Few AAZ questions

Post by **Iceworx** » 22 Apr 2012, 21:57

Evening chaps,

Finally got the AAZ in the bus and running, but I have a few slight issues to sort out.

1st one is smoke. On a cold start up is chuffs it out, grey thick stuff. but once the engine is up to temp it's fine. There are two wires coming out of the pump from the middle of the four fuel outlets, any idea what they are for, as I cannot find anything relating to them?

I always thought grey smoke was too much fuel going in? I've not got the cold start connected yet, as as far as I know, that will increase the fueling when cold...

Secondly I have a slight misfire when cold at idle. i suspect this may be down to a sticky injector as the engine has been stood for several years. Can standard AAZ injectors be ultrasonically cleaned? or am I better off just sourcing some replacements?

any info that can help on any of the points would be spot on!

Post by **ringo** » 23 Apr 2012, 06:00

Try new glow plugs first. Sounds like one or two are knackered.

Got a photo of your pump? I'm not sure what wires you mean.

Ringo

Post by **Iceworx** » 23 Apr 2012, 07:03

Ringo, the plugs are brand new.

I'll upload a pump piccy today

Post by **jtwhitestar** » 23 Apr 2012, 20:00

had this on my aef and found out it had a pump advance solenoid for when it was cold. check cold advance may be worth a shot.
if i wrong sorry in advance.
jt

Post by **fodtommo** » 23 Apr 2012, 21:42

Hi - The smoke you desciribe is not really cuased by overfueling, it is caused by unburnt fuel / inefficient burning.

Definately connect your cold start, if i forget to pull my manual one, it does not fire well and when it catches it is lumpy as anything for about 5 mins.

Remeber it is not a 'choke' as with a petrol engine - it advances the fuel pump timing by about 5 degrees rather than increasing the fuel quantity. This is because as the temperature of combustion increases as the engine warms up, so the compression ratio increases. I could pop in a lovely graph here but it would bore everyone to tears

In a nutshell a lower compression ratio will require an advance state of ignition timing in order to effectively burn all the fuel.

Just pull the cold start on the pump, and hold it on whil starting - I think this is your problem

Hope this helps, tom

Post by **Iceworx** » 29 Apr 2012, 19:16

http://youtu.be/YGaiebGPwpQ" onclick="window.open(this.href);return false;

I've uploaded a vid of the engine running. Hopefully this gives a better idea of what I am trying to explain.

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