Engine keeps rev-ing when accelerating..
Engine keeps rev-ing when accelerating..
Author
Discussion

KillerJim

Original Poster:

972 posts

232 months

Sunday 10th August 2008
quotequote all
Hi,

Got a weird problem here..

I took the Sag out for a run today and was on my way home when I noticed that she wasn`t popping and banging on the overrun as she normally does. After a minute I realised that the car was still rev-ing (as if I had the foot on the gas) when I hadn`t..

Now, it doesn`t happen when I accelerate slowly or am crusing - just when you give it some power (mind u, not that much as it was wet).

If I accelerate in this manner and go to change gear (i.e. clutch depressed, so neutral) the car will rev up a few thousand RPM and sort of stay there, if I touch the gas pedal at all it will drop down to 1500rpm and then idle..

The car's going in for a service in about 2 weeks (full 12k service - the "works" as such) but I`m wondering has anyone else had this? or knows what it could be?

Thanks!

James

keirv6

66 posts

273 months

Sunday 10th August 2008
quotequote all
I would be checking the thottle linkage and cable.

GreenV8S

31,017 posts

313 months

Sunday 10th August 2008
quotequote all
I'd suspect either the pedal catching on the carpet, the the cable itself starting to fray and stick inside the outer sleeve.

VARLEYHYD

2,244 posts

236 months

Monday 11th August 2008
quotequote all
This photo may help see where the cable fails



G

Whitey

2,508 posts

313 months

Monday 11th August 2008
quotequote all
or the return spring at the other end of the cable under the airbox or any part of the butterfly mechanism

KillerJim

Original Poster:

972 posts

232 months

Monday 11th August 2008
quotequote all
Thanks guys, I don`t plan on moving her until I drop her to get serviced but I`ll have a look at those parts to see if I can spot any problems!

Thanks again!

Chris Marriott

183 posts

235 months

Tuesday 12th August 2008
quotequote all
Hi, I had this I ended changing the acc. cable and it made no difference so they cleaned all the peddle box out springs etc now good as gold.

KillerJim

Original Poster:

972 posts

232 months

Tuesday 12th August 2008
quotequote all
When you say they cleaned out the peddle box, you mean the mechanism around the accelerator pedal?

Any idea how they cleaned it? I.e took it apart and de-grease/re-greased things?

J

Chris Marriott

183 posts

235 months

Wednesday 13th August 2008
quotequote all
TBH I dont really know. Martin at Racing Green took care of it for me. I watched them change the cable and they still wernt happy so I left them to it and collected it the folowing day pops and bags were back. I think it was just as you said, regreased etc.

Chris Marriott

183 posts

235 months

Wednesday 13th August 2008
quotequote all
TBH I dont really know. Martin at Racing Green took care of it for me. I watched them change the cable and they still wernt happy so I left them to it and collected it the folowing day pops and bags were back. I think it was just as you said, regreased etc.

JonRB

80,044 posts

301 months

Wednesday 13th August 2008
quotequote all
My Sag doesn't pop or bang.

Apart from this one time with the engine. Not sure if it went pop, or bang, though. evil

KillerJim

Original Poster:

972 posts

232 months

Tuesday 19th August 2008
quotequote all
Just a little update..

After figuring out how to remove the panel around the pedals I had a good look at the cable and it looks fine.

Couldn`t see anything wrong with the other end of it either!

I`m wondering if the ECU is re-ving the engine but I`m not sure how it can do that - does it even have access to the throttle?

Once the rain has stopped here I will take her for a run tomorrow to see if she's still doing it, still less than a week to the service!

J

TVR_owner

3,349 posts

220 months

Tuesday 19th August 2008
quotequote all
KillerJim said:
Just a little update..

After figuring out how to remove the panel around the pedals I had a good look at the cable and it looks fine.

Couldn`t see anything wrong with the other end of it either!

I`m wondering if the ECU is re-ving the engine but I`m not sure how it can do that - does it even have access to the throttle?

Once the rain has stopped here I will take her for a run tomorrow to see if she's still doing it, still less than a week to the service!

J
Is the cable partially seized and maybe just requires lubrictation?

tail slide

2,169 posts

276 months

Wednesday 20th August 2008
quotequote all
scratchchin Does sound like one thing I've come across; the plastic fuel line being tied too close to the accelerator cable, rubbing against it so it (sometimes!) slows the accelerator cable trying to return all the way to it's stop.

You could see it with a torch, below the throttle stop.

Not good for several reasons.... smokin



Edited by tail slide on Wednesday 20th August 21:14

KillerJim

Original Poster:

972 posts

232 months

Thursday 21st August 2008
quotequote all
Going to take the car for a run tomorrow (finally stopped raining) so I`ll see if its still the case and have a good look.

Thanks for all the replies..

J