Board logo

Gunson Gastester?
David Jenkins - 17/2/07 at 04:15 PM

I've been trying to get my x-flow to tickover nicely. Started with a colortune, but as usual I didn't manage to get a satisfactory outcome ("Is that flame blue, bluish-white or bluish-yellow?".

What I really need is a proper exhaust tester - are those Gunson Gastesters any good? Are they easy to use?

I had a look at the web pages for the tool hire shops - no-one seems to have any for hiring out.

David


fatfranky - 17/2/07 at 04:36 PM

David

I have one of these in my garage although i must admit it's ages since i used it, but i seem to recall that it worked well.

If i remember right they also do (did?) a professional version that was digital.

If you were a bit closer you could have borrowed mine to try it.


britishtrident - 17/2/07 at 05:21 PM

Colourtune should be fine, what carb are you running ? You wil find using a Colourtune it needs to be slightly at the rich (yellow) end.

Most times when the idle mixture is difficult to set something else is wrong, worn carb spindle, rocker clearance too tight, burn't exhast valve, duff plug or lead, ignition timing or points gap.

The car is on points ignition the xflow is particularly sensitive to points gap and the different makes of distributer Ford fitted use different contact braker points gaps. The Ford/Fomoco/Autolite distributer is very prone to the points gap (0.025" closing up.


Gunson Gastesters are pretty useless, they last about 5 minutes.

[Edited on 17/2/07 by britishtrident]


David Jenkins - 17/2/07 at 05:28 PM

The carb is a Weber 32/36 DGV - it sort-of ticks over, but it's a bit erratic and sometimes stops.

The ignition system is megajolt, but the behaviour was the same with the previous Bosch Valencia dizzy.

Rocker clearences recently checked & OK, newish plugs and brand-new leads, compressions good.

The engine runs well in every other respect - just that I have to set tick-over speed to around 1100 rpm to be reliable - this may be normal with a BCF2 cam!


rusty nuts - 17/2/07 at 06:38 PM

You should be able to adjust the idle timing to give more advance which will help with the idle.


Danozeman - 17/2/07 at 08:53 PM

I had to set the idle advance a little more with my zetec and megajolt to get it to idle ok.

May be worth a try.


paulf - 17/2/07 at 09:30 PM

It is possible to set the lowest advance bins higher than the advance at the normal idle revs to give the engine an increase if dropping off idle.
For example if idling at 15deg at 800 revs set a lower advance bin for 25 degrees at 500revs then if the idle revs drop it will compensate and stabilise the idle.
Paul.


timf - 18/2/07 at 06:29 PM

David
I have one you can borrow if you wish
its the digital one
tim


jolson - 18/2/07 at 08:27 PM

I've had an older, analog model for several years, and it's surprisingly accurate. I do a tune-up just before MOT time and it agrees with MOT centre's tester within a few tenths of a percent.