Colour tune

Colour tune

Author
Discussion

Chadders75

Original Poster:

49 posts

95 months

Monday 16th May 2016
quotequote all
Hi, Has anyone used a gunson colour tune to check that the fuel mixture is ok

Chadders

AdamIndy

1,661 posts

103 months

Monday 16th May 2016
quotequote all
Not on a TVR but yes on other carbed cars. Easy to use and seemingly accurate as the rolling road operator couldn't better it. This was on a tuned Xflow on twin 40 webers. Doing 8 cylinders may be a pain though!

Actually quite cool seeing inside a running engine too.

Chadders75

Original Poster:

49 posts

95 months

Monday 16th May 2016
quotequote all
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 !

Englishman

2,215 posts

209 months

Monday 16th May 2016
quotequote all
Yes, I've still got one in my toolbox, but not used it for 20+ years. IIRC the last time was on an Elan I owned in the late '70's. Wow, that is 35+ years ago, where does the time go!

Chadders75

Original Poster:

49 posts

95 months

Monday 16th May 2016
quotequote all
Got a little video, but don't know if I can put them on this site

rev-erend

21,404 posts

283 months

Monday 16th May 2016
quotequote all
Put the vidoe on youtube and put a link on here.

Chadders75

Original Poster:

49 posts

95 months

Monday 16th May 2016
quotequote all
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.

rev-erend

21,404 posts

283 months

Monday 16th May 2016
quotequote all
Perhaps you have another issue to cause the misfire.

I can see copper on the connector of the coil low tension .. there could be other issues.

adam quantrill

11,535 posts

241 months

Monday 16th May 2016
quotequote all
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.

Chadders75

Original Poster:

49 posts

95 months

Monday 16th May 2016
quotequote all
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

Original Poster:

49 posts

95 months

Monday 16th May 2016
quotequote all
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.

perksy

32 posts

283 months

Monday 16th May 2016
quotequote all
When you say you have tested the injectors have you just checked their resistance or have you checked their flow aswell ?

I'd echo the comment above on checking the coolant temp sensor first though

Have seen a TPS on the way out also cause serious overfuelling

ElvisWedgely

2,714 posts

164 months

Monday 16th May 2016
quotequote all
Also check for air leaks. It's a closed circuit system so any air leak will upset the running especially at idle.

Tony. TCB.

mrzigazaga

18,534 posts

164 months

Monday 16th May 2016
quotequote all
Hi...If it was over-fuelling that bad it would not run at high speed...It would want to die...What is the fuel pressure?...What rating and condition are the plugs in?...Have you got a good fat spark being generated?...If everything else is okay then it could be an ECU problem...The injectors are timed pulses....Wedges are a tad rich on start up and idle but should filter out a bit...Does the smoke smell like raw fuel?..Has the AFM been messed about with?

Chadders75

Original Poster:

49 posts

95 months

Monday 16th May 2016
quotequote all
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. smile


mrzigazaga

18,534 posts

164 months

Monday 16th May 2016
quotequote all
Chadders75 said:
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
Thats about right.....

Chadders75 said:
Air leaks, yes.There are about 4, 3mm holes in the rocker covers. Need to plug them :/
They are probably just the holes for the plug lead clips...They do not go right through...
Chadders75 said:
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. smile
That could be an issue...Although i have just seen the bit about the mis-fire at 2-3000rpm...As Adam said it could be the CTS...Mine was playing up and it was dumping fuel in....Have you tried it with the cold start...9th injector plug removed...This should stop some of the excess fuel...You said a "Blue flame" on tick over...?...Back-fire?....Where this video...Cheers...Ziga

Edited by mrzigazaga on Monday 16th May 23:05

Chadders75

Original Poster:

49 posts

95 months

Monday 16th May 2016
quotequote all
Raw fuel, missed that one. I will say no, but not fully convinced of my answer. Lack of experience, and sense of smell. :/

Chadders75

Original Poster:

49 posts

95 months

Monday 16th May 2016
quotequote all
" 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.

adam quantrill

11,535 posts

241 months

Tuesday 17th May 2016
quotequote all
Air leaks will tend to make it run lean, but still worthwhile sorting out.

Yes the TPS should be checked after the coolant sensor - a "noisy" TPS can cause extra pulses of fuel.

The flow rate is probably good as you are running rich - you have flow! ;^)

If you can reproduce the sooty exhaust problem with the car sat still and tweaking the throttle open to about 3000 rpm, it will be much easier to diagnose.

Chadders75

Original Poster:

49 posts

95 months

Tuesday 17th May 2016
quotequote all
YouTube video - 400se colortune at 800rpm

Now that's a first :/