Hello from Fife

Hi,
Just joined as recently purchased a 98 MGF Abingdon vvc at just over 61000 miles

 

Great resources here!  

Picked the car up from Yorkshire and after a few checks, drove back to Fife without missing a beat.  Been in storage more or less since 2016 (less than 1000 miles since Aug 2016) and has had some recommission work done.  I've got a pile of MOTs and service history with it and the car is pretty much original Abingdon from what I can tell.  We've added around 400 miles (including the 250 mile trip home) in the last 3 weeks and have been really enjoying it, but of course expecting something to go wrong....

All has been fine until yesterday when we lost pulling power above 3000 revs.

Car easily will get up to 5000rpm and sounds absolutely fine out of gear, but in any gear I can't get above 3000 and above 2500 it is a bit lumpy.
As part of the recommission I can see receipts for oil and filter, plugs, but no filter changes!
We've also noticed a metallic rattle on uphill right handers for a couple of days (collapsing Cat?).
Thought we'd start with fuel and air and also look at exhaust - Cat and silencer were apparently done fairly recently although there are no receipts for it in the file, but they look almost brand new.

I have a new fuel and air filter on the way to start with, but if anyone has any thoughts, I'd appreciate an idea of where to start looking.

Head gasket (and cambelt) was done only 3500 miles ago although that was in 2015 - it was caught on a compression test.  I intend to do the cambelt as a matter of course shortly.

Cheers for now

Chris
 

G'day and welcome to The-T-Bar forum, we have a check list that is helpful to new owners and members:  https://www.the-t-bar.com/forum/54-how-tos/99326-a-check-list-for-new-owners  it isn't going to address your current problem but may help with other concerns.
Now to your current hassle, you don't say as to which engine you have, MPI or VVC. This is important as VVC engines have a bit of extra complication going on.
However  your  thoughts of a failing cat converter are a possibility but there are more likely culprits. 
For now however I will assume that you have an MPI running a MEMS 1.9 ECU. 
Do you have access to a OBD diagnostic unit for these cars?
Only the factory T4 Testbook or a Pscan will be able to do a diagnostic reading of these early cars.
This may or may not show your problem by throwing up an error code.
However there are limitations as the designers of the car didn't foresee all likely problems and the ECU  doesn't record all possible faults that is not to say the OBD scanners aren't a useful tool, they are a very powerful diagnostic tool but there are limitations, they are not crystal balls!
I do suggest you get a Pscan unit, you will find all you need to know about them here:  https://www.the-t-bar.com/forum/pscan-uk-diagnostic-tool-forum  
Now other possibilities for your problem are ignition, breaking down under load is a classical symptom of ignition system problems, check the HT leads, dizzy cap, rotor arm, and coil. then check your fuel filter isn't blocked. Also check you cam belt timing is correct.
Once you've gotten this far get back to us with your findings and we'll go from there. We will get to the bottom of this!
 

Thanks for the welcome and quick response.  I've seen the checklist - very helpful and in line with my initial thoughts as to what to get done.

Apologies - I should have been clearer in my post - engine is a VVT, so running MEMS 2J.

Will add ignition to the checks already on the way.  Fuel filter was my first thought just simply as the car has been laid up for so long.  We're about halfway down the second tank of petrol now so may be some crud gone through.

Was planning on getting the Pscan but had thought to leave it until this is sorted as no engine warning lights on so assumed there would be no error messages - is it possible there will be something to read/diagnose even without a light on?

Cheers

Chris

 

The pscan will show problems that wont show idiot lights. 
I don't have a VVC engine so no practical experience on them. how ever there are plenty here who do and I'm sure they will weigh in with sage advice before long.
I do recall something similar happened to a members VVC engine in the dark distant past, but I don't recall what. But it wouldn't rev out too.

 

ChrisGfife
As with Cobber, I do not have personal experience of VVC engines, but I DO recall seeing several conversations about VVCs with similar problems.
Take a look at:

https://www.the-t-bar.com/forum/21-david-aiketgate-s-guides/97721-vvc-electrical-plugs-5500-rev-limit#197220

I found that post by using  the Search facility, which can be found by clicking on the word Search, to be found at the top right of this page.  It's next to the "Donate" button, you might decide to pay that button a visit if david-aiketgate's post solves your problem.

Fuel Filter would have been my first guess on an MPi engine, but it could/will cause a power limit problem on any engine.

Good luck with the fix.  You are doing the right thing consulting this resource.  It has helped me a lot in the past, and undoubtedly will many times in the future!

So quick update on today's progress:
Changed the fuel filter and air filter.  Air filter was filthy so not been changed in a while I'd think.  Had a good look round the engine bay and nothing looks out of place.  Checked the wire connectors as David's post linked by EllisoJo (thanks) but all ok, plus was running fine until Thursday and I'd not touched anything prior to that!

Unfortunately this has not solved my problem.  I thought it had as I pulled off for a test drive as the car pulled away quite well, but as soon as it warmed up the pulling problem re-occurred.  Definitely sounding a bit lumpy now too at anything approaching 3000rpm.  Still a bit wary of the Cat after the metallic rattling but it looks good from the outside!
 

Pscan on the way also.

All thoughts appreciated

Cheers

Chris

Welcome.

One thing to try would be to see if the cat or exhaust have become blocked. People have experienced this in the past with similar symtoms

The best way to determine a blocked exhaust is to measure the exhaust pressure it should be low like 2 psi unfortunately exhaust pressure testing gauges are a very rare piece of equipment, as for some strange reason the never caught on.  But as you say typical symptoms are that it starts Ok and bogs down from there.
A cat that has the media breaking up can block the muffler downstream so just replacing the cat may not solve the problem.
 

One possibility that springs to mind is a failed engine temp sensor.  This could cause overfuelling when the engine warms up, as the ecu thinks the engine is still cold. 

Thanks for the welcomes and the comments so far.

Been a bit busy the last couple of days but PScan arrived today, so this evening I downloaded the software and plugged it in.  After wiping the historical error codes I only got one recuring error which was the Engine Coolant Temp Sensor.  The live data showed 90deg reading even from cold and did not move at all as engine warmed up.  David, presumably this is the engine temp sensor that you refer to?  My car is a 98 Abingdon VVC so I think I need the brown one, but struggling to identify which one that is on Rimmer or MGOS spares websites.  Can anyone give me a part number!!!

The dash water temp gauge however is working apparently fine, so presumably fed from somewhere different? 

Still a little suspicious of the Cat too but a failed ECT sensor would certainly not help things!  I'll check the old one with a multi meter once I swap them.

Cheers

Chris 

And then I found the "Coolant Sensor Confusion" thread from 10 months ago which makes it clear that I need the MEK100060 sensor (my VIN is 038729), so I've ordered one to swap in and see what occurs...

Chris

Sorry to throw a question in but my cat doesnt look like that, there is one on Rimmers like that but it says aftermarket. Mine doesnt have the ribs.