1985 rover v8 3.5 EFI tuning

[oflynno]

okay i'm a complete newbie to v8's(bought it friday last)

what is the best way to fine tune this engine to run a bit smoother
it seems to want to cut out on idle

how do i identify which efi system i am running?

thanks

[bodger]

silver ECU = flapper
black ECU= hotwire

could be the breather connection on the side of the inlet plenum blocked
on topp of the rocker cover you wil find a tall tube like thing with a large black pipe off the top , that pipe then goes round to the side of the inlet plenum ,

there is only a very small "dogleg" drilling into the manifold , take the pipe off of the rocker cover end and blow through it that will tell you , if your cheeeks bulge it's blocked then wipe the oily ring off your mouth ...
no really that the best way to tell if it's blocked
it blockes up very easily as it's a very small hole and it can carbon up , it's also the cause of a bulgeing valley gasket too ...easy to fjx just drill straight through the hole
whay happens is as it warms up the extra air valve shuts and not enough air bleeds into the idle control

[oflynno]

cool i will look at that this evening and hope it is just that

thanks for that tip

[ChrisJC]

Also, if it's hotwire, then there is an idle speed control valve on the back of the plenum, and they have a tendency to get a bit sticky. I believe that they can be removed and cleaned up.

Chris.

[rob b]

Also, if it's hotwire, then there is an idle speed control valve on the back of the plenum, and they have a tendency to get a bit sticky. I believe that they can be removed and cleaned up.

Chris.

I think he is running the older flapper system mate.

[oflynno]

yep its a flapper

thanks rob b for putting me in touch with here v8porn

i am going outnow to check things out and will report tonight

[oflynno]

ta very much

the pipe was clear but the metal pipe into the rocker cover was blocked with pure black crud

i pushed out the pot scourer type stuff for now but will pick up some new stuff for it

it is running very well now on the idle

thanks for that

[ramon alban]

what is the best way to fine tune this engine

Hello Bloke,

From the questions and answers so far, it sounds like you are running a bog standard Rover SD1 Flapper, single plenum system.

Mind you - 23 years on - it could be modified in many ways, but assuming that your engine is in good mechanical condition with correct cam/lifter performance and timing, good compression within acceptable limits on all eight cylinders, good exhaust system with no leaks and fresh engine lubrication plus new filter if required, then:

There are 15 things that you can do with your Rover SD1 Efi Flapper System that can change or improve performance from its current condition.

1 Clean all ignition components externally and internally (where possible), spray with moisture inhibitor such as WD40 and wipe dry.

2 Check security and eliminate any corrosion on all ignition LT connections right back to the ignition switch, including local earths.

3 Clean and re-gap the spark plugs - replace if necessary.

4 Check for damaged or out of spec (suppression resistance) HT leads, Clean and replace if necsssary.

5 Set up ignition timing to just eliminate pinking with your chosen fuel.

6 Ensure that the plenum idle air gallery is clear and not contaminated with goo.

7 Likewise the plenum breather gallery, flame trap and LH rocker cover breather filter

8 Ensure the throttle disc(s) is correctly seated at idle to prevent idle speed hang-up and that the whole throttle mechanism is free of unwanted friction right thro from accelerator pedal to throttle pot. (Note - items 6, 7 and 8, Plenum actions are best done on the workbench).

9 Set the AFM CO content at 1.5%, the mid point of the preferred setting for the Rover SD1 Efi system and reset the idle speed to about 875 rpm, give or take.

10 Set the throttle pot residual voltage to 325 millivolts.

11 Verify the fuel pressure operates in the range 26 to 36 psi. not more, not less.

12 Check the integrity of the plenum and all its air/vacuum hoses for rogue air-leaks.

13 Check all Efi loom wiring and connections for faults/corrosion including the Efi engine earth AND the engine earth strap.

14 Check and replace fuel filter if necessary (also make sure the fuel tank is not emitting crud).

15 (If the Plenum is removed for cleaning) consider lifting and cleaning the injectors, replacing the filter baskets and pintle caps.

None of the above will add anything over and above the engine performance that was not there when it was new.

To improve performance beyond its original spec there are three relatively simple things to do.

1 Fit an upgraded adjustable ECU available in the aftermarket.

2 Fit a rising rate fuel pressure regulator that may give a bit more oomph at the top end.

3 Fit a sports exhaust system that has the effect of improving the overall breathing and minimising exhaust system losses, as opposed to simply adding power which is not possible.

Because you are a newbie you may want to consider some reading material on any of the above suggestions, component by component. If so, trawl thro' my website for the needed information.

Good Luck.

[jrv8]

Hi,
You have a pm.
regards
Jim

[oflynno]

thanks for that guys

the v8 i have is in a range rover 1985
thanks for the 15 tips on improving the engine performance

unfortunately i blew the arse out of the exhaust and left woolly exhaust baffle all over the place

then i took off the front prop shaft and today i took it for a test drive
the engine isn't hunting since i cleaned out the mushroom and the other yoke on the inlet plenum
the engine does cut out though every now and then but i think its just the throttle needs a tweak on the idle setting

jrv8,i came across a rover sd1 today while not looking for it
its a sd1 2000,i arseume thats the older 2litre engine,not a v8 and the gearbox is a manual but the guy wasn't sure whether it would fit my 3.5 engine

are the bellhousings the same?
what should these cars be worth,entire

thanks again for the push in the right direction

[ChrisJC]

The bellhousing will be different, and I expect the gear ratios to be different too.

Chris.

[oflynno]

The bellhousing will be different, and I expect the gear ratios to be different too.

Chris.

ARSE!