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Discussion Starter · #1 ·
My turbo has been hesitating for a while now, its boosting ok, has new plugs, dizzy cap, rotor arm, fuel filter, oil, water and air filter. Its now reluctant to start and is hesitating more than ever, it also has a lumpy idle, but not massivly so ( varies a 100 revs or so). Its worse when accelerating in a low gear, or if changing down, but its fine and smooth when in a high gear at speed, such as when on the motorway. Anyone any ideas as to why it maybe doing that?
The MAP sensor line is clear, it seems to heat up properly and the revs drop when warm like it should, so i dont think the CTS is faulty.
 

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Hi, Have you taken the plugs out lately and if so what colour were they. If they are black I had the same problem. I found out the unipart plugs fitted as standard did not have the self cleaning nose. I looked at the parts list and found an NGK set listed as standard rover fitment but they had the projected self cleaning nose. I fitted these and never had the problem ever again. Sorry I dont remember the part number but as I say it was on the rover micro fiche.

Regards Gary :)
 

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Discussion Starter · #4 ·
The car was fine a few weeks ago, its come on all of a sudden. Im using NGK plugs now, it had Champians in when i got the car.
The plugs are a bit black, but not oily, just black, its using a lot of fuel as well, about 20mpg, but it was like that before really, well, say about 24mpg before. Maybe a sensor has failed ?
Its better when cold, it feels about 90% ok then, but when warm it can feel really flat at times.
 

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youre consumption sounds quite good actually for a 2litre t. wouldnt say its a sensor fault really
 

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Discussion Starter · #6 ·
Possibly HT lead or coil problem? Coils seem hard to find though and i bet a dealer would want a small fortune for one.
 
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Phil_216sli_Mk3 said:
youre consumption sounds quite good actually for a 2litre t.
Not sure about that - our 820 Vitesse gives over 30 on a run.

If it's burning too much fuel, try changing the ECU coolant senosr (the one with the brown plug on the thermostat housing) in case it is telling the ECU that the car is cold.

About £6 from a specialist or motor factor.
 

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perhaps, depends how u drive it guess. My 216 will do anything between 23-38 depending on how i drive it.
 

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Discussion Starter · #9 ·
Ive never had 30 MPG out of any of my cars (see list in sig) thats gives you an idea of how i drive!!
I think the CTS is ok, i tested it with a multimeter, it gives the right resistance at the right temps.
 

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I dont suppose it started since the plug change? I think the NGK plugs that I used were quite special I dont recall the number but I think the number has to have P in it for projected self cleaning nose as in BPR7ES as apposed to B7ES etc.

Cheers Gary :)
 

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Discussion Starter · #11 ·
Just been for a run this morning. She started missing like mad, in fact up a long hill near exeter while trying to keep up with a monaro i only just kept ahead of a VW diesel vanette!
Ive now changed the HT leads except for the coil lead (i cant find a suitable one), ive changed the plugs for Champian EON2 platinums and ive cleaned the contacts on all the sensors i can get to with electrical contact cleaner.

I started her up and she missed like hell then it stopped and settled down ok. She isnt missing now although im not convinced she has full power.
 

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chrismm27 said:
Just been for a run this morning. She started missing like mad, in fact up a long hill near exeter
Hi, just thinking about this situation, this is a bit different to the symptoms in your first post as this time its misfiring when you drive it hard under load which makes me wonder if it is sticking valves causing the misfire.

Regards Gary :)
 

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Discussion Starter · #13 ·
That was just the worst of the misfire, it was missing pretty much all the time really. It wasnt a regular misfire either, but completely random.
Would sticking valves come on all of a sudden and after 13 years? It was running perfectly a month ago.
 

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chrismm27 said:
Would sticking valves come on all of a sudden and after 13 years? It was running perfectly a month ago.
Hi, I think sticking valves could start at any point in the engines liife, and often the engine has not missed a beat until then. I have experienced valve sticking quite a few times, It mostly comes on during warm up but can happen when hot, I noticed the more load that was on the engine the more likely it was to happen. The misfire that results from sticking valves is more of a soft misfire the engine feels rough and uneven and can gradually lose power nearly to a point of grinding to a halt. One thing it never is is violent like jerking you back and forth in the seat if you get what I mean. Has it ever stalled after a misfiring session and been hard to start?

Regards gary :)
 

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Discussion Starter · #15 ·
Its only ever been hard to start from cold, never when warm, but it has stalled a few times when hot, when dipping the clutch. This was before it started misfiring and its doesnt do it now. Originally i thought that might be stepper motor trouble or throttle sensor trouble.

Is there anything i can do to unglue sticking valves other than fitting new ones? If so it might be worth trying whether they are sticking or not.

I still think its an electrical rather than mechanical problem.
 

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Have you done a compression test?

Also, what are the emissions like on it? Sounds like you have done most of the ignition side of the system.

I know you say the MAP line is clean, but do you know the MAP sensor is OK? Also have you checked for vacuum leaks? Especially on the line that goes to the wastegate and the dump valve, can perish due to heat).

Also check the dump valve diaphragm is OK. An air leak anywhere means the MAP reading is incorrect and the car will run rough as MAP is fundemental to the ignition and fuelling. - The intake system and all lines coming off it must be 100% airtight.
 

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chrismm27 said:
Is there anything i can do to unglue sticking valves other than fitting new ones? If so it might be worth trying whether they are sticking or not.
I still think its an electrical rather than mechanical problem.
There is nothing that is 100% other than fit new carbon break valves, but
I have had some success by using forte engine flush and gas and injector cleaner if it is still available, Rover dealers used to have equipment to clean injectors and the valves with the inj cleaner and gas treatment, but I suppose you could introduce the liquids through the manifold then flush and change the oil. It could be worth it although it might cost £40 and not help matters.

Can you say that the misfire is really a hard cut or is it soft like I tried to describe (perhaps too badly)
 

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I'm thinking - is there an exhaust/valve cleaner that you spray into the inlet manifold and then turn the engine over (without the king lead attached) so that the cleaner is then pumped through the outlet valve and hopefully breaking down the dirt/crud???

You know, something really potent, like brake cleaner or maybe even a petrol/oil/diesel based substance???

Only possible downside to that would be petrol heading towards the cat and whatever you spray in not being good for the cat either (although that could be avoidable). Maybe even the unburnt petrol itself would be corrosive and lubricating enough to remove some of the crud and solve the problem.
OK, sounds a bit outlandish but I think is a practical suggestion.
 

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Discussion Starter · #19 ·
Ive done some research on the sticking valves and i really cant see it being that. It happens mostly to cars never raced, my car is never NOT being raced and my average journey is 20 miles! I use redex all the time, have injected it directly into the cylinders and into the inlet tract. It had a replacement valve last year.
My current favourite culprit is the cam sensor, ill try disconnecting it tomorrow, if things arent much worse its probably that.

The misfire has gone (after changing the HT leads), it just feels flat now, like it did last week.
 

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Discussion Starter · #20 ·
Matt Hicks said:
Have you done a compression test?

Also, what are the emissions like on it? Sounds like you have done most of the ignition side of the system.

I know you say the MAP line is clean, but do you know the MAP sensor is OK? Also have you checked for vacuum leaks? Especially on the line that goes to the wastegate and the dump valve, can perish due to heat).

Also check the dump valve diaphragm is OK. An air leak anywhere means the MAP reading is incorrect and the car will run rough as MAP is fundemental to the ignition and fuelling. - The intake system and all lines coming off it must be 100% airtight.
If i cant sort it this weekend ill get it emissions checked next week, ill see about a compression test as well. The MAP is ok and the line is clear, if i disconnect the line the car runs badly at ldle. The car is boosting fine and all lines are tight. I do have a GBE boost controller fitted and its working ok.
 
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