Fuel pressure test

[8bit]

I know some cars have a point somewhere on the fuel system you can plumb in a gauge to test fuel pressure. Does the mk1 Leon (specifically the LCR) have one of these?

 

[james.l]

Possibly on the fuel return line??.?....

 

[8bit]

Hmm not sure, it would have to be pre-injectors, wouldn't it? Fuel coming back to the tank would be at lower pressure cos some of it would have been consumed by the engine.

 

[james.l]

Pre injectors then?

 

[Muttley]

It doesn't look like it. Elsa shows a gauge being inserted into the fuel feed line at the pump outlet. The critical parameter seems to be flow rate rather than pressure.

 

[8bit]

Damn, was hoping it would be simple. Thanks Muttley.

 

[drka-drka]

What in dear Christ are you up to now lol

 

[ibizacupra]

you dont check fuel pressure by checking the return line
you check feed line into fuel rail with a pressure gauge T'd in

it should follow boost in pressure terms, starting at its normal 3bar start point.. so 1 bar boost you should see 4 bar fuel pressure

there is no check valve to take this measurement on the 20vt fuel rail on LCR unfortunately








Have you logged lambda correction yet like I previously suggested?

 

[8bit]

you dont check fuel pressure by checking the return line
you check feed line into fuel rail with a pressure gauge T'd in

it should follow boost in pressure terms, starting at its normal 3bar start point.. so 1 bar boost you should see 4 bar fuel pressure

there is no check valve to take this measurement on the 20vt fuel rail on LCR unfortunately

Have you logged lambda correction yet like I previously suggested?

Great, thanks for the info Bill. I haven't had a chance to log it yet, possibility I might manage at the weekend. I'll be sure and post it here if I do.

 

[Gulfstream]

I hooked a gauge up on my LCR and showed steady 3.5bars running off boost and 4.5bars+ at 1bar+ boost.

So LCR has a higher oem fuel pressure regulator?

 

[ibizacupra]

normally 3bar like it says on the fpr itself.. unless someone squezed it to get a little more out of it or the gauge is a little off?

 

[Gulfstream]

Not sure what it say tbo. Will put on my glasses when I get home again. All I noticed it was solid at 3.5 bars.

Perhaps the gauge is exactly 0.5bar off.... Need to do a test on it.

 

[ibizacupra]

I know a trick used by some is to squaeze the top of an fpr to make it a little higher..

not just me needs glasses to read small stuff now then

 

[alias]

It depends on where you want to measure the pressure at. Assuming pre-injector pressure, you could take it from the FIP outlet onto the fuel rail.

Hydraulic pressure is equal inbetween two points (in and out, if you will) so any point should be fine after FIP and before fuel rail assuming there are no other exits (leak off, return etc.). I'm not savvy with how SEATs are plumbed in so take it with a pinch of salt. It should be fundamentally the same as Fords, which I am familiar with.