Maestro 2.0i lack of power

[kodachromeII]

Hello all, my first post and i'm after some help :D.
Ever since driving a maestro van at work, way back in 1986, i've been hooked on maestros. Purchased my first D reg mg maestro in 1990, now on my 3rd MG Maestro. I'm after some help or guidence please, my car is running very lumpy, trying to accelerate on the motorway today, i struggled to reach 70mph. The engine is ticking over rough, spark plugs, leads, cap, arm all good. The tick over of the engine is almost like one of the spark plugs has failed. I had the same fault around 18 month ago, fault just cleared. Can anyone advise me what can possibly cause lack of power, rough running on a 2.0i maestro, (1991 with 60k on the clock ).

Many Thanks

Andy

[E_T_V]

Check/change the rotor arm as these can pack up. Also check the carbon brush in the cap is making a good contact.

Also look to see which plug is causing the misfire (it'll be a different colour) and change it to eliminate that as a possible cause.

[kodachromeII]

Check/change the rotor arm as these can pack up. Also check the carbon brush in the cap is making a good contact.

Also look to see which plug is causing the misfire (it'll be a different colour) and change it to eliminate that as a possible cause.


Hi, have change the plugs, and used a test glow thing that you put between leads and plugs, all appear to be firing correctly.

Thanks for the superfast reply. I'll change the arm as a precaution next

Cheers

[G51 NAV]

Try changing the leads as well.

[matthewsemple]

Welcome kodachromeII - are you a photography enthusiast or a Paul Simon fan?

[G Force]

Hi KodachromeII.

If you are satisfied that all the cylinders are sparking correctly, but you still have a misfire then the next step would be to do a compression test to check for the possibility of a valve problem.

If you had any bad snow recently and had to leave the car parked outside or drove it in deep snow, it would be a good idea to check the cambelt timing, because the timing can jump teeth if snow gets onto the belt. Does the timescale of the problem relate in any way to the inclement weather?

If the spark plug gap is less than 0.035in that will cause very rough idle and drivability but should not cause a severe lack of power like you describe.

[kodachromeII]

Welcome kodachromeII - are you a photography enthusiast or a Paul Simon fan?

Yeh, i dabble with photography :D

[kodachromeII]

Hi KodachromeII.

If you are satisfied that all the cylinders are sparking correctly, but you still have a misfire then the next step would be to do a compression test to check for the possibility of a valve problem.

If you had any bad snow recently and had to leave the car parked outside or drove it in deep snow, it would be a good idea to check the cambelt timing, because the timing can jump teeth if snow gets onto the belt. Does the timescale of the problem relate in any way to the inclement weather?

If the spark plug gap is less than 0.035in that will cause very rough idle and drivability but should not cause a severe lack of power like you describe.

Today have changed, leads, arm, cap, plugs ( again ), fuel filter. Trouble started on Sunday after a 100 mile round trip, left car for an hour, started engine, performed a 3 point turn, strange whinning noise came from the engine, ( assumed it was the power steering ), since then car has been lacking power and missing. Sounds like a dead spot when you rev the engine. Same thing happened 18-24 months ago and fault just cleared itself :banghead:

Car always garage stored, used approx once a week..

Thanks for all your replies :)

[Russ]

I had a simmilar problem a couple of years back which with help from GForce turned out to be a blocked fuel pick up pipe in the tank. My car hadnt been used much leading up to the fault. Had it steam cleaned and not used supermarket petrol since and has been ok (touch wood!)
Does the fuel pump sound a bit strained when running?

[G Force]

Trouble started on Sunday after a 100 mile round trip, left car for an hour, started engine, since then car has been lacking power and missing.

Sounds like a dead spot when you rev the engine. Same thing happened 18-24 months ago and fault just cleared itself :banghead:

:)

Hi

Just picking up on the circumstances that surrounded the start of your troubles, there is a possibility that the fuel rail temperature switch could have stuck in the hot position.

It would be worth just removing the two wires from the small switch in the centre of the fuel rail on top of the inlet manifold. Put them somewhere where they can't melt or short out on the engine and see if that makes any difference to the idle and drivability. If it does (I doubt we would be that lucky;) ) then the fuel temperature switch is faulty.

That is the sort of fault that could easily just right itself.

[kodachromeII]

Hi

Just picking up on the circumstances that surrounded the start of your troubles, there is a possibility that the fuel rail temperature switch could have stuck in the hot position.

It would be worth just removing the two wires from the small switch in the centre of the fuel rail on top of the inlet manifold. Put them somewhere where they can't melt or short out on the engine and see if that makes any difference to the idle and drivability. If it does (I doubt we would be that lucky;) ) then the fuel temperature switch is faulty.

That is the sort of fault that could easily just right itself.

Tried removing the wires, problem still there..

If i remove the spark plug lead nearest the arm, there is no change in the engine tick over, also if a remove the lead nearest the cam belt, again, no change in the engine tick over. Compression check being carried out tomorrow.

Experianced some very minor backfires today when pulling away in a low gear..:banghead:

I feel its an electrical problem, givens its intermitten nature

[G Force]

. Compression check being carried out tomorrow

Hi let us know the results of the compression test and then we can take it from there.:)

[kodachromeII]

Hi let us know the results of the compression test and then we can take it from there.:)

Hi, compression test fine, fault traced to injector nearest the cam belt. Are injectors still available new? First time i've ever experianced a deffective injector in 20 years of owning a maestro...

[G Force]

. Are injectors still available new? First time i've ever experianced a deffective injector in 20 years of owning a maestro...

Hi

Yes the injectors are still available, and you are quite right it is rare for an injector to fail completely. Glad you got to the bottom of it.:)

[kodachromeII]

Hi

Yes the injectors are still available, and you are quite right it is rare for an injector to fail completely. Glad you got to the bottom of it.:)

Thanks for all your help..