40 replies to this topic

[Sprocket]

Whats happening with yours?

I haven't mentioned it before as I asume that you would check these first( :nugget: Assumption is the muther of all @#$& ups)

Check all the basics, HT leads, spark plugs gapped, dizzy cap and rotor arm are all in good serviceble condition, then check the vacuum pipes for splits. If these parts are of an unknown age/ condition and have not been changed recently, then they are fairly cheep to replace, then these are eliminated, though it can be uneconomical to throw parts at the engine unless they are suspect.

If this has still not rectified the problem, then look at the injection system. as above.

I've found that if the diagnostic shows no fault, the mechanic will do nothing. Because its electronic and people don't understand how the system controls the fueling and ignition, particularly the mechanic( not all, but it's more often than not these days), they believe what the computer tells them and if it says its ok, well then it must be, ha, how wrong can they be. Sensors can be out of calibration but not faulty, throttle linkages can be stiff and the PTC heater can be open circuit yet the ECU fill not think there is a fault. If the ECU was a person you would say it was a bit thick yet it's supposed to be this all singing and dancing computer that controls everything and tells you everything. how many people know there is an electric heater in the bottom of the inlet manifold?

I bought my own diagnostic as I do not trust a mechanic to find the problem. The mentality of most mechanics is that if you are going to them for help then you know less than them, which is not always the case( what was that advert on tv recently where the guy said that if people don't know whats wrong with the engine and get ripped of then its not his problem) but you have to go to them as they have the expensive tools to tell them that the engine is running fine when it clearly is not

How do I pin a post, I think I shall write a topic on what to check on SPI systems running rough. Though I am no expert and not a mechanic, I have gathered a great deal of knowledge trying to fix mine, so if I can help then I will.

[Sprocket]

Not sure how much Rover are charging, but they have tried lots of different parts only charging if the new part works.

When you finaly get to the bottom of the problem then post it up, the symptoms the actual fault and how to correct it. The more information that is documented the easier it will become for others to fix theirs through the tears of others

[Sprocket]

Oh and there was something else. The original SPI back in 1992, the first few off the production were having warranty claims due to bad running at both idle and driving conditions. The resulting find was the vacuum capilary from the manifold to the ECU was full of fuel, this locked up the reading of the MAP ( Manifold Absolute Pressure) sensor causing in extreme cases a backfire into the inlet as the ignition advance was WAY out. The fix was to fit a fuel trap before the ECU and to remove fuel from the MAP sensor is use a piece of cotton wool pulled and twisted thin, inserted into the connection and the whole ECU left on a warm rad over night. Subsedquent engines were fitted with the fuel trap.

I got this from a guy that worked at the factory. I didn't know the guy so take the information as you wish, but will say that even with the fuel trap I suffered this problem.

Oh and change the oxygen sensor

[ruby mini]

Rover have now told us that they will check the timimg chain tomorrow as it is sometimes back firing through the injection system, the exhaust is getting very hot. If that is not the prob we will bring it back home tomorrow.

We were also told to try taking the CAT off and using a link pipe as the CAT may have collapsed..

[ruby mini]

Will keep you posted on what happens tomorrow with Rover.

[Sprocket]

Rover have now told us that they will check the timimg chain tomorrow as it is sometimes back firing through the injection system

You have read the post above the post above the post above

[ruby mini]

Have tried oxygen sensor, Lamdba sensor, replays, cleaned the injection system, new crankshaft sensor. But it still idles erratically and back fires

[ruby mini]

oophs forgot to mention also changed charcoal cannister and fuel trap

[Sprocket]

No No the bit about it back firing into the inlet manifold

[ruby mini]

will try cleaning this tomorrow

[Sprocket]

and I forgot to mention that if the fuel is still in the ECU and capilaries, then changing the fuel trap will do nothing

[ruby mini]

hopefully try this tomorrow. will keep you posted

[Sprocket]

http://www.ilexa.co....pic,6894.0.html

[AlexM]

Ruby Mini How many miles has your car done?

I think I shall write a topic on what to check on SPI systems running rough

An Excellent Idea Mini Sprocket!

[ruby mini]

mini has done 97,000 but is in excellent condition.
head been skimmed and new gasket fitted. i have had the car since 60,000 miles (4 years)
spoke to Rover today and they have now found a fault on the ecu, too much vacum going through should be 20 but trying to run at 40. they are trying to find out if they can bypass it.