Won't rev

[Garfy]

Good afternoon folk 
Before I start delving into the issue,just testing to see if anyone has had the issue before.

Noticed on way home from shindig, Maureen doesn't like revving anymore, was fine on the way down.

First gear up to around 6k, 2nd gear 5.5k, 3rd 5k and rest cruising around the 4.5k.

Acts as if it's hit the limiter and coughs a little.

This year have had a sports cat installed.
MAF mod.
New air filter swapped like for like cone filter.

All was working fine together before last weekend.

Works fine otherwise and no EML.

Any idea what the fault is indicative of?

Many thanks for any input,

Garfy 🙃

[Chilli Girl]

Damn, that's my fault because I said that Maureen looked really lovely with her sparkling new headlights.  I must've said something to upset her. Hope you get it sorted Garfy.

[Gaz mr-s]

I'll set aside my distaste for absurdly-named cars & suggest the crank position sensor.
Bottom of the timing cover, access from underneath, - quite awkward to get a spanner on. It has a wire & the bolt provides the earth connection. It could be corrosion. Mine had become loose...no idea why.

[jonbill]

did you fillup with petrol just before you got there or just after you left?

[Garfy]

I'll set aside my distaste for absurdly-named cars & suggest the crank position sensor.
Bottom of the timing cover, access from underneath, - quite awkward to get a spanner on. It has a wire & the bolt provides the earth connection. It could be corrosion. Mine had become loose...no idea why.

Thanks Gaz, will get that checked today.
I like absurd 
Named after a silver cat I adopted and became fond of, I didn't name the cat 

[Garfy]

did you fillup with petrol just before you got there or just after you left?

Good call Jonbill, I did fill up at a small Texaco garage on the way back 🤔 still got half a tank left tho.
May need a little unspirted driving today to use it up, then top up with some nice stuff, see if it makes a difference.

[Garfy]

I'll set aside my distaste for absurdly-named cars & suggest the crank position sensor.
Bottom of the timing cover, access from underneath, - quite awkward to get a spanner on. It has a wire & the bolt provides the earth connection. It could be corrosion. Mine had become loose...no idea why.

Nice one Gaz, it was indeed corroded, taken off and new bolt fitted, earth connection taken back to bare metal all put back together and connected up    (not by me    )
Unfortunately same issue 

Could it be the sensor itself?

Any other thoughts on the subject welcome

[Gaz mr-s]

Hmmm.... it was Carolyn's 1st thought too (I learned via her.)
Next to try is the maf....the sensor is hidden up, not the easily visible blob....spray it with carb cleaner or such. If that doesn't work gun it in 2nd gear & describe what it does....your top post is a little vague.

[Garfy]

I will take it out again today, see if I can get a video of issue. Also trying to set up torque to log the data. 😁

[Gaz mr-s]

A simple description should suffice....is it misfiring, how does it rev to sort of thing.

[Garfy]

Out in it at the moment, got the video don't know how to upload it 🙄

Seems to be slightly worse today, I'm going to describe 2nd gear as this is where you notice the most.

Accelerates fine to 4500 revs (5.5 the other day) then won't go any further, drops back to 4k, up again then back.

All other gears won't go above 4.5k

Whilst driving, I put the clutch in and floored accelerator, went up to 5k, then dropped down to 4k and bounced on the rev up and down from 4 to about 4.1

Hope that's a bit clearer.

[Gaz mr-s]

I don't know the answer, but what about car stationery... does it rev to 5k or more then?

[Gregmorse]

On the MK2's the Knock sensor would limit rev's but at alower RPM than your getting to, and it'd throw up an engine light...

[Garfy]

I don't know the answer, but what about car stationery... does it rev to 5k or more then?

Will drive to a secluded area and check. Don't want to annoy the neighbors 🤣

Someone has suggested adding another earth to the sensor, which should get done next week.

Thanks again everyone for the input

🙃

[Call the midlife!]

Could also be the crank position sensor but it's a long shot, bottom of timing chain cover but in the block itself. Similar idea to camshaft sensor.
Really does sound like a blocked cat though to be honest, even though you've smashed the precats heads in.

[Garfy]

Could also be the crank position sensor but it's a long shot, bottom of timing chain cover but in the block itself. Similar idea to camshaft sensor.
Really does sound like a blocked cat though to be honest, even though you've smashed the precats heads in.

Spoke to the mechanic, we're going to drop the cat and give it a blast, see if the problem goes.
Sports cat, brand new, only been on a couple of months.
Could it be possible it's the cat itself?

Morning ☀️ 😁

[Ardent]

Sports cat, brand new, only been on a couple of months.
Could it be possible it's the cat itself?

Be a simple test IF you had a spare to chuck on.
One of those cheap endoscope could also be handy.

[Garfy]

A little further information folk.
Been around a week since I drove her, driven to work this morning as the mechanic is coming out to have a look and it's slightly worse.

Won't now rev above 3.5 - 4k in any gear.

Thinking now, it couldn't be the earth to the crankshaft sensor as that can't get worse in this respect, could it?
Thinking it points more towards the cat being blocked as that could get worse, i.e. more blocked.

Got my old cat in the car to swap back and see how it is then, fingers crossed. 😊

[Chilli Girl]

Hi Garfy, Do hope Maureen's problem gets solved relatively cheaply and she'll be back running as she should soon.

[Topdownman]

I am no expert at all but I dont think it will be the cat, a sports cat has better flow than an oem so no real chance of it causing these symptoms so suddenly.

I have a different engine but I had problems a few years ago and a blocked cat was talked about as a possible problem.

I ended up with a new crank position sensor (the end was all corroded) and the fuel pump filter needing cleaning.

I would suggest just getting a new CPS as cheap

https://www.ebay.co.uk/itm/CrankShaft-Position-Sensor-Pulse-Crank-Shaft-60241-BREMI-for-Toyota/184201615918?fits=Car+Make%3AToyota%7CModel%3AMR+2%7CCars+Type%3A1.8+16V+VT-i%7CPlat_Gen%3AMK+III%7CCars+Year%3A2004%7CBodyStyle%3AConvertible%7CVariant%3AMK+III+%5B1999-2007%5D+Convertible%7CEngine%3A1794ccm+140HP+103KW+%28Petrol%29&hash=item2ae3459a2e:g:pq4AAOSwY~pecgCt

I would ask your mechanic to check the fuel filter rather than doing the cat.

As I say, no expert whatsoever, just my thoughts!

Good luck.

[Garfy]

Spoke with the manufacturer of the cat, he informed me, if it was blocked it wouldn't rev above idle, so didn't swap the cat.

Couldn't get the car on ramps to try a new earth on the crankshaft sensor. Too wet and kept sliding.

Backed out MAF mod and issue is still there.

Continue with trial and error next week, it's a little annoying driving in 5 o clock traffic with everything whizzing past you but at least I'm safe from the police at 70 mph tops. 😁

[Jamtastic]

Hi @Garfy

Did you manage to get Maureen sorted in the end? Sounds like a fuel pressure problem perhaps, especially as it's degrading. Filter or pump?

Hopefully you've got it fixed and I'm far too late with my 2 pence worth

[675Jim]

Another vote for fuel filter here. Cheap and easy to do. Worth a try.

[Garfy]

Not sorted yet, will be testing with my mechanic today 😁 got a spare MAF and coil pack to swap and try.
Will search on filter issues and rectification (that's a big word for a bank holiday 🤭 )

[Garfy]

So, we've swapped MAF, coil packs, spark plugs, made no difference    Checked the fuel filter currently checking vvti solenoid and cleaning which works ok. 😤🤔 Mechanic is a little stumped