Help with lost power under 3k revs

[SimiRockStar]

Hello everybody..

I just did a litle engine "rebuild" on my 197. Reason - oil consumption and huge blue smoke clouds on 4500k revs and up...

- So crankshaft bearings, piston rings, valve seals, did valves with paste, did the "grinding" of engine head ( hope google traslate did the job hh) , since i work in a official renault workshop, all material is OEM , did get "good" price as an employer.
- timing belts, waterpump everything new

Lets skip to the thing ... Before i did this evrything, as i said... because oil and blue smoke, the car, as far as i know its not mapped yet, but anyway , with k&n airfilter, empty pre-cat, and ktec exhaust.... the car did great job on LOW revs, as the hava that flat spot..... When i drove in to the hills, there was that low power under 1500k revs... When i reached the line of 1500k the car did realy pull, great power, realy, had nothing to say about that "flat spot" i did feel great..

Now the car runs perfectly, idle perfect, no blue smoke, no DTC on Clip on ecu120.. great... BUT... here is the BUT ...

Now the car doesent get that power on 1500k, ist maybe on 2700-3000k , i feel much more power to the hill now, than before fixing everything.. but on low revs.. now looks like that flat spot or wha.. i realy dont know.... and on full throtle it like wants to go, and doesend want to go... unitl 3000k.. an normal throtle if you slowly put revs on.. its normal..

The timing is perfect, used EOM Mot. tools for timing.. the locking tool fits in perfectly to cams. i realy did a lot of timing on Renaults, and i think i did it perfect..

Today, i did get a new Vvt selenoid to worshop.. ordered on Thuesday, today came directly from France, our warehouseman or parts seller guy called me... come to the shop its here so i drove there, had realy good felling that its the valve, switched... still the same... DAMN...

I did checked the injectors and i did switched the Throttle Body with new one, since we had one in the shop, still the same..

Now i hope if you guys can help me with any ideas....

Im thinking now to replace the vvt pulley if there is anything wrong.. itst not loud on star like the corrupted ones are.. it just works, but i really dont know if it should be replaced every 5 years or 120k like timing belts.. now im realy thinking of replacing it just to see if that it.. damn..

Everyone would say, do a remap it will fix it... maybe it will, i dont know.... BUT i would like that, this revs and car would have the same power from 1500k up , like it had before i was fixing it, before i had only 10bars of compression on cylinders, now it fell that the car is realy stronger than before... but... why not on low revs if now compression is much better.. dont know anymore..

If you had any great idea.. i would be thankfull.. and sorry for long text..

Regards,
Simi

 

[Foxspeed]

it may sound daft but with it burning a lot of oil the cat isnt choked up with carbon/burnt oil is it?

 

[SimiRockStar]

so... you think that the cat could be choked? would have loss of power on high revs to... what do you think?

i have a decat pipe in a garage... could try to remove cat for a test drive...

 

[turkie172]

The Lambdas must also need looked at with mileage, age and oil damage

 

[NickD]

I would change THIS before getting too concerned.

 

[turkie172]

If your a Renault mechanic then use the Clip diagnostic to check fueling and you can run a CAT regeneration test

 

[SimiRockStar]

Oky.. lambdas are new.. both.. changed last year.. they work great on clip, uper lambda is changing mV like it should and second one after cat is the same all the time in mV..

I did had in mind to do some graph recordings at work.. to see where is the problem..

I will try, tomorrow, between the break

@NickD - ive had in mind that little pressure sensor allready.. BUT.. since we dont have it at shop, the only way is to order it and buy it.. cant only Test it and returned it.. hehe.. its around 160€... its not cheap.... but.. i said.. i did spend enogh money on engine.. and now i said.. i will be spending till its not oky.. end! hehe

Im thankful that you all did realy respond to my post quickly.. thabk you again.. and sorry for my english grammar mistakes

 

[turkie172]

Are you in europe?

 

[SimiRockStar]

Yes.. Slovenia

 

[turkie172]

Sent you a message

 

[turkie172]

I'm in Northern Ireland we are at the moment still part of EU so I can buy parts from Europe without import duty and pay just the EU tax and the exchange rate is good as well.

 

[SimiRockStar]

I will let you know tomorrow from NewDialogys what is the price and where is located..maybe direct from storage in France, than is still 5 days to wait hh

 

[RSRowe]

If you’re certain it isn’t the timing, then my suggestion would be lambda.
I’ve seen this issue numerous times, always there is no engine light.

Maybe you could switch the sensors (if they are the same plug)

 

[SimiRockStar]

The timing is perfect.. i put hand in fire for that

I know that for a bad lambda i allways get engine light...
The plug is the same.. for upper and lower.. they are only 6months old.. but i cant say that they cant be broken anyway...

So today i ordered Air pressure sensor.. Did check the price on link that @turkie172 gave me... ant the price here was a little higher.. but anyway.. i will have it here tomorrow... fingerss crossed that it will fix the problem

 

[RSRowe]

I know that for a bad lambda i allways get engine light...
The plug is the same.. for upper and lower.. they are only 6months old.. but i cant say that they cant be broken anyway...

In which case, I would switch the sensors around and check to see how it runs.
We are essentially just guessing at the problem for now. At least this will cost you nothing but a little bit of time.

 

[SimiRockStar]

youre right.. i will try thatto.... like you said.. we are guessing tnx for help guys

 

[turkie172]

The only other thing that causes low performance and can be common is the cam sensor people have had problems with it with poor aceleration even the knock sensor if you cant get the car on a dyno or mapped you can only change sensors in hope of a fix. Or since you are in the dealership is reprograming the ECU which might zero out the fuel mapping (long and short term trim) from the oil burning engine before repair. But it could all be the exhaust modifications and mapping or fit standard exhaust is the only answer you are in the right country for an Akrapovič exhaust they are made there and dont need mapped.

 

[SimiRockStar]

A little update :

Status : still not solved..

- Oky.. have replaced vvt valve.. tryed function to enable vvt on Clip with 5w bulb.. did light up..so, the signal came, i think there is no need to check wiring with multimeter.
- did cahange the lambdas, still the same
- replaced Air pressure sensor , it was glued up for 5years, because i broke it.. .. and looks like it was working, coz nothing changed with new one.. bot oky.. its replaced and no more glued
- today i removed main cat, it was not choked, could see the light through..
- installed de-cat pipe for a test... works the same..
- yesterday at work, tryed reprog. on ecu 120, couldn do it.. got some R-somenumber error that cannot do the reprog.

Now i need to try the knock sensor like @turkie172 said. About exhaus modification... 5years agor when i empty the pre-cat.. as i didnt know what will it do.. the power was lost... realy lost... like 1.6 16v ... when i changed the exgaust with K-tec... it realy did the magic.. and the car went much better that before with pre-cat and original exhaust... so the exhaust is not making problems.. Would install Akrapovič on when i wass buying exhaust.. but ther were non in stock at that time.. but anyway.. i was an i still am very satisfied with the K-tec one..

Dont know where could i go wrong since this is happening after the engine "rebuild" . Did check today for any leaks.. .. and after 650km.. whole engine dry.. good sign..

So.. next step like i said.. knock sensor..

Since we are guessing.... what about that damn Dephaser pully.. its not rattling or anything... could it be broken even if there is no rattling sound like the broken ones sound?

Did notice something... as i went home from work yesterday at 18:00pm, it was -4°C outside, and two cans of beer destroyed.. i had i feeling that was going better on lower revs.. now i dont know ...was that -4 or two beers, coz today is 7° and no beer and does not go under 3000k

 

[turkie172]

Well then by the sound of things your ECU maybe locked because someone programed/ mapped it and that’s why the car is not running right I would work on the ECU it should accept reprograming or it is faulty.

Clio 197 / 200 / Megane 225 / R26 factory restore of ECU (unlock)