sentra Posted January 28, 2008 Share Posted January 28, 2008 having a play with a pair of hif6's and was wondering something, i realise the needles shape is the 'adjusted' part, but does the 'jet' ever change? i put a kit trough each one (haddnt had it running previosuly), which came with replacement 'jets', (which have a diffirent style of pickup), we started the engine and it runs eyewateringly rich right thoughout the adjustable jet height range. so its 1 of 3 things, - incorrect 'jet' - problem with the cold start enrichment valve - fuel pressure -> currently running 4.5psi (measured) on a facet pump. ill put the old jets back in tomorrow, was just intrested/bouncing ideas really 1 Quote Link to comment Share on other sites More sharing options...
Guest sexychevette Posted January 28, 2008 Share Posted January 28, 2008 i fort ur 7 was injctid brah. gutd as bo. stil go hard aye tho aye chur chur edit: its turbs ay g Quote Link to comment Share on other sites More sharing options...
CaMpylobacter Posted January 28, 2008 Share Posted January 28, 2008 careful with pressures. also dashpot springsetc make a difference. get aout 400bookso n s.us, read them all, then spend like 20years playing withthem, and then you may be able to get a decent base tune. rofl Quote Link to comment Share on other sites More sharing options...
peteretep Posted January 28, 2008 Share Posted January 28, 2008 haha, its for a 3.5 range rover v8 motor Quote Link to comment Share on other sites More sharing options...
sentra Posted January 28, 2008 Author Share Posted January 28, 2008 yeah its a factory setup besides the fuelpump. just a simple question. Quote Link to comment Share on other sites More sharing options...
CaMpylobacter Posted January 28, 2008 Share Posted January 28, 2008 word. also be wary that potentially the pressure (if excessive) may have jammed the float valves open or somehting. weird things, s.us Quote Link to comment Share on other sites More sharing options...
BobbyBreeze Posted January 28, 2008 Share Posted January 28, 2008 ^^ as said, could be needle valve in float bowl not sealing properly, which causes fuel height in the float chamber to be higher than jet and the fuel just pisses in to the carb. Give it a tap / take it out and blow through it while lifting up and down the float to check its doing its job. It was this that stranded me in the fucking wellington motorway tunnel in the mini. OR Yes, there are different sized jets, which sounds to be more likely your problem. HIF38/HS4/HS2's use 0.090" jets, while HIF44/HS6 use 0.100" jets. Su's aren't all that bad, you just need to know what can go wrong. Custom needles are pretty easy to make on the lathe with emery paper too, i did the one in my car. Once tuned right they are great carbs imo Quote Link to comment Share on other sites More sharing options...
sentra Posted January 28, 2008 Author Share Posted January 28, 2008 cheers man, thats exactly what i wanted to know but couldnt find anywhere, i know the needle valves are working as i replaced them and bench tested the unit. you dont happen to know what the 'non adjustable' float height should be set to also? 1 Quote Link to comment Share on other sites More sharing options...
BobbyBreeze Posted January 29, 2008 Share Posted January 29, 2008 Unsure off my head, but i do know it is very important. What is the car? It should be in the relevant manual. If its wrong you'll probably have to pack up the needle valve with a washer or something. Had to do this in my HS4. The early carbs had a brass shim for the arm or the float so you could just bend and adjust it. Quote Link to comment Share on other sites More sharing options...
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