37 replies to this topic

[terry tibbs]

Just to check, when using the silicone vacuum tubing, do you still use elbows or just connect the tubing directly to the fuel trap, etc?

 

[RooBoonix]

Just to check, when using the silicone vacuum tubing, do you still use elbows or just connect the tubing directly to the fuel trap, etc?

 

 

The pipe is normally flexible enough to not require the use of elbows. Providing the internal diameter of the pipe is around 3mm you should be fine with just the silicone tubing.

[terry tibbs]

 

Just to check, when using the silicone vacuum tubing, do you still use elbows or just connect the tubing directly to the fuel trap, etc?

 

 

The pipe is normally flexible enough to not require the use of elbows. Providing the internal diameter of the pipe is around 3mm you should be fine with just the silicone tubing.

 

That's brilliant, thanks. I've found some on eBay with 3.2mm (must be the one you have mentioned previously so i'll order that up.

Thank you.

[peter-b]

Its easy enough to check the fuel trap, you can just put it in some water and, using a piece of hose, blow some air intro it and look for bubbles.

[pothole]

As the silicon vacuum pipes seems to be popular I have also ordered some off EBay I don't think these are my problem, as the car has always run well, it is just running too rich, going to pick up the fuel trap today and if that does not improve it, I think someone mentioned the next step is the lambda sensor. I have ordered the special socket off EBay, I have had a look at the location of the sensor it looks a right bu***r to remove

[humph]

Have you checked the power is getting to the lambda sensor before you change it? It'll get expensive buying new bits to replace items that are working perfectly well.

[spiguy]

If you suspect the lambda is causing a problem, then to test your theory just disconnect it. The car will run perfectly well with it disconnected, using an assumed reading. No point going to all the expense and hassle of replacing it to potentially find it wasn't the cause of the problem.

[pothole]

Vacuum pipes replaced, fuel trap replaced but still running rich but one thing I did notice that starting from cold the revs are low then after 30 secs the revs increase, I would have thought it to be the other way around. How do I check the voltage to the lambda sensor, and I am unsure as to what disconnection of the lamba will achieve.

But on the plus side always being a carb man and a little apprehensive of the mini injection system it is not so daunting anymore as I learn a little more each day.

[humph]

Have a read of these

 

http://www.theminifo...e-from-exhaust/

 

http://www.minifinit...hp?f=22&t=86339

 

This thread here talks about general injection problems and is very helpful.

 

http://www.theminifo...oint-injection/

[spiguy]

As far as what disconnecting the lambda would achieve, if it is faulty and giving the ECU wrong information about the fuel mixture, then the car will fuel incorrectly. If you disconnect it, the ECU will assume a typical value in the absence of the signal from the lambda, and will fuel accordingly. If everything is working correctly, disconnecting the lambda will make very little - barely noticeable -  difference to the running of the car. If however the lambda is faulty, the symptoms will dissappear if you disconnect it, it is a very quick and easy way to tell if there is a major fault with the lambda sensors operation.

 

I advised this to another SPi owner on here with an apparently rich running car, and as soon as he disconnected it the car ran fine, proving that the lambda was faulty. In his case it was reporting a false lean condition, resulting in the ECU increasing fuelling (wrongly in real terms) which caused the car to run rich.

Edited by spiguy, 16 August 2015 - 10:42 PM.

[FlyingScot]

Spiguys advice will give you a quick yes/ no as to whether the issue lies with the lambda sensor.

You can also measure its response (in the absence of a code reader) using a multimeter as described in this thread http://www.theminifo...-oxygen-sensor/

FS

[spiguy]

Incidentally, you can't just leave it disconnected if indeed it turns out to be the culprit, whilst the car will apparently run fine without it, it would be very unlikely to pass an emissions test. Also, it may over time affect the CAT since the assumed value the ECU uses in the absence of a good lambda signal errs on the rich side.

 

Cheers

Craig

[pothole]

Thanks for all the great info, but I am not sure if I have sorted it.

I left the battery disconnected all night, reconnected it this morning and started it up left it running for 15mins and the temp gauge was sitting between red and middle. I then removed the spark plugs and cleaned all the black soot off each one and put them back.

Started it up again left it running for 20 mins checked the gauge again and sitting in the same position between red and halfway revs read 1000 on counter so not racing anymore, took number 1 and 4 plug out and no soot at all revved it and no black smoke, so does it seem that it has sorted itself with changing the vacuums and fuel trap, is it ready for a MOT now.

[pothole]

Decided I'm an idiot, I have been doing a little research on the Gunson Gas Tester and I forgot in my garage somewhere is a Gunson Colortune all I need to do is find it and check if I am getting a nice blue burn.

[FlyingScot]

Thanks for all the great info, but I am not sure if I have sorted it.
I left the battery disconnected all night, reconnected it this morning and started it up left it running for 15mins and the temp gauge was sitting between red and middle. I then removed the spark plugs and cleaned all the black soot off each one and put them back.
Started it up again left it running for 20 mins checked the gauge again and sitting in the same position between red and halfway revs read 1000 on counter so not racing anymore, took number 1 and 4 plug out and no soot at all revved it and no black smoke, so does it seem that it has sorted itself with changing the vacuums and fuel trap, is it ready for a MOT now.

If it's sitting between red and middle on temp its reading high; either she's running hot or you temp sensor is u/s.
When warmed up it should sit one click below the middle as I noted in post #5.

FS