Further to my post in the wrong section I have now changed plugs, air filter, oil, oil filter but the car is still not quite right. It starts and idles fine but feels hesitant, and a bit gutless for a 2.5 litre engine, seems to pulse under acceleration, cruises OK once up to speed. Considering the throttle body clean and reset process but a bit reluctant as it idles normally. Engine earth seems OK
Is it possible for the throttle position sensor to be problematic without a ecu fault code? Is there a way of cleaning the throttle body without complete removal and reset procedure?

Thanks

Hi,

If you are reluctant to remove the throttle body, you can use something like Holts EGR & Carb cleaner and spray it into the throttle body. Removing it would be best and it's not a complicated job. The gears can also stick that control the valve, so removing the cover and checking they can move freely, removing any rust on the shaft and lubricating them is a good idea.

It is possible to have an issue with the accelerator, without a fault code, but I'd check that the throttle body is clean and can respond appropriately first.

In relation to the QR25DE as mentioned in the other thread, the IVTC solenoid should also be checked, the timing chain isn't worn, by measuring the tensioner is less than 10mm (link here viewtopic.php?f=15&t=46762 )and pre November 2003 QR25DE had an issue with the cat and precat failing which was corrected after that date. viewtopic.php?f=15&t=46921&

Can you elaborate on what you mean by pulse? Does the rev counter jump or do you put your foot down, revs go up, but no linear response, or a delay in delivery. Perhaps you have a clutch/flywheel issue?

Kind regards,

Eoin

Thanks for the reply Eoin

I will take the throttle body off to clean it and check the gears etc in the week. The pulsing sensation is under acceleration as if the engine is being held back, just doesn't rev cleanly and smoothly under load. Looks like it probably has the self destructive cat as well, what's the best action to take with that to prevent issues?

Hi, we have the same car :)

I've just spent all day on mine... Alternator off, 5 bolts off holding exhaust to engine, 2 bolts under the car too, both 02 sensors off.
Screw driver the CAT and smash the guts of it to pieces, get every little price of material out, wash/dry it, put it back together with a new exhaust manafold gasket.. Only re-plug the top O2 sensor back in.

Find a nut and bolt threaded the same as an O2 sensor, screw the bolt into the empty bottom hole of your now hollow cat.

Drill a hole behind the second CAT (further down the exhaust), weld the nut to it, screw 2nd O2 sensor in with extended wire.

CAT gone, emissions pass, EML out.

All done on a day.. Piece of mind plus plus

Also... Mine has a very subtle hesitation on acceleration too, doesn't really bother me, but will Check chain and TB later!!

Have you lock-tightened your butterfly screws?

https://www.youtube.com/watch?v=-G7sDuIOb8g


THATS A MUST!

Sorry for high jacking..

Eoin, in your post above there's a link to a pic with a ruler and the cam tensioner.. I'm not really sure what I'm looking at or infact where to measure from.. Could you tell me how many mms you are seeing in the picture?

Then il figure out where to measure from

Thanks bud

Low

Hi Low,

Allowing for the fact that the photon is taken to the side from an angle as opposed to straight on and parallax error when readinf the ruler, I'd say the tensioner is extended at least 20mm.

I have edited the original image and attached a red line, illustrating the measurement. You are measuring the extension of the chrome shaft of the tensioner, from left to right.

Kind regards,

Eoin

Thankyou so much!! all is now clear.

Big appreciation
Low

Little update, found time to remove throttle body, drilled out rivets cleaned up centre sprocket shaft, seemed OK. Refitted cover with new rivets, cleaned throttle body as best I could refitted and now have high idle speed as well as poor performance. Tried the reset procedure but no joy. Next check is the earthing and a sneaky peak at timing chain tension. Might unbolt the cat to check for blockage ig it ever stops raining. Joy of joys.