Colour tune

[Chadders75]

Hi, Has anyone used a gunson colour tune to check that the fuel mixture is ok

Chadders

[Chadders75]

Ok, so just went for a little spin, then put the colortune in and well, yes, nice blue flame at tick over.

Not quite what I had expected, as spitting black smoke out under acceleration !

[Chadders75]

Got a little video, but don't know if I can put them on this site

[Chadders75]

Extracted a picture

Hopefully!



Now to my understanding, with the flapper AFM if the fuel mixture is correct at tick over it should be OK through the range?. So why the black smoke. Doesn't smell or look like oil smoke. Plus it's running lumpy at around 2 - 3000 rpm. As if misfiring.

[Chadders75]

Yes it has a lot of issues, but slowly chipping at them.
Tested all the injectors all ok, fuel pressure ok.
Need to test cylinder pressure, ignition and all the sensors, I will then feel happy to take it on longer trips

[Chadders75]

adam quantrill said:

Black smoke under acceleration is a sign of overfuelling.

First thing to check is that the coolant temp sensor is OK when hot - should be around 300 ohms, measure it again at the ECU multiplug to make sure the loom isn't the culprit.

Good call, I will test that tomorrow. There is a temperature sensor in the AFM as well, which needs checking.

[Chadders75]

Eeek lots of question, memory test 101.

Injectors removed and tested independently, all consistent jets but didn't measure flow rate. (Next time).

Fuel pressure 2.5 ish

Air leaks, yes. There are about 4, 3mm holes in the rocker covers. Need to plug them :/

The AFM has been fiddled with, looks like external fuel pump switch. And the lid has been off.

Haven't looked at the ignition much yet, just used the colortune, might go round all eight and check them in the same way.

Have I missed any, probably. New test session tomorrow.

[Chadders75]

Raw fuel, missed that one. I will say no, but not fully convinced of my answer. Lack of experience, and sense of smell. :/

[Chadders75]

" just the holes for the plug lead clips."

That's good, I will check them out as well tomorrow

Thanks for all the help, I will let you know how I get on.

[Chadders75]

YouTube video - 400se colortune at 800rpm

Now that's a first :/

[Chadders75]

:/ huff. Me to, it's in my videos ! But don't know how to share it.

As for the coolant temperature sensor and the throttle sensor, both check out ok which is a good thing.

[Chadders75]

Got it https://youtu.be/WSaVVe3JH9s

Don't think it was worth all the trouble

[Chadders75]

That's the colortune plug terminal (repaired) at the plug. it's very old, almost as old as me but it works quite well.

I will keep looking, I have got to find the problem eventually.

[Chadders75]

New video. https://youtu.be/I7cjOsx5D7s

Missed the hunting after starting, but just wanted to show how thick the soot is in the exhaust.

Do they all sound like this?

[Chadders75]

Sounds like I still need to get a CO reading, does anyone use the Gunson gas tester.

[Chadders75]

Oooo, that would be an interesting test. CO meter V colortune.

[Chadders75]

Well, now starting to run out of things to test.

Compression good
New spark plugs
New air filter
Coolant temp. Sensor good
Accelerate pot sensor good
Fuel pressure good
Injectors good

Things still to test

Timing
CO
+ everything else

Did see another post that mentioned dry solder joint in the ECU, might keep that one till last.

[Chadders75]

The gastesters sound to be a bit like Marmite, but apart from taking my car to the local garage, which would be the equivalent of taking it to the petting zoo. I don't think I have much option when it comes to checking to fuel mixture.

Did take it for a run last night, sound a little better, but still hesitant when the revs pick up.

Will take a hamer to the ECU today, thanks for the tip

[Chadders75]

Well still chipping away, just checked the timing to make sure that it is ok, and it is sitting at 4 deg. BTDC on premium unleaded. But then as the engine started to warm up fully I noticed steam coming from the radiator.

So more questions. Radiator replace or new and price. And do all the wedges have the pipes go over the cross bar like in my photo.

[Chadders75]

Hi, thanks for the info, once again it's much appreciated.
Will have a look round for a local repair service, but living in north Norfolk, me thinks they might be in short supply, but you never know.