Technical Increasing fuel pressure at the TB (SPI cinq)

[ycming]

Hey Peeps,

Done a search and found this thread:

https://www.fiatforum.com/cinquecento-seicento/72415-increasing-fuel-pressure.html

yeah remap is probably the way forward, but I have heard of people with other cars increasing the fuel pressure slightly as this overcomes any reduction in injector performance that it will have suffered over the years, tho getting eth injector properly sonically cleaned returns it to proper flow again, in tank stuff has limited ability to clean an injector no matter what teh claims made by them are.

This should really be done tho with a fuel pressure gauge on the return from the pressure regulator found inside the SPi throttle body top, its at the front of the unit and has a blue wax seal on it, think its a 3mm allen key to adjust, IIRC clockwise for more pressure anticlockwise for less, but with a gague in place then takes away guess work.

Aaron.

So just needs to confirmed it is clockwise to increase the pressure?

Thanks
Ming

 

[Brooky]

yes clockwise

 

[allanhelen]

You screw it in yes, but you have to remove the sealing wax to get a decent purchase with an allen key

also it is trial and error so a bit at a time and try it, if you've gone too far it will cough. fart and backfire

 

[ycming]

You screw it in yes, but you have to remove the sealing wax to get a decent purchase with an allen key

also it is trial and error so a bit at a time and try it, if you've gone too far it will cough. fart and backfire

Ah cheers , yeah got it to turned, the 3mm allen as suggested were too big but 2.5mm fit perfectly.

Not drove the car yet, only done 0.25 a turn. So how do you know when there you have given it enough? What are the signs?

Thanks
Ming

 

[clock34]

mine is fully turned flat as far as it goes and doesnt cough or splutter, tbh i didnt notice a single bit of difference. could my injector be dirty? looks shiney new on the inside.!

 

[allanhelen]

you'll need probably a couple of turns to make any difference and then only if you have a bigger TB

 

[blu73]

You should really put a guage on so you can see how much your adjusting it. Would also recommend an air/fuel mix guage be added while you tweak it and if you can keep it on for a drive around so you can see how your mix is. Go a bit to rich and it'll start choking up your plugs pretty damn quickly (i'm speaking from experience on this one). Once your happy you can remove the guage unless you want to keep it of course.

 

[clock34]

where do you buy said guage and how do you fit it?

 

[arc]

http://shop.ebay.co.uk/?_from=R40&_...fuel+pressure+gauge&_sacat=See-All-Categories

T piece it off the main feed.

 

[clock34]

off the blue petrol pipe in engine bay yeh? can i connect the t peice into the tb and onto the blue pipe so i dont need to cut into it?

im tempted now to put this and a oilpressure guage in my center console.

 

[Italian Coke Can]

I wound mine up a few times with a tricker TB. It went on the RR and was running far too rich. I think it was wound back even further than the original point.

It's a bit of a myth IMO.

 

[ycming]

Half a turn, the car felt so much smoother through the rev range!

But mine did start life as 899, so nto sure if they fuel pressure would be set differently to a sporting?

Thanks
Ming

 

[clock34]

i tried mine in many possitions and didnt notice any difference in driving feel, its currently a quarter turn from fully in, which is about a quarter turn from normal.

 

[mozart]

You should really put a guage on so you can see how much your adjusting it. Would also recommend an air/fuel mix guage be added while you tweak it and if you can keep it on for a drive around so you can see how your mix is. Go a bit to rich and it'll start choking up your plugs pretty damn quickly (i'm speaking from experience on this one). Once your happy you can remove the guage unless you want to keep it of course.

Mate where you put the gauge for fuel preassure ? Is it better to delete the stock regulator and run a malpassi one ? I dyno my car to 92 hp with 1.2 bar pressure and i want to maintain it and check from time to time

 

[blu73]

the stock reg should be fine no worries..
If you want to add a pressure gauge stick it in the fuel line thats going into the throttle body. The reg is maintaining pressure ahead of it - i.e. everything on the fuel supply side from the pump to the reg is what its holding at a regular pressure so anywhere on it is fine but up front where you can see it makes sense.

 

[mozart]

the stock reg should be fine no worries..
If you want to add a pressure gauge stick it in the fuel line thats going into the throttle body. The reg is maintaining pressure ahead of it - i.e. everything on the fuel supply side from the pump to the reg is what its holding at a regular pressure so anywhere on it is fine but up front where you can see it makes sense.

Thank you mate...i had some fuel issues and when i dyno the car i knew that the fuel regulator was at 1.2 bar and the car was going amazing ...so everything that goes of the list is good when you tick problems checked ...