RPM drop during slight acceleration

[Kurtly91]

I made a video of it make sure video quality is set at 1080p happend at 28 second second mark https://drive.google.com/file/d/1MhrCDKkGDXI51ghYJ3FJGHOrVKbYegen/view?usp=drivesdk

 

[Kurtly91]

Another question, when the auto was changed, did they also change the torque converter or reuse the original?

I ask only since I’m not sure whether it’s possible for the torque converter to play funny buggers with engine load (thus rpm) when you ease off the throttle. Maybe something to consider.

I don't know if the torque converter was changed , I had the transmission replaced by a friend of a friend

 

[Kurtly91]

I believe the throttle body contains the TPS and IAC. Cleaning a throttle body usually entails getting the gunk off the main air passage and off throttle plate itself.

If the throttle body has lots of gunk in it, cleaning can cause idle issues as the ECU has slowly learnt to cope with the clagged intake. Cleaning can upset this stored steering system and the engine doesn’t run sweet. There are relearn procedures that aid the ECU to reset its base but it doesn’t sound like that is your problem.

So how thoroughly the throttle body was cleaned and whether the IAC and MAF were cleaned and whether an IAC relearn procedure was done is a question to ask of the person who cleaned it. And supposedly you shouldn’t use carbi cleaner containing MEK as they can damage the MAF. There also are specific MAF cleaners to avoid such potential damage.

Thanks for that I'll get some MAF cleaner from super cheap and try that some time through the week

 

[Kurtly91]

What motor are we talking about v8 v6?

V6 engine

 

[Trevor loves holden.]

Looks like you have a dead spot on your TPS. Have you got a multimeter to test if the TPS is working, with ignition on you should be able to see the volts rise up, starting about .5v climbing to 5v in full throttle. If it not a steady climb or if it stops and starts then it be your TPS.

 

[Trevor loves holden.]

Oh also your ignition module could cause it as that's were the signal generates from.

 

[Kurtly91]

Thanks for everyone's help . I will just go ahead and buy a TPS and see how I go (don't have voltage meter)

I would prefer to order online then shop locally, i noticed there's a couple of cheap ones on eBay around the $12 my gut tells me i shouldn't buy those ones is there something that someone recommends?

 

[Skylarking]

There have been statements that you should use a genuine OEM throttle body and not some aftermarket unit which can cause issues. Even using a throttle body from another variant of your model supposedly can cause issues. Not sure if same goes for TPS or IAC but scan the forums as the answer may be within.

Also, a cheap digital multimeter can be had on eBay for less than cost of a few coffees, though for sweep measurements I prefer the older analog meters, also cheap. They can be handy tools to have so consider getting one

Anyway I always prefer trying to localise the issue rather than throwing parts at the problem but that’s just me. On that front, there are lots of videos on how to test correct operation of TPS and IAC on YouTube. So do consider doing some diagnosis as there is nothing worse than buying parts and then finding those parts substandard after finally going down the diagnosis path because the fault still exists

 

[Trevor loves holden.]

Yip, get yourself a multimeter jaycar are cheap then just google how to test the ohms or volts step by step on line. My nephew car today has been a prick bloody Holden cruze Its a 1.4L turbo 2012 nothing but issues, latest cooling fan not working what a headache, tested all the relays x5 all working, fuses x3 good, turn the A/C on fan kicks in, pull the relay fan comes on flat out pull the second relay fan goes to medium pull the 3rd fan runs on normal speed with A/C off, put all relays back in runs flat out with A/C off , turn the key off restart car no fan then coolant boils again. So multimeter is getting a workout, going to replace cooling sensor see if its the issue next but the temp is working on the gauge so I'm leaning towards the fan resistor. Any one has any input please share.

 

[Trevor loves holden.]

Got the Cruze coolant system working, if anyone has a problem with a cruze, the electric thermostat was sorting between inside pins to outside pins, I was getting 17.9 ohms out side harness and the inside mechanism once removed was reading 16.2 ohms, so replaced it 140 latter now all good, may help someone.