as the title says, when im driving a long and it doesnt matter what gear/speed im doing, when i let off the throttle the rpm needle jumps around and its quite annoying, has anyone had this issue and what was the cause, thanks.

 

car is a manual and its been smoke tested and nothing found leak wise.

Does the engine speed also go up and down, or is it just the tachometer reading that changes while the engine speed is constant?

Is this the same jalopy you asked about in June and failed to inform us of the outcome?

I'd recommend a diagnostic check to see if any fault codes flag up. 

Worth getting the MAF and lambda sensor looked at. 

3 hours ago, Steve Q said:

I'd recommend a diagnostic check to see if any fault codes flag up. 

Worth getting the MAF and lambda sensor looked at. 

absolutely no fault codes mate, i did have a vacuum leak caused by the downpipe which was fixed, maf is fine, lambda sensors havent been looked at though i dont think.

On 9/14/2022 at 9:27 AM, cliffcoggin said:

Does the engine speed also go up and down, or is it just the tachometer reading that changes while the engine speed is constant?

Is this the same jalopy you asked about in June and failed to inform us of the outcome?

sorry mate i thought i had replied, this is a different car, only the rpm needle flickers. 

When you say the needle flickers is it just the needle or is the engine revs definitely off. 

12 hours ago, Steve Q said:

When you say the needle flickers is it just the needle or is the engine revs definitely off. 

Literally il let off the throttle or when I blip when I’m driving the rpm needle will flicker, it doesn’t do this if I am stationary and rev, only when driving. It also happens when I am driving downhill without touching the clutch or accelerator. My rocker cover gasket is leaking but dno if that will have any affect on this scenario. 

Could it be clutch related? 

23 minutes ago, Steve Q said:

Could it be clutch related? 

i was thinking this but it was mapped recently by r-tech and they said my clutch was spot on. someone mentioned something about a clutch switch to me.

On 9/18/2022 at 9:02 PM, arron1995 said:

i was thinking this but it was mapped recently by r-tech and they said my clutch was spot on. someone mentioned something about a clutch switch to me.

Could be the switch. Was it doing it prior to the remap? 

On 9/21/2022 at 7:28 AM, Steve Q said:

Could be the switch. Was it doing it prior to the remap? 

sorry for the late reply steve, its done it since i bought it, so prior to the map.

I'd definitely look at getting the switch looked at.