13 replies to this topic

[Jackst150]

Hi everyone,

I'm new to the site, there seems to be a lot of talk on the spi systems and running problems, but thought I'd start a fresh and get some advice from everyone.

Here it is, my girlfriend and I have just purchased a mini 1.3i spi. It's a great looking car, had to do abit of welding to the door seals ect, it was sitting outside in a yard for 2 years!!

On failing the MOT on various bits such as rear brake shoes and ball joints, all was fixed but failed miserably on emissions, which was expected due to the massive amount of black smoke coming out the rear!

It had an aratic idle and when the engine got up to temp it couldn't cope and ended up cutting out all the time. I've followed various posts on why and in doing so have changed the lambda sensor, water temp sensor and repaired a vacuum pipe. It's now idling fine and revving how it should. But it is still over fueling and running very rich, still pours with black smoke!

Next I'm thinking of replacing the vacuum pipes and fuel trap. But I don't seem convinced as when I've taken them apart and inspected there seems to be no obvious signs of deterioration, and also sucked it both ends to prove its airtight and all seems how it should :/

The air box has to be sealed when fixed as when the air is drawn through the air box, that creates the vacuum in the red fuel trap line. Correct?

Can anyone offer any advice as to why it's over fuelling still? Or have I missed something out I should have replaced?


Cheers guys!!

[firstforward]

This will not help you much, but I had the same situation. The point is all these sensors have a mileage/age limitation and should be replaced at intervals. As a result I replaced everything and the parts came to something like £140.00, very little outlay for peace of mind and yes it cured my running problems. For me at the end of the day I found the fault was indeed a damaged vacuum hose joint near the bulkhead, it was the first thing I had inspected and had missed the hairline crack letting air in so that was my mistake.

 

It passed its second MOT on Friday since the replacement and the emission readings were first class. Now I appreciate if I had not changed everything that might still be the case but for how long? I really do not want to be chasing faults forever. If after changing everything and the fault still persists, then you at least know to look deeper than "serviceable parts".

 

Whether your situation is the same as mine, I cover approx 14-18K miles every year, if your mileage is much less you may not want to spend £140.00 in one hit.

[RedRuby]

As said it can pay to change all sensors and vacuum pipes for peace of mind, particularly when you do not know the cars full history. If it was me I would next change the fuel filter, located under the fuel tank on the rear subframe, the air inlet temperature sensor and the following vacuum pipes, inlet manifold to air box, inlet manifold to petrol trap and petrol trap to ECU. for all those you will probably pay about £40. If this does not fix the fault, at least you will have peace of mind that you have done a lot of the work required. It may also help if you put a post on here to ask if there is anyone reasonably close to you that has a code reader for an spI to help diagnose faults.

[Jackst150]

Well it's been sitting in a yard for 2 years, it's all okay except this 1 problem of over fuelling, iv replaced the sensors and it seems to be behaving better.

I've just been out to have another go. Starts fine straight away, runs and revs up fine with no problem except with the black smoke (over fuelling). I left it to warm up for 10mins, at which point it suddenly started to splutter and conked out. Started again fine, but spluttered and conked out again 20 secs after that!

So it's over fuelling all the time. But when it gets warm it can't handle it and gives up.

One thing I forgot to mention is when I took off the manifold to get to the lambda and water temp sensor I noticed a terminal lug on the underside of the manifold. It seemed to have a bit of corrosion damage to it, wether it had been corrosion from the elements or a short circuit I'm not sure, but I replaced the lug and reattached it. What is this for though? As if it is shorting then it could be a faulty sensor or whatever it's meant to be.

I'm going to order new vacuum pipes and bits to see if that helps as others have suggested! Other than that I'm not sure what else to do other than give it to my mechanic, or perhaps a mini expert. Help!!!!


Thanks and thanks firstfoward for your reply!

[Jackst150]

Cheers red ruby! I think I will do just that and order a fuel filter and vacuum lines. Iv replaced the air inlet temperature sensor too, along with sparks. I think I'm starting to get somewhere. I'll order the parts and keep the post running with my progress. Thanks again.

[rightlad]

Did you get your problem fixed

[spiguy]

What does your temperature gauge read when the car is warmed up?  Is it showing normal engine temperature, or is it staying at cold? Normal should be around the half way mark. From what you say I suspect the ECU is continuing to provide cold running fuelling even when the engine is warm. If so you should notice that the gauge is not reading correctly. If it is this, then this will be due either to a faulty coolant sensor, or more likely due to sitting, a lack of flow of coolant through the inlet manifold due to blockage. Even more likely if there has ever been any sort of radweld / stop leak additive put in the engine.

 

The terminal lug you found is for an electric manifold heater. It's designed to start heating the manifold as the engine warms up to give better cold running. Nice to have it working, but I ran my SPi for years without it and didn't really notice any difference. As soon as the engine starts to heat up it's effect is irrelevant, and I expect it is switched off at a certain coolant temperature.

[FlyingScot]

Did you get your problem fixed

Presume so it was nearly a year ago......

FS

[Badboytunes]

Sounds like the problem I just had

[Perrylawrence96]

I have a bad overfueling on my SPI, I have changed near on all sensors etc etc, it seems to be that the Stepper motor is faulty ( I think ) it its not stepping back at all.. don't know if this will help

 

 

Cheers

[spiguy]

 

Did you get your problem fixed

Presume so it was nearly a year ago......

FS

 

Doh! never noticed.....

[spiguy]

I have a bad overfueling on my SPI, I have changed near on all sensors etc etc, it seems to be that the Stepper motor is faulty ( I think ) it its not stepping back at all.. don't know if this will help

 

 

Cheers

The stepper motor only sets the idle position of the throttle, it wouldn't really affect fuelling when driving. What is your idle speed?  Are you saying that the pin driven by the stepper motor does not move at all? What happens when you switch off the ignition, do you not hear the stepper motor operating (like a high speed clicking sound). They can go faulty, commonly it is just dry / broken solder joints on the circuit board inside the housing. It's not too hard a job to remove the stepper motor unit and open up the housing, then you can have a look and see if any of the solder joints are broken,

[Perrylawrence96]

 

I have a bad overfueling on my SPI, I have changed near on all sensors etc etc, it seems to be that the Stepper motor is faulty ( I think ) it its not stepping back at all.. don't know if this will help

 

 

Cheers

The stepper motor only sets the idle position of the throttle, it wouldn't really affect fuelling when driving. What is your idle speed?  Are you saying that the pin driven by the stepper motor does not move at all? What happens when you switch off the ignition, do you not hear the stepper motor operating (like a high speed clicking sound). They can go faulty, commonly it is just dry / broken solder joints on the circuit board inside the housing. It's not too hard a job to remove the stepper motor unit and open up the housing, then you can have a look and see if any of the solder joints are broken,

 

 

i have a auto so i don't see the Idle speed i don't have a rev counter.. im sure my dad took the motor apart and said it don't look to healthy !

[Tommy23]

I haven't read all the comments, but i have just 2 weeks ago fixed my overfueling problem! The tempgauge didn't work so i figured out after long time of thinking, that the cooling system was blocked in the inlet manifold. It causes overfueling because no water could get to the coolant tempsensor, which controls how much fuel it delivers. So check out if the cooling system is fine and not blocked! :) good luck