The V8 Owners Forum -

is it possible to tune a rover v8 3.5EFI old flapper system?

can the ecu be enhanced in anyway?

oflynno wrote:is it possible to tune a rover v8 3.5EFI old flapper system? can the ecu be enhanced in anyway?

Hello, I'm not sure if you missed this last time around?

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 existed when it was new but you'll be amazed at the horses the above suggestions can release from tired and maladjusted Efi and Injection systems.

To improve performance beyond its original spec there are three more 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.

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 starting with the index here:

http://www.vintagemodelairplane.com/pag ... nts01.html

Does any of this help or appeal, or are you looking for something spectacular?

If so, for bigger bangs with more effect you'll need to increase cubic centimeters and fit a different injection system (not flapper) about which I know nothing!

Ramon
http://www.vintagemodelairplane.com

The flapper systems are very limited due to the odd injectors sizing and the fact that most of them oare well over 20yrs old. A hotwire system can be had for peanuts nowadays if you shop around, with far more easier tuning options!

chodjinn wrote:The flapper systems are very limited due to the odd injectors sizing and the fact that most of them are well over 20yrs old. A hotwire system can be had for peanuts nowadays if you shop around, with far more easier tuning options!

Yup, thats what I had in mind in terms of a more powerful and flexible upgrade, but is it not true that when a newbie says "How do I tune my Engine" what they often mean is "How can I get my engine to run properly?" particularly as in this case it seems the system is not running very well.

So even if/when he upgrades to hotwire etc all the basic work mentioned in my earlier reply (ignition, filters, filthy plenum, air leaks, fuel pressure ad nausium, etc) still have to be addressed otherwise the engine will still run like a crock of &$#@.

strange conclusion from such limited info. He asked how to tune a flapper system; my personal opinion is not to even bother, junk it for hotwire.

I sold a complete reconn'd hotwire system minus the ECU for £100 last yr. But yes, your comments do stand true no matter what anyway!

okay so i'm a bit of a numbnut

i saw the 15 ways to liven up your life and when i looked back i realised i just asked the same question again(Duh!)

right, at the moment the v8 is still sitting in the rangie and is starting and running okay,now the odd time it cuts out but it starts again

i just wanted to see what simple bits i can do,the 15 steps,to improve things without spending the dosh just yet

for example,with modern cars you can feck out the chip from the ecu and put in a new one to confuse it and make it think its a porsche.

but methinks the 1985 flapper system isn't up to this,so i will wait until the engine is transferred into whichever i decide and then look at tuning it when the time is right

thanks lads

more silly q's on the way

chodjinn wrote:strange conclusion from such limited info. !

Because of his other posts - for example: "the pipe was clear but the metal pipe into the rocker cover was blocked with pure black crud" in his prior thread

http://www.v8forum.co.uk/forum/viewtopi ... highlight=

To me that whole thread says his efi system and plenum chamber are very likely suffering from neglect and in poor condition.

Given the info in that thread my reply was not really based on "limited info".

Ramon

Glad you have the time to read everything on this forum. I was going off this post. Dont see why you had to repeat yourself though.

chodjinn wrote:Glad you have the time to read everything on this forum.

I guess thats the advantage of being retired for nearly 2 decades but, honest guvnor, I only read all the thread I am posting in as there is deffo not enought time to read everything

Dont see why you had to repeat yourself though.

Sorry about that! Different thread, people surfing in get the picture in one hit, its a philosophical thing, thinking that when newbies dont seem to get the drift and then ask a near identical question it helps to refocus, one assumes (perhaps wrongly) the threadee will make time to re-read it, they take it or leave it, of course, but then suggesting:

ramon alban wrote: for bigger bangs with more effect you'll need to increase cubic centimeters and fit a different injection system (not flapper)

and you doing similar sorta overlooks the newbie status and the need for a low cost solution before lashing out again.