Restless stepper motor

[taylormj4]

Hi all,
Been getting some 'interesting' issues with the Chimaera recently.
Starts fine but then after around 0.5mile, engine cuts out then back in really quickly (like full loss of power). Not enough to cause you to stop and if at idle, revs drop to around 500rpm but quickly recover.
Today, after driving to work, engine switched off, the stepper motor keeps making noises like its winding in and out, it keeps doing this then pausing for 10secs or so then doing it again. Engine is off but IGN is on.
Knackered stepper motor, or some fault with the ECU feeding the stepper signals when it shouldn't be ?

Matt

[V8 GRF]

If it's twitching like that I'd suggest it was knackered but try disconnecting the ECU for 30 seconds or so and then reconnect. The car should stall the first time you restart it and then the second time it should be OK. If that doesn't clear the problem I'd suggest you need a new stepper.

Beware however the OE ones are now being sold for somewhere in the region of £160 -£180 new and the cheap ones on ebay from Mexico or China are rubbish, I know I've had 3 or 4, so try to get hold of an original off a car that's had coilpacks fitted or similar.

[SILICONE KID]

I managed to get a interpart stepper motor £40 good quality and works perfect.Any decent motor factors can get them..

[V8 GRF]

SILICONE KID said:

I managed to get a interpart stepper motor £40 good quality and works perfect.Any decent motor factors can get them..

I think you were lucky, some work some don't. The one's I've had lasted a month or so then went faulty and some didn't from new, I know that's not unusual so it's very much a case of potluck and you get what you pay for.

[Chimpafrolic]

SILICONE KID said:

I managed to get a interpart stepper motor £40 good quality and works perfect.Any decent motor factors can get them..

Daz do you mean Intermotor?

http://www.smpeurope.co.uk/?p=smpeurope/catalogue&...

Intermotor part number: 14811

Part Type: Idle Control Valve

Personally I think Intermotor parts are very poor quality, I certainly wouldn't use them.

Interpart on the other hand are a plumbers supplier, great for bits for your Potterton boiler but not so good for TVR parts

http://www.interpartspares.co.uk/

Edited by Chimpafrolic on Friday 8th April 14:12

[SILICONE KID]

I put the intermotor next to a chinese £15 thing and it was nothing like..Looks the same as the OE stepper..

[Bassfiend]

Chimpafrolic said:

Interpart on the other hand are a plumbers supplier, great for bits for your Potterton boiler but not so good for TVR parts

http://www.interpartspares.co.uk/

Having had my Chim for 18 months *NOTHING* would suprise me!

Phil

[blitzracing]

V8 GRF said:

If it's twitching like that I'd suggest it was knackered but try disconnecting the ECU for 30 seconds or so and then reconnect. The car should stall the first time you restart it and then the second time it should be OK. If that doesn't clear the problem I'd suggest you need a new stepper.

Beware however the OE ones are now being sold for somewhere in the region of £160 -£180 new and the cheap ones on ebay from Mexico or China are rubbish, I know I've had 3 or 4, so try to get hold of an original off a car that's had coilpacks fitted or similar.

Odd my car had one made in Mexico from day one, that was identical to a replacement one I bought from a landie dealer for quite a lot. Worked perfectly. I agree the Chinese ones really are pot luck.

As for the stepper "reset", the normal pulse you hear is only when the ignition is turned off, as part of a system to get the stepper to its home position before a restart. The ECU feeds in more steps than the motor can actually do, so it buzzes when it hits the end stops, but why it should cycle I dont know unless the ECU is resetting for some reason????

[taylormj4]

Thanks for the advice chaps. Hadn't realised there was a problem with cheaper stepper motors so thanks for that too.
Will try the ECU disconnect and let you know if it helps.
Cheers, Matt

[GTvr]

I brought a cheaper stepper motor from Ebay about a year ago, had intermitant idle problems since fitting, a few months ago went to clean it and ended up with it in 2 parts, brought a new one from TVRPARTS and much better made and guess what no more idle problems.