Revy rev rev

[Chapperz]

I know this has been asked but it`s hard working out which post to go from so quick bit of help please.

When cold the car (182) revs do not drop back to 1100 like they should but stay up around 2/3k and bounce around a bit but slowly comes down most of the time. When warm it doesn`t do that bit but instead when changing gear the revs go up slightly before dropping.

What bits in what order should I check

Throttle body - Clean?
Map sensor?

What else?

Cheers guys

 

[Raceface_13]

Id give everything a good clean and see how it effects it (if at all) they can/do run abit rough cold (some say its timing being out others dont)

 

[STEVE.M]

I know this has been asked but it`s hard working out which post to go from so quick bit of help please.

When cold the car (182) revs do not drop back to 1100 like they should but stay up around 2/3k and bounce around a bit but slowly comes down most of the time. When warm it doesn`t do that bit but instead when changing gear the revs go up slightly before dropping.

What bits in what order should I check

Throttle body - Clean?
Map sensor?

What else?

Cheers guys

If you don`t have an air leak (unlikely), then I`d say that`s a poor connection/ wiring problem.
Does the car ever go into limp mode?

 

[Chapperz]

Hey @STEVE.M - Nah no limp mode

The engine bay isn't the cleanest - would prefer it to be mechanical rather than electrical :laughing:

 

[STEVE.M]

Hey @STEVE.M - Nah no limp mode

The engine bay isn't the cleanest - would prefer it to be mechanical rather than electrical :laughing:

How long have you had this fault, is it the same car you changed the gearbox in 2014, and if so, how much use has it had since?

 

[Chapperz]

Damn was that back in 2014! Yeah its the same betty, owned it 10 years now. Its my daily so lots, i noticed the fault after doing the Aux belt, but it {may} have been around before.

 

[Chapperz]

I did the belt a couple of months ago

 

[Coops Mk1]

I'd clean the throttle body in the first instance see if it's just sticking slightly

 

[STEVE.M]

I did the belt a couple of months ago

Any chance you damaged the vacuum hose to the carbon canister when changing the belt?

Working on the basis of checking everything that costs nothing but your time, I`d cap the acoustic valve & carbon canister take off points, nip up the upper & lower inlet manifold bolts, & clean all the fuses, relays & connecting plugs you can find in the engine bay.

If you clean the throttle body, do not attempt to move the flap, though check that there is no wear in the spindle & that it is closing uniformly, not at an angle.

I would not attempt to remove the MAP sensor, as you will very likely snap one of the retaining pegs, its worth checking that it, and the air temperature sensor are firmly located & not leaking though.

I am assuming that the coolant level is correct, and the thermostat is not stuck open and the engine is getting up to temperature normally.

Have you had the top inlet off recently to change the spark plugs?

If none of this achieves any improvement, you will need to get it plugged into CLIP somewhere & get some live readings rather than start guessing where the fault lies.

Good luck!

 

[Chapperz]

@STEVE.M Cheers mate, far to drunk/hungover, over the bank hol to reply.
I`ve probably messed up the carbon canister bits, so going to try that first. I did pop the top of the CC, when doing the AUX belt, and struggled to put it back on. Then throttle body.

Cheers for letting me know a sensible way to attack this.

BTW, why don`t move the flap on the TB, I swear i`ve poked it open to watch it close in the past?

P.s. all assumptions made are correct

 

[STEVE.M]

@STEVE.M

BTW, why don`t move the flap on the TB, I swear i`ve poked it open to watch it close in the past?

You run the risk of stripping the cogs.
You have probably moved the flap on a cable operated body, which is a different game.

 

[Chapperz]

I did it on this one 😂, think it was to check it returned to close smoothly.

 

[STEVE.M]

I did it on this one 😂, think it was to check it returned to close smoothly.

They don`t spring shut, it`s all driven by the motor.
This is the proper bit of kit, though I have never seen one.

 

[Louis]

Mine sprung shut when i pushed the flap up to clean it out. Didn't seem to do any harm

 

[Amos91]

Sounds pretty normal from my experience, particularly after the RsTuner map.

For the first 1-2 minutes, the revs on mine fall but at a slower rate than warm.

 

[Chapperz]

Sounds pretty normal from my experience, particularly after the RsTuner map.

For the first 1-2 minutes, the revs on mine fall but at a slower rate than warm.

Did the map years ago mate, its defo running/revving strange.