Rover 200 & 400 Owners Club

W-2000 Rover 25 1.4 iS

Hi All,

Ok, well, this is now annoying me in a HUGE way...... I've started a new thread with all the information that I have and in the order that I have it.

New Plugs
New Leads
New Coils
New Temp coolant sensor
Cleaned TB with brake and carb cleaners (and pipes)
Checked for air leaks on vacume pipes
Unplugged IACV
Unplugged TPS (see below)
Even checked to see if IMG was leaking...
Generally, No change, when cold the car will:-

Start ok
Drive for half mile ok
Then begin to drive with no power
Somtimes (rare) backfire BUT with popping noise in the Inlet manifold
ONLY way to stop it while driving:-
Get the revvs UP as high as possible and the car will cure itself. The car will pass "through" the fault and sometimes clear and be fine
Car is better when warm but sometimes will begin to hunt while warm, then it is also undrivable.
I can't get to a Diagnostic untill at least Friday, the car NEEDS to be used for the daily commute. She's a brilliant little car with a lovley sounding engine, very healthy apart from this issue.

Ok, I know I needed to get more information so read on as to what I did next.

Tonight, when the car was stone cold I started it and went for a drive. I got 1/2 mile down the road when the fault began.


While it was juddering/power loss, I pulled over under a lamp post (trying to ensure the fault remained) and began to unplug various things.


My results were:- (remembering the issue was happening at this time)
IACV unplugged ----> No Change, engine still hunting, now drivable power --- Plugged back in!
TPS Unplugged ----> Engine went to 1300 Revs with no issue, as soon as you touch the throttle the revvs came back down and the hunting came back.
TPS Plugged back in ----> Revvs dropped and came to "norm" and hunting began again.
MAP Sensor unplugged ----> Engine tried to stall but good recovery and hunting still there.
When the engine hunts, you can't drive it unless you really stomp on the throttle.

I also did the TPS reset routine. Upon restart the revves went to 1500 for a short moment and settled --- Back to hunting again.

I have an MGZS 1,8 and when it had a missfire I put NGK plugs in and away it went....! This is not the case with teh 25..

I'm out of ideas... I bought an inlet maifold from the bay which seems to have everything still attached (well it does I asked the seller) the item number is 270663934618.

I bought this before I thought what the fault could be, it meant that I have a spare set of sensors, injectors and the manifold.

Has anyone got any fresh ideas so far? (Apart from get the car on the machine?)

Cheers people, sorry for the loooong thread, this is my only place for some real decent information.

John & Louise

is the catalytic converter ok. may have broken up inside and then causing the engine to choke up. i know its not too common but maybe worth trying the cat from your zs

Cat known ok!

We used to have this issue on our old 214Sli.

Turned out to be a corroded fuel pump connection. It was an absolute swine to trace.

As the car/connector warmed up it went intermittant causing a lean mixture and various issues. If you managed to drive it through this issue (usually using high revs), then it'd be fine for the rest of the day.

I tried everything to fix it, and in the end it was a grubby connection.

Try swapping the fuel pump relay with another one out of the fuse box. If this cures the issue then you've found a fault.

If not try unplugging the lambda sensor temporarily. If the fault goes away it is either the sensor or a fault somewhere with the closed loop fuelling control. You can unplug it from cold as it isn't used then anyway. Drive and see if the problem occurs. If it doesn't then at least you've narrowed it down a bit.

The older cars had very few diagnostics, so hopefully as yours is more modern it may be easier to locate the issue.

I have a fella comming this eve (really nice guy) for a mininal fee to check thr car over with his T4. He'll also do a "live" check?... So, my tak is to get the car in to the faulty state!!!!!