New S4 owner from Northern Ireland

[Darren69]

My money's on the fuel pump at this point. If he is able to check the fuel pressure that will confirm. I think pattern ones are available from Exact Fit and maybe others.

[spuggy]

regulator is there in case of over pressure

A fuel pressure regulator is needed with a positive displacement pump because they don't make pressure without restriction; only flow.

EFI injectors are designed to work best within a given range - and there's a minimum. 3 bar (45 PSI) is the typical spec, which ensures good fuel atomization. More pressure simply delivers more fuel for the same pulse width (a fact often leveraged with forced induction/rising-rate pressure regulators) - but unlikely that pressure being too high would kill the motor - and there'd be obvious signs of it being stinking rich. Low pressure would tend to make fuel dribble out of the pintle rather than delivering a fine mist. and there wouldn't be enough of it.

Sounds possible that either the pump or regulator may not be keeping up with specs at higher RPM. And injectors can get partially clogged with junk.

[Darren69]

So is the symptom of a pump failure or failing pump that you can't rev the bike out past a certain amount of revs? With the mechanism being what it is will it always cut at the same exact revs or could it vary? It sounds as if if would likely be varying by some amount depending on the pressure it was able to maintain under load?

I've never had a fuel pump fail on an injection bike but I've had blocked injectors and fuel rail and it doesn't sound like that to me. It's something else, maybe fuel pressure but could also be electrical or ecu?

Davey, You didn't say if you have a PCIII on there but I'm guessing you will have something similar if you're running a non standard motor?

[Rostrumorhospit]

The one thing the mechanic asked me was if I had checked the fuel pressure, which I haven't, TBH I don't know how, reckon that's the 1st thing he's gonna check.
With ref to the power comander, according to the spec I got with the bike, it had one at some point but it's definitely not on the bike now, allthough the same spec also said it has an upgraded ECU, but I can't confirm this, that's the thing with this type of bike that has a lot of mods your just not sure of the exact spec and factory standard settings might not be applicable.
Thanks again for taking the time to give advice.
Davey

[jerry]

My S4 in Thailand exihibited poor fuel a few times due to clogged filters,, never had a problem with pump but last time i was in Thailand it would not start due to bad pickup cable and disintegrating plastic connectors on efi due to UV in Thailand degrading the plastic connectors until they crumbled ,, so bike was dismantled for repaint and refresh ,, I have collected all the parts in UK at a third of the Thailand prices but cant get back for last 15 months to rebuild her ,, she has a power commander and a DP ecu, termis and airbox mods custom maps and on Dyno now has 115hp

[Rostrumorhospit]

Does the DP ECU stand for Ducati Performance and is there any way of telling what ECU i have fitted.
Cheers
Davey

[slob]

yes DP is Ducati Performance, they're essentially the same ECU with different maps.
I'll try and find an identification link for you

[Darren69]

Rob, Please let me know if your struggling to find anything as I have a couple of boxed ECUs in my spares cache that I can fire off some pics off once I find them. I think Jerry may have some info too since we did some swapsies on the '01 and 02 ECU's

[Darren69]

They're actually also a FIAT part and used on a lot of their cars, if your's is no good it's a cheaper option that the Ducati part.

[slob]

yeah, they're a Webber-Marelli IAW59M/IAW5AM, depending on exact year, Fiat Punto (almost certainly others) of that era uses the same hardware

[Darkness]

Originally Posted by slob

yeah, they're a Webber-Marelli IAW59M/IAW5AM, depending on exact year, Fiat Punto (almost certainly others) of that era uses the same hardware

Could it lead to rust issues if you used a Fiat one?

[slob]

http://ukmonster.co.uk/monster/showp...55&postcount=8

[Rostrumorhospit]

Thanks for that link, some good info on there
Cheers
Davey

[jerry]

My S4 in Thailand has both a DP ECU and a standard one with a PC 3 and my own custom maps ,, which is better than the DP one ..

The DP ECU is great at top end but still rough at slow speeds the Standard one with my PC3 maps is smooth from tickover to 130mph and very punchy on acceleration ,with silky gearchanges .

I may try and get my maps transitioned into the DP one ???? as PC3 makes the loom a bit messy ha ha ,, the critical thing is that the TPS must be set perfectly at 152mv or bike will run badly below 3000rpm .

[spuggy]

Originally Posted by Rostrumorhospit

Does the DP ECU stand for Ducati Performance and is there any way of telling what ECU i have fitted.
Cheers
Davey

Look for a part #. DP ones usually have a sticker, But that'll only tell you what the ECU was when it came from the factory, not what the chip inside has flashed on it now...

This is a good thread: http://www.ukmonster.co.uk/monster/s...ad.php?t=51523

In particular, note Darren's post #5 in the thread; there's 3 types of DP ECU for the 2001 S4 - 100B is for slip-ons/open air box, 200B is full exhaust/open air box and 300B is for cams/full exhaust/open airbox. But the only difference will be the map flashed on the EPROM.

The 2002 S4 has entirely different part #'s.

How do you tell if you have just slip-ons or a full exhaust? Look at the headers. If they look kind of wimpy and under-sized - stock headers. Can't see enough of yours with the belly-pan fitted

There's pictures in the thread of the 50mm spaghetti headers. Pity mine don't look like that...

Just search for the part # you want on Ebay; there's 2 different used 96506100B's just now, and a seller in Italy with a bunch ("More than 10") of new ones.