Outer Limits 4x4 Board

I have an impco 200 on my Tb42E gq.

I normally get around 23l/100km around town and 20l/100km on freeway.

Anyway recently my economy has shot up closer to 30l/100km with no change in my driving.

I did notice a vacuum leak the other day that may have been there for a long time. The installer has used a wetsuit material sock over a steel pipe that has 2 big holes in it. I'm guesing it was used to stop the air box blowing up if it backfires.

It smells rich at idle and the idle mixture adjustment seems to do nothing

What can i do?????



Cheers

James



PS: Should i save up and get a 225 mixer or is the 200 enough?

Change your air filter! if its old put a new one in it. you need to make sure you have no vacuum leaks and also you need to change that backfire sock over. If no better get it tuned by a gas shop!

Air filter is brand new, all vacuum leaks fixed and have got rid of the sock all together (closed up holes)

You could have either a shagged mixer or convertor you should probably take it to a gas shop so they can check it out for you thats if your mixer adjustment is not working

Take the converter out, strip it and clean it. Also, run the face of the needle seat sealing surface over a sharpening stone to square it and remove any ridges.

I just did mine the other week and it wasn't too bad. The mixer on the other hand was bloody filthy. Saying that, my economy is no better after the gas parts servicing (because i have a 225 on a Ford 302W).

225's are cheap as chips ($50-$100).

jimbo get it on a dyno, that will fix it properly. If ur in se. Vic, take it 2 lpgas1 in lilydale, the boys there are awsome.

Jimbo wrote:I have an impco 200 on my Tb42E gq.

I normally get around 23l/100km around town and 20l/100km on freeway.

Anyway recently my economy has shot up closer to 30l/100km with no change in my driving.

I did notice a vacuum leak the other day that may have been there for a long time. The installer has used a wetsuit material sock over a steel pipe that has 2 big holes in it. I'm guesing it was used to stop the air box blowing up if it backfires.

It smells rich at idle and the idle mixture adjustment seems to do nothing

What can i do?????



Cheers

James



PS: Should i save up and get a 225 mixer or is the 200 enough?

'

if the idle mixture does nothying than your mixer needs attention.
just get a rebuild kit for it.

Jes

I would also suggest pulling the mixer off and having a look inside it as the impco mixers with age wear inside and the valve can rooster inside giving unstable mixture as i said if you dont know how to pull it all down i would take it to a gas shop kitting these mixers might not be the way to go as the wear in metal components will not be reapairable i aint a fan of kitting converotrs / mixers due to the corrosion factor and also wear in metal components!

I suggest you remove your mixer, inspect it for wear & give it a good clean, you will find it is full of that oily residue found in the LPG we use. Be careful not to damage the diaphragms inside & give them a going over with some silicon lube to keep them soft before re-installation. If the converter hasn’t been off in a while do the same. If you are not super confident, don’t play with mixture settings yourself. Set it too lean & you could do some damage over time, too rich & you are blowing cash. What might seem perfect at idle or low revs could be a lot different at 3000rpm. A gas dyno tune will make sure it’s running sweet over all rev ranges for the cost of about $130. Good luck.

Thanks for all the replies.

I have taken the mixer apart and it was very clean (taken it apart and cleaned it b4) although i havent played with the converter yet.

I took it to lpg1 when i first bought the car and they did do a good job....lilydale is just so far away.....i'm out near point cook.

One more point, i did replace the air filter recently from a genuine nissan to a cheaper aftermarket one (I run a zd30 airbox) however the genuine nissan filter was over 3 years old and covered in crap!!

nah shouldnt matter the other thing to check is where abouts the main mixture valve is sitting on the mixer where it reads L and R its like a 15mm spanner sized valve make sure its around halfway roughly maybe a tabe more towards the r side then try it but i would really take it to dyno shop for tune

Try Sass Automotive out Werribee way.