16v Holding Back / Poor Performance

[The Ships Cat]

Hi All,
Have been having trouble with R19 16v M reg 70,000 miles.

Problems seem to be as if the engine has lost it's edge , is holding back a bit, and is not as responsive at high revs as it used to be. I have also noted that it has developed an intermittant fault where the revs will drop and the engine will splutter , but it then recovers ok . I have not used Tesco fuel.

Over the past few months the following have been replaced . Plugs / Distributer Cap and Rotor Arm / Plug Leads / HT Coil / TDC Sensor / Lambda Sensor / Center section of Exhaust and Fuel Filter.

At the weekend I cleaned the Throttle Body , It was dirty , noted that the idle screw had been buggered about with and had been screwed fully home , everything is now cleaned and the idle screw is about 3/4 of a turn out , tickover ok. As the idle screw had been messed with I am wondering if the Throttle Position Sensor may have been "tweeked" , is there any way of checking this, such as checking the resistance of the pot in relation to the flap?

I also cleaned the idle valve , this was clean to start with , and moving free.

Have metered the CTS and it appears ok , does this sound like it could be a CTS problem?

The only other problem that I have is that the alternator needs replacing. It is charging the battery ok but the battery light is glowing dimley when the engine is running. Could this be contributing to the problem ?

Any pointers on this problem would be much appreciated.

Regards

The Ships Cat

 

[bbracer16valver]

screw fully home or a start ALL THE WAY IN

the tps could of been messed with but you say it was fine

me i would check the wires on the tps the three on top, see if there naff then change it, also if you can get one cheap change the iggy modual aswell

 

[The Ships Cat]

Thanks for the prompt reply bbracer
I queried the idle screw position as in the tech article in mentioned unscrewing 2 turns as a start position , will try again.
I do not know if the tps is in the correct position , I have not moved it , I am thinking about marking the present position and trying moving it about 2mm either side of original position.
Anyone any ideal what would be effect if tps is in wrong position ??
The ignition module has been changed.

 

[hooverphonique]

engine earth problem?

 

[Chris H]

erm what tech article? it says don't touch them and it shoudl be fully screwed in.

how have you metered the CTS? Using an ocsiliscope? if so where there any drop outs, you need to set the refresh rate at a max of a few ms to catch a glitch

 

[The Ships Cat]

Hi Chris
Thanks for the reply, When I was cleaning the throttle body and found anti tamper cap removed thought I would check how far screw was wound in as a reference.

In the article it refered to the plate bypass screw , and unscrewing it two turns as a starting point ,is this the same as the idle screw?

The plate bypass screw. If it's been messed with then remove it and clean the channel out with cleaner and a cotton bud. Screw it back in right the way in. Undo it two turns.

I metered the CTS using my works scope , seemed ok but have got one on order from GFS , about a tenner so its worth it to eliminate it.

 

[Chris H]

hmm I will check ther article later.

I normally remove the screw if its been tampered with and clean it out throuroughly then screw it right back in thats where its meant to be.

check air inlet temp sensor as well, its on the offside end of the inlet manifold, same pluig as the cts.

What abotu basics, oil, plugs etc? What plugs are you running? Changed the fuel filter?

 

[bidderman1969]

I normally remove the screw if its been tampered with and clean it out throuroughly then screw it right back in thats where its meant to be.


just a query, what is the point of that screw anyway, as in why is it there? sorry to sound thick like :?

 

[Chris H]

for cars with no icv its there to bypass the throttle plate to allow it to idle.

 

[bidderman1969]

ah, just thought i'd ask

 

[The Ships Cat]

Thanks for replies , I did not think of air temp sensor , will give that a check, the oil was changed about 3,000 miles ago , the plugs , leads, dizzy cap ,rotor arm and the fuel filter about 1,000 , can not remember plugs fitted but they were bought from Renault and the ones that Renault recommended

Is there any advice on the best plugs to use or ones to avoid ?

Is there any way to check the throttle position sensor ? I have not moved it , what would be the effect if it was in the wrong position ?

Thanks for any advice

 

[bbracer16valver]

use standard plugs single electrode