dellorto problems

[Neil]

Hi,

I am just trying to get my 260z running smoothly. The car has triple dellorto 45s on a standard engine (as far as I have worked out). This seams to be overkill for a standard lump, the dellorto chokes are also 36mm, so I can only assume its jetted wrong etc.

Do you think it will be best to re-jet and getting smaller chokes for the 45s or would you start again, if so what are my options, I have even thought of going back to twin SUs but cant find RHD linkages etc.

The car is running and driving but does not pickup well, pulling away. I keep chucking money at the 45s but now wondering if its worth it at all, any suggestion would be greatly appreciated

Cheers,
Neil.

 

[atomman]

For a standard L24 it was recommended to use Weber 40 DCOE's with 28mm chokes , so think the 45 dellorto's with 36mm chokes would be a bit over the top I rekon ,

Just had a quick read you can use 28mm - 40mm chokes on the 45 dell's . may be worth getting some smaller chokes and a visit to the dyno to get it jetted properly or seeing if you can swop them for some 40's ?

 

[Neil]

For a standard L24 it was recommended to use Weber 40 DCOE's with 28mm chokes , so think the 45 dellorto's with 36mm chokes would be a bit over the top I rekonView attachment 34444 ,

Just had a quick read you can use 28mm - 40mm chokes on the 45 dell's . may be worth getting some smaller chokes and a visit to the dyno to get it jetted properly or seeing if you can swop them for some 40's ?

Cool thank you, im planning to get it back on a rolling road asap. I would swap the 45s for 40s but cant find anyone willing.

 

[jonbills]

I have Dellorto 45's and ran 36mm chokes on my L24, I have 39mm chokes with a 2.9 now and it works great. It will be easier to get it running well with smaller chokes (maybe a 32) but you can get it working with 36s if you want. unless its a modified engine and you're revving it pretty high there's probably not much to be gained from keeping 36s.
first things first though - if you're having problems pulling away then that sounds more like basic balance and idle / progression jet setup rather than chokes and idle to main jet transition. is it really pulling away, or is it in the transition between a slow cruise and acceleration?

 

[Neil]

I have Dellorto 45's and ran 36mm chokes on my L24, I have 39mm chokes with a 2.9 now and it works great. It will be easier to get it running well with smaller chokes (maybe a 32) but you can get it working with 36s if you want. unless its a modified engine and you're revving it pretty high there's probably not much to be gained from keeping 36s.
first things first though - if you're having problems pulling away then that sounds more like basic balance and idle / progression jet setup rather than chokes and idle to main jet transition. is it really pulling away, or is it in the transition between a slow cruise and acceleration?

It feel like it's going to cut out and the car slows, as soon as its past 20mph ish the car drives with no problem.

 

[atomman]

It feel like it's going to cut out and the car slows, as soon as its past 20mph ish the car drives with no problem.

Maybe the idle jets are just to small then and they need a good balance ?

not sure about dell's but the idle circuit on the DCOE's goes up to about 3000 rpm then the mains take over,

 

[jonbills]

Maybe the idle jets are just to small then and they need a good balance ?

not sure about dell's but the idle circuit on the DCOE's goes up to about 3000 rpm then the mains take over,

yeah I agree - something isn't right in the idle circuit or its unbalanced.
what idle jets are you using? I'd think you should be somewhere around 50.
do you have a flow meter? are all the cylinders flowing the same at idle?

 

[Neil]

yeah I agree - something isn't right in the idle circuit or its unbalanced.
what idle jets are you using? I'd think you should be somewhere around 50.
do you have a flow meter? are all the cylinders flowing the same at idle?

I am not sure on what idle jets that I am using, it has been to a tuning company who regularly deal with these cars and said it needs to be re-jetted etc. They balanced everything as best they could. I think I have just invested in a twin su setup for now. Thank you for all the replies.

 

[jonbills]

Glad you're sorted.

 

[Neil]

Glad you're sorted.

Thank you, just looking forward to driving the car smoothly.