hi guys..

well i got stage 3 closed loop system, 4x4 tps, greens, t34.48, 3 bar sensor, and all the kit to run stage 3, i took it for a dyno today and ony punched out 310 bhp as the tester didnt want to run it further as the engine was getting dangeroulsy lean at around 4500rpm..before 4500rpm it was running a little rich but then had a massive lean curve..

does anybody know why this could be happaning and how to resolve it?

cheers aaron

 

Can you post AFR's at a few different points so we can see what his opinion of lean was in the first place?

Who's chip is it?

 

its msd chip mate.. got closed loop..yhep il post the graphs up now..

 

When was it setup?

 

today mate

 

heres the printouts the guy gave me.. if you pay attention to the lambda 1 section..it shws it leaning out at around 4500rpm..

 

Fuel Filter

Fuel regulator rising rate

Fuel Lines

Fuel pump

Map Sensor (Unlikely due to leaning out on graph looking like a linear flow failure meaning the pressure is falling off)

 

its got a new fuel pump so could it be the filter or the fuel lines?

its got a new 3 bar..

 

My fuelling issues mainly related to a dodgy Fuel Reg. Has it been changed?

JJ

 

It could be anything that will not allow 350bhp worth of fuel to flow from the fuel tank, through the pump, through teh filter, through the lines and up to teh fuel rail.

It also must do so at 5bar, so the regulator is also a distinct possibility. Have you got a picture to hand of your engine bay?

Do you know what your fuel pressure is set to?

 

standard pressure mate..il get a pic of the bay now and post it up

 

"Fuel pump" includes the wiring to the pump as well of course!

 

well only put a new pump on..havent changed the wiring yet..so isit a good idea to change the wiring?

the car is a 2wd saph regard what it says on the dyno sheet

also it has new greens,..new 3 bar..new fuel pres reg..and new fuel pump

 

Yes, stick it on a relay.

 

As above - put new chunky 12v cable direct from battery to rear (not forgetting fuse by battery), then buy new relay, and use existing supply wire as signal wire.

JJ

 

ok so eplace the fuel pump wiring? on average how long would this take?and what else? as i need the car to be done soonish..

 

Piece of piss mate - takes as long as it takes to run the wire to the rear. Not a hard job - mine took hour max

JJ

 

so basically run a 12v wire from the battrey? or the existing relay to the rear and just conect it into the original wiring at the fuel pump?

 

heres pics of the engine bay stu..

 

None of the normal issues seems to be in existence there, although your "New" Fuel reg having the tamperproof cover missing is a tad concerning...

Does it drive and perform properly off boost?

 

yh it drives fine..comes on boost strong and follows through..

the tester tried turning up the fuel pressure then he turned it back down when realising it didnt do anything..

so whas the best thing to do from now then?

 

and yes drives perfect off boost aswel

 

And he didnt mention it had a flow issue?





Proper cunt, lol

 

lol he stopped the test as it was running to lean..he got upto 310 at 21psi and he didnt want to up the boost more due to it running lean etc.. he didnt know why it was running lean..

dont forget im in australia these cars are rarer then ferrar f40's out here lol

 

Ah, well fair play on the rarity, but TBH same applies to any car if you up the fuel pressure and dont get more fuel!

 

i'm sure if you flew stu out, put him in a 5 star hotel for a few days

he'd tune it for you



as for the previous fuel reg comment, i wouldnt be letting that guy anywhere near the car

 

lol..stu could stay at my luxury home lol..

forget the hotel the house is better lol

dm cars becoming a pain in the ass

 

dont lose faith....they are just the teething troubles of cosworth ownership

you can be happy that you probably own one of the rarest cars in the whole of AUS

 

yh the looks i get makes it all worth wile..

just the cars bein off roas for ages and when i get it done i got this minor problem..

which hopefully if i put a new filter in.. and new wires to the pump should go

 

Easiest place to put the relay is at the rear of the car.

Wire from Battery to new Relay to supply IN of Relay. Put in-line fuse in right by Battery so if the wire chafes, it doesnt cause a fire. Will need to be sensibly sized fuse (to match original requirements of the pump - I think 30Amps will Do it).

There are two wires that connect to the fuel pump - plus and minus. Minus is earth (IIRC). Check that you have good continuity to earth. If not - replace this wire with new strap to good metalwork. Also earthy Relay.

Cut off wire from + terminal. This is now your signal wire. Put this onto the Signal terminal of the relay.

Finally put a good quality cable from the Output of the Relay to the pump + position.

This way, whilst the signal of the original plus cable is not necessarily good enough to power the pump properly, it will be good enough to tell the relay to do so.

Job done!

Then switch car on, and test voltage across the fuel pump with a Volt meter.

JJ



Buy New relay. Put relay in boot area somewhere safe. Many attach to the

 

Graceland did a great write up on rewiring to the fuel pump...

have a search!

Alex

 

https://passionford.com/forum/viewtopic.php?t=174562

 

clearly the tuner was not successful in raising the fuel pressure, even though he fiddled with the regulator. if he had been, more pressure difference across injector = more fuel flow = less leaning out

that infers that either the fuel supply system is not up to the job, or that the fuel pressure reg. does not work in keeping the fuel pressure a fixed amount above the pressure the other side of the injector

as said, wiring should be first easy job along with fuel filter. those should be done on a car of that age anyway.

 

Interestic item this is!

Not want to hyjack this topic but maybe you guys can also give me some info about my graphic of my engine running way too lean on a rolling road session from start all up the rev range?

Here's the printout:

 

Can you two guys not get access to some live data from the management and show us what the injectors are doing under load?

 

Sorry Stu, not having the equipment to get this information for you.
But in my case its all over the range.. Thanks for joining in with you knowledge

Cheers Wim

 

You should club together and buy it.
You could ship teh laptop to each other by DHL

 

Thanks for this bright idea..