jonbill

A couple of things that might help: When a cylinder doesn't fire, then the wbo2 reads full lean because the gas passing over it is atmospheric air. None of the oxygen has been used to burn fuel. This happens whether the misfire was because the mixture was too lean or because it was too rich. So when you're at 11 afr and go richer, it wont burn and so it shows lean. Telling TS that you have bigger injectors when you haven't changed them will make it leaner, because the calculation assumes that it can deliver the required fuel in a shorter time. Assuming your injectors are big enough for your power level, when you're maxed out on the VE table values (as your are) a larger required fuel value will give you more head room.

Pull the cam out and get it reground to a more aggressive profile. You'll get more power (maybe) and more lash clearance. Win win.

50s ftw.

Just to be a bit contrary: IF you can find someone competent with dual sidedraughts, I guarantee it will be a lot cheaper to get the webers spot on than to supply, fit, tune ITBs and EFI

I'd look at where the throttle plate is, in relation to the progression holes. You want it to start uncovering a progression hole at the first movement of the throttle. I think it is possible to setup idle by keeping the idle bypass screws shut and opening the throttle to the first progression hole, but you've then got a fair way to go to the next progression hole. Correct way is to have idle on completely closed throttle and idle air supplied by the bypass screws.

I expect the missing bit is in the sump. I'm sure you'll be able to epoxy it all back together. The cam lobes look ok, thats the main thing to check out with the spray bar broken. I've never seen those bits made of cast ally, mine have all been pressed steel.

Maybe try the next size up idle jet, that might cover the transition hole, might richen it a little at wot too. Also check the float levels if you haven't already.

I'd check that the accelerator pump is working correctly first. Take the carbs off and see if they squirt fuel out the back.

Will it get up to the higher revs ok if you don't give it so much throttle? If it can accelerate up at part throttle without any hiccups, then its probably the accelerator pump circuit.

To ensure enough pressure and flow to the bottom end.

Mine is r200 with r200 moustache bar. is yours an r200 moustache bar? i believe they are different. Maybe not the wrong way round, maybe just the wrong bar....

Not sure what thats in reference to, so I may have the wrong end of the stick, but ignition timing jitter has been well measured in Speeduino and there's no problem (would be my conclusion). https://speeduino.com/forum/viewtopic.php?p=63829#p63829

Surely your moustache bar is back to front?

I'm very happy with my Speeduino. Hard to beat the price and it has all the features I need (and more).

Fair enough. Did the conversion kit add a spacer or any other material to the clutch mc bulkhead mount point?

I don't believe changing the cam will make any difference. Problem is elsewhere. Something in the intake path perhaps.

How much rod is visible at the slave cylinder? Have you changed the clutch?

https://www.comp.co.uk/products/product.asp?item=ml1582-302-129

Looks like there are 3 z31 manual gearboxes. https://www.z31.com/transmission.shtml I'm sure they have all gone into an s30 in the past.

Fwiw, the front jet in the head actually supplies oil from the head to the timing chain tensioner gear.

Didn't you say you'd tried a new high volume pump too? So can't be that - pressure is being lost somewhere in the system. I'm really not sure whether the effect of excessive clearances or unplugged galleries will be seen from low rpm or not. I could be persuaded either way 🤔 Another possibility might be a partially blocked gallery - flows enough to get 40psi at your measuring point, but no more. I suspect the true diagnosis can only come with stripping the engine down and checking everything.

What modifications does the engine have? Maybe there's a missing plug in the crank or the front of the oil gallery, or the oil jet to the head is too big or the bearing clearances are much too big.

My experience is the same as @madkaw. On my 2.9, it looked like that at 200 miles and 10,000 miles. Edit: I haven't had the 3.2 open again yet, but I expect less of it there. Longer rods and all that.

Pick a car from 1980 with L16 and I expect it's alternator will fit.

For instance: