Weird revs

[Benjamin Whiley]

Hey, My vs commodore esteem s2 is running really weird I’ll be sitting on 80+ and the revs fluctuate from like 3000 to 2700 and I don’t know why. Do you have any ideas I have put new spark plugs newer coil pack new leads new fuel filter and new crank angle sensor

 

[Skylarking]

Auto or manual?
Auto I suspect... check the oil level or better still do a service (oil, filter, etc).

 

[Benjamin Whiley]

Auto or manual?
Auto I suspect... check the oil level or better still do a service (oil, filter, etc).

Done a service 1500 km ago and yes auto

 

[Skylarking]

1500kms can be anywhere from one week to a year in time, though for most it tends to be 3 weeks. But did this issue just start to occur or has it been their since the trans service and being progressively getting worse?

And have you checked the trans fluid level in the last few days?

Ps: I’m assuming some auto slip or flaring is occurring which is why your see fluctuating revs. May be worth clearly indicating how the revs are actually changing... for example driving at constant speed at 100kph with revs siting at 2700rpm then they jump to 3000rpm then they go back to 2700rpm. Yhis could be helpful as others may know the vehicles gearing and what revs should be at a given speed... slipping/flaring should see revs increase... cause some other engine issue like idle control valve issue could see different behaviour to auto flaring.

 

[Benjamin Whiley]

1500kms can be anywhere from one week to a year in time, though for most it tends to be 3 weeks. But did this issue just start to occur or has it been their since the trans service and being progressively getting worse?

And have you checked the trans fluid level in the last few days?

Ps: I’m assuming some auto slip or flaring is occurring which is why your see fluctuating revs. May be worth clearly indicating how the revs are actually changing... for example driving at constant speed at 100kph with revs siting at 2700rpm then they jump to 3000rpm then they go back to 2700rpm. Yhis could be helpful as others may know the vehicles gearing and what revs should be at a given speed... slipping/flaring should see revs increase... cause some other engine issue like idle control valve issue could see different behaviour to auto flaring.

My revs are going down and you can feel it lose power kind of, also if I am going 80+ the revs are also fluctuating between 2400-2000rpm

the issue started just before I got it serviced about 4 weeks ago I thought I was misfiring but turns out it isnt

 

[losh1971]

Test your TPS.

 

[Benjamin Whiley]

Test your TPS.

How do I test it

 

[Skylarking]

TPS is basically a potentiometer where the resistance varies as the throttle is turned.

The TPS connector has power (5V?), earth and signal wires. You measure the voltage on the signal wire while slowly opening the throttle. The voltage should slowly rise as you open the throttle. The voltage should not jump around or drop to zero and back up to a voltage as you turn.

The best tool for doing such checks is an old style analog voltage meter.

Others would be able to chime in at specific pinouts and voltage levels.

More modern cars like VE or VF have OBD2 plug where you can plug on an ODB2 adapter and use your phone to read the TPS signal via a phone app. VS has ALDL wires within ODB plug which is a differet beasty.

You can find the VR/VS service manual within this post and DTC list here

 

[Benjamin Whiley]

Just put a new tps in still no go, would dfi be next ??

 

[vs-lover]

Personally I feel it's a trans issue as I had that with my Calais when I brought it back from Melbourne originally. I could be driving at 100k's and then suddenly the revs would skyrocket until I changed speed back down and reapply acceleration. I put this down to a trans that had done very little work (69,000k's) over 20 years and there was some kind of internal bypass of pressure.

Just my thoughts.............got to ask how many K's has your vehicle done ?