeter to check this, insert meter prongs into the loom plug, brown & blue wires you need .33v (+ or- .01v )at throttle closed position.

Does the loom plug need to be separated at all? I couldn't find anywhere to put the plugs, they're too thick. Which plug for which colour wire? Does the ignition need to be on or does the car need to be started? One thing I did notice when I took it off is that the throttle pot is slightly broken around part of the circumference, this is definitely affecting the car as it's now idling at 600 rpm.

mick_coupe said:

Mine was reading about .39v if i remember correctly..i slackened the two screws but left them tight enough so that it woudn't move by hand and tapped one end with the handle of a screwdriver (not very technical i know ) until the the voltage was right...then retightened the screws. Only takes 5 mins...Mick

What did you tap to change the voltage? Pic above.
Anyway it looks as if it's all academic, I need to buy a new one. When I get a new one is there any setting up to do, or is it just 'plug & play'?

Thanks for your ongoing help, just trying to learn a bit.

PS: Anybody know how much a new throttle pot is?


>> Edited by groucho on Sunday 26th June 17:23

[mick_coupe]

"What did you tap to change the voltage? Pic above.
Anyway it looks as if it's all academic, I need to buy a new one. When I get a new one is there any setting up to do, or is it just 'plug & play'? "

I tapped the plastic housing..in effect rotating the throttle pot slightly.The mounting lugs are elongated.

A new one will have to be set up the same.

I think a new one is around £40.

Ignition on.

I used two spikes to go into the wire's.

Mick




>> Edited by mick_coupe on Sunday 26th June 18:40

[groucho]

groucho said:

"What did you tap to change the voltage? Pic above. Anyway it looks as if it's all academic, I need to buy a new one. When I get a new one is there any setting up to do, or is it just 'plug & play'? "

mick_coupe said:

I tapped the plastic housing..in effect rotating the throttle pot slightly.The mounting lugs are elongated. A new one will have to be set up the same. I think a new one is around £40. Ignition on. I used two spikes to go into the wire's. Mick

What through the plastic cover? Which plug, red or black, for which wire, blue and brown?

Cheers.

[mick_coupe]

I pulled the corrugated cover on the wires back and went into the wires with the spikes.

Mick

[mick_coupe]

Try this www.rpiv8.com/carbs-2.htm

Mick

[groucho]

Thanks Mick, that certainly helps. One last question if I dare? What colour plug for what colour wire? as they are different colour wires on the link.

Is it red plug for brown wire and black plug for blue wire?

I'll shut up now I promise.

[mick_coupe]

groucho said:

Thanks Mick, that certainly helps. One last question if I dare? What colour plug for what colour wire? as they are different colour wires on the link. Is it red plug for brown wire and black plug for blue wire? I'll shut up now I promise.

Not sure what you mean...looks like i can see the blue and brown wire on your pic ?

Mick

[groucho]

These thingies. Which one goes for which colour wire in the loom?

Cheers.

[Ballistic Banana]

this thread might help groucho THROTTLE POT RESETTING

I poked a straightened paper clip down the connector and then use the crocodile clip adapters onto them, BECAREFUL they dont touch each other or any other metalwork.

BB