32 replies to this topic

[danie garry]

well lads, iv just fitted a stage 1 kit i got from minispares to the 998, freeflow manifold, RC40, alloy inlet and AAU needle. couldnt get the car started so started playing with the mixture a bit and got a little splutter and now i'v finally got it running, with the mixture nut down 9 full turns from the top! from all the info iv found on here, that seems like an awful way down!
surely this is way off??
the car was running well before i fitted the kit so i havnt fiddled with the choke or idle, should i have to?
the car has a powerspark dizzy fitted which is giving good spark to new plugs and leads, i havnt altered the timing as it was running fine before.
tappets done, no air leaks, all hoses and breathers are good, spark and fuel! but the fuel just seems very rich, i'v managed to lean it off by 2 turns but thats still fairly rich?
any ideas lads??
going to give it a quick drive now and see how well it drives

[KernowCooper]

Once you have it idling if your SU has a lifting pin, lifting it if the engine revs up and stays there its to rich, if it faulters and dies away/stalls its weak, should rev up slightly and settle which is right. You may have to adjust the engine idle after making changes to the mixture. Thats the trouble with stg 1 kits a there are people who spend time and develop the kit, other companies copy the needle supplied but some components are different. What ever you should be able to get the mixture correct at idle, its after that on test where the stages on the needle may not suit the state of tune on the engine, with flat spots or poor performance.

 

The replacement needle is fitted flush with the bottom of the slide I assume?

Edited by KernowCooper, 06 May 2014 - 03:22 PM.

[Vipernoir]

9-flats down is believable, 9-turns down there is something very wrong.

 

I would suspect there is a massive air leak somewhere.

[danie garry]

Once you have it idling if your SU has a lifting pin, lifting it if the engine revs up and stays there its to rich, if it faulters and dies away/stalls its weak, should rev up slightly and settle which is right. You may have to adjust the engine idle after making changes to the mixture. Thats the trouble with stg 1 kits a there are people who spend time and develop the kit, other companies copy the needle supplied but some components are different. What ever you should be able to get the mixture correct at idle, its after that on test where the stages on the needle may not suit the state of tune on the engine, with flat spots or poor performance.

 

The replacement needle is fitted flush with the bottom of the slide I assume?

 

no lift pin, its a '90 so and im pretty sure its the original carb. the needle is fitted on the collar and is flush to the bottom of the slide

 

9-flats down is believable, 9-turns down there is something very wrong.

 

I would suspect there is a massive air leak somewhere.

 

started at 12 flats as thats what i had seen on here and then moved it to 18 and just kept going 2 flats at a time and it ended up at 54 flats!

iv been over and over it and all the gaskets are new and everything is tight, 99% sure there isnt an air leak!

cheers for the input lads

[KernowCooper]

With it running spray wd40 around the manifold gasket and carb gaskets to check for leaks

[daenesh]

whats a lifting pin?

[danie garry]

With it running spray wd40 around the manifold gasket and carb gaskets to check for leaks

 

done, no leaks! brought the nt the whole way back up again, the jet supposed to be level with the bridge, is that level with the brass bush or level with the cast bridge in the carb??

[Outofthegame]

Is the float chamber sitting vertical? 

 

It's possible the new inlet manifold has affected the angle the carburettor sits at

Edited by Outofthegame, 07 May 2014 - 03:08 PM.

[danie garry]

started from scratch again, took the needle out and put it in again, its definitely flush with the slide! brought the nut up so the jet was level with the bridge and took it down 15 flats, tightened all the manifold and carb-manifold nuts and she fired up, sounds fairly ok!

now there was another problem, i was getting fuel out the overflow from the float bowl so i swapped the needle valve with another valve from another carb i had and it seems to have solved that 1!

the engine will now start and run on choke or throttle but with the choke being pushed in it dies, guessing its just the choke that now needs altering? 

i only need the car starting and running reasonably ok as i have it booked in for a rr session on friday

videos to follow

*edit for videos

choke and throttle

revs with no choke

 

just choke

 

@outofthegame, id say its ok, dont think minispares would sell it if it altered the angle that much...would they?!

Edited by danie garry, 07 May 2014 - 04:08 PM.

[KernowCooper]

Lifting pin is in the Carb body on most SU's, this lifts the slide externally for checking the mixure.

 

Choke wont need adjusting, if its not correct and wont run correctly then its a needle change required.

[danie garry]

so the only thing that needs work after a stage 1 is the mixture setting? 

cheers for the help

[KernowCooper]

And re adjust the idle

[danie garry]

And re adjust the idle

 

just had a play around with the car and i think i have it sorted! its idling well and pulling well in first and second but under load in third and fourth its giving some nice pops and bangs! put the colourtune on it and its a bit rich, leaned off the mixture and it even idled better, cant take it for a spin til morning though, the back lights dont want to play ball!

[KernowCooper]

If you have set the idle mixture correctly and then you have flat spots further up the range on the road, then it points towards points on the needle are not matched to the engines requirements and thats where your custom needle comes in on the rolling road session

[danie garry]

If you have set the idle mixture correctly and then you have flat spots further up the range on the road, then it points towards points on the needle are not matched to the engines requirements and thats where your custom needle comes in on the rolling road session

 

i was a bit rich on my last run so il see how it goes in the morning and hopefully it'l make it to the tuners friday!

cheers for the help, appreciate it