I may just order them just in case, cause as you know international shipping is currently horrible with Covid; especially since these little parts all seem to come from the UK.

if you were in the UK I could lend you my box of spares. :)

2 hours ago, jonbill said:

4 hours ago, spoolin4life said:

I may just order them just in case, cause as you know international shipping is currently horrible with Covid; especially since these little parts all seem to come from the UK.

if you were in the UK I could lend you my box of spares. ?

That would be amazing haha. I'm in Canada unfortunately! I have a few assorted sizes already.

Would you go one size down with the jet holder or two if the 45 idle jet isn't lean enough? .4 is a level below and .9 is two lower I believe 

I only have two idle holders, .2 and .1, so I work with them.

 

 

On 5/24/2020 at 7:14 PM, jonbill said:

I only have two idle holders, .2 and .1, so I work with them.

 

 

I'll see if the 45 idle jets fix it if not ill make another order and wait lol. Thanks for the help Jon!

I'll keep you posted. 

On 5/24/2020 at 7:14 PM, jonbill said:

I only have two idle holders, .2 and .1, so I work with them.

 

 

So it helped a little bit I found it still went rich when I tap the gas but super lean when idling. My larger issue is now that I have a multiple misfire on 3 cylinders (2, 3 and 4) ? I did 4 full throttle pulls and afrs were 11ish which was way better but as soon as i went to park it i noticed the misfiring. I feel I have done engine damage somehow. I replaced the plugs and didn't make a difference. So compression testing later. Hoping its something basic and not internals.

Edited June 18, 20204 yr by spoolin4life

did you adjust the idle screws? I would expect you'd need to open them a bit to keep the mixture right.

the "idle" jets supply both the progression holes and the idle screw. the idle jets alone determine mixture during progression, the idle jet and idle screws together set the fuelling at idle.

whe you go full throttle, the fuelling is determined by main jets and emulsion tubes so isnt a good test of your new idles!

7 hours ago, jonbill said:

did you adjust the idle screws? I would expect you'd need to open them a bit to keep the mixture right.

the "idle" jets supply both the progression holes and the idle screw. the idle jets alone determine mixture during progression, the idle jet and idle screws together set the fuelling at idle.

whe you go full throttle, the fuelling is determined by main jets and emulsion tubes so isnt a good test of your new idles!

I did open them just a bit. I opened them up roughly half a turn but when I tapped the throttle it would still go to 9ish. Although the holding throttle was much better around 13-16. So I left it there. The driving was quite good also.

The reason I did the pulls was because my engine builder asked me to do a few full throttle pulls to see how the engine was as i had just finished breaking it in and afrs seemed safe. Sadly I don't feel so great now. ?

12 hours ago, jonbill said:

did you adjust the idle screws? I would expect you'd need to open them a bit to keep the mixture right.

the "idle" jets supply both the progression holes and the idle screw. the idle jets alone determine mixture during progression, the idle jet and idle screws together set the fuelling at idle.

whe you go full throttle, the fuelling is determined by main jets and emulsion tubes so isnt a good test of your new idles!

Engine is toast. Compression was 110, 90, 110 120, 120, 130

Bigger problems now 

Engine is toast. Compression was 110, 90, 110 120, 120, 130
Bigger problems now 

that doesn't sound good. engine out then.

"Toast" doesn't sound right.  If it's freshly built it seems like the rings just didn't get seated correctly or are wrong for the cylinders.  Might just need new rings.

Just being positive.  

2 minutes ago, Zed Head said:

"Toast" doesn't sound right.  If it's freshly built it seems like the rings just didn't get seated correctly or are wrong for the cylinders.  Might just need new rings.

Just being positive.  

Ya I'm not sure. The cars compression was good prior to doing the few full throttle pulls. The car still runs but I'm obviously not driving it now. I'm hoping it's just head issues. 

More datsun problems 

You might check other things before you take it apart.  If you didn't hear detonation or rev to 8 grand there's no reason for something to break.  Could be something simple like valves getting loose.  Rings on one side, valves opening and closing correctly on the other.  That's all there is to creating pressure.  I'd give it a good inspection and "re-tune" before taking it out.