The V8 Owners Forum -

hi guys can anyone give me advice on setting up holley 390 p[lease?
have started engine but seems very rich, wont idle, and needs nearly full choke to run???
also should acc?enrichment fuel jets put in extra fuel as soon as you touch throttle??

regards steven

This has been copied from an old archived post from old forum:

Tunning Rover V8 Engines, by David Hardcastle

Installing the Holley 390 CFM on a road car begins with an adequate fuel supply, which should be via a good filter, and pump, At a pressure of 4.5PSI, High rpm missfiring may be due to fuel pressure dropping off, SO make sure delivery stays at 4psi (NITROUS OXIDE USES 7PSI).
Investment in a proper fuel pressure regulator and even a fuel pressure gauge is worth while.
With the fuel supply sorted the carb itself needs mounting without vacuum leaks,
make sure the fuel level in the carb is just below sight plug hole(clear sight plugs are now available)
tick-over can be set using the external stop, Next the idle mixture needs to be set, using the two screws on the side of the metering block, they need to be adjusted more or less even to obtain the highest idle possible(or manifold vacuum reading), after thisa the tick-over should be again be set back to idle using the idle stop screw(NOT THE MIXTURE SCREWS YOU JUST SET),
If when you turn the mixture screws nothing happens then there is a possible vacuum leak,

Eliminating 'bogs' or hesitation during hard acceleration is the next step, This is caused by a delay in the secondary plates opening, This has to be tunned out by trying progessivly heavier diaphram springs(they are colour coded in the kit), and to increase the accelerator pump squirters, these are numbered according to the size of the nozzles.(e.g No26 is a 0.026 in diameter nozzle), these should be increased one step at a time until hesitation clears up while trying to use the smallest possible,
If the car seems sluggish in response to full throttle, but not bogging then a lighter diaphram spring should be tried,
But if no improvement then the fault lies else where and needs to be investigated .
The other areas of the carb for tuning are the main circuits and the power circuits, BUT these rarely need adjustment,
PLEASE NOTE The main circuits-which on the Holley 4160 390 cfm 4 brl are regulated by a metering plate - AND ARE BEST LEFT ALONE!!!!
When fitting a Holley it is possible to end up with erratic idle. depending on the type of air cleaner fitted. This is caused by insufficient clearance between the bowl vent tube and the air cleaner lid, put your finger over the tube(remove filter cover first to do this) if the symptoms repeated then here's the problem.

Also Vovord gave me this link from his site on how to set up using an O2 sensor,
http://www.telusplanet.net/public/giles ... rb_jet.htm

thanks thats a great help! only problem is s/h carb i bought only has the parts that are already fitted!

what do i do with timing settings?? i no they were fine before changing carb but now holly wants to blow flames up through inlets! am i right in thinking su carb only creates vacunm and advances when under load? i.e is the holley now advancing all the time??
any help gratefully recieved
regards steven

First off, if it needs a lot of choke to run it's lean, not rich.

Second, I think you can get tune up kits for these carbs which contain a selection of springs etc.

Third, as far as I know, all carbs run the same kind of vaccuum advance for the dizzy & it always varies with load. Someone may correct me here...

One thought is intake manifold leaks; these seriously screw up the idle and give you a lean mixture.

If (like me) you don't know what you're doing it may be better to take it to a tuning specialist, preferably with a rolling road. It aint cheap, but you should get the best results.

Hi
I would check for leaks and get it to Idle and make sure you can tune it before you take it to a rolling road, these guys are expensive and don't like being used to fault find an induction problem (just read Dave Walker in PPC each month, and he seems a very tollerent and understanding chap).
All they do when they find a problem is send you away to fix it and charge you for the remainder of the session! you pay for half a day and don't get any further forward. I would also renew all you ignition system the day before you go as well and make sure the engine bay is spotless otherwise again you will be sent away to change it all and still pay for a half day!!!!
Use WD 40 or damp start to find any leaks, use the plugs and tail pipe to decide whether it is rich or lean (plugs will also tell you if a given cylinder is lean. look at the headers, if it is rich on a rover the Mixture may still be burning when it enters the exhaust) sort it first.
Best of luck
Mike
Mike

to get it to idle i have to turn idle screw in so butterflys open alot and if you look in venturi fuel is literaly being pored in! i am a mechanic just never set up v8 or holley before???

on the side of the float bowls is a level plug, a slot headed brass screw
undo this and see if fuel is pouring out, mind for fuel going every where dont want a fire,
if fuel is coming out a lot the float level is wrong, or is stuck.

First make sure float level is right as T says, they're also said to be sensitive to fuel pressure, mine was.

There's a £6 book that's helpful, Real Steel among others have it.
RS do rebuild kits for about £25 if it needs a sort-out

When I had mine I grabbed some stuff off the net and made this Word document (right-click link, choose 'save target as' to download it). Its a Holley rebuild+adjustment manual plus a spot of misc info scooped off the t'internet (so may be b*ll*x lol).

this is all great help thank you!
i am running off std p6 mechanical pump as engine is fitted to rear of my beetle! )there is no fuel return to tank)
i have another holly 390 which i think ill bolt on and see if that is a better starting point??
i went for holly as i though it was easier to set up! obviously i was wrong there!!!!!!

Hi speedy, I'm about to do the same conversion to my bug, putting a s'charged v8 in the back of there. I'm getting my adaptor plate from DS tuning over in germany, and will fab up the mounts when it's on. Have you got any advice on the conversion? Where did you get your adaptor from? It'd be great to bounce some ideas off of someone who's done this already.

i bought bug with conversion already done (about 10 years ago)
i have std 1500 gearbox and it seems to be holding up fine, std beetle clutch realy isnt up for the job so looking to upgrade to 2400llb plate at some point!
im happy to give any advise i can just pm me, will try to post a few pics too!
any one give any advise on fuel pump etc???