Contour Enthusiasts Group Archives Forums Modifications Zetec Performance fuel pressure

hey guys just a question on fuel pressure

i have 2litre mondeo currently running the following mods:

cat back exhaust
hi flow cat
udp
aem cia with blitz filter
stage 2 crower cams
60mm tb
adjustable fuel regulator

my question is what kind of fuel pressure should i be running at to make my mods run well, at the moment its on 2.2 bar (which is for a standard mondeo i think)

also, after fitting the cams the idle is pretty rough just wondering if anything can be done about that?

thanks guys

Um, when you install a camshaft(s) with more lift and duration, you make the engine run less efficently at lower rpms. Hence your rough idle. If you would have checked with the manufacturer of your product you would been told that idle quality usually goes in the toilet when using a more radical camshaft. Fuel pressure wouldn't have any play with that.

oh i see, its just over at focaljet one guy said that his crowers dint really effect his idle so i got a bit worried even though its not too bad

here in the uk we have emissions testing does the poor idle effect emissions?as i've got a hi flow aswel its getting me a bit worried

With adjustable cam gears you can adjust cam timing to improve cylinder pressure (and torque) at lower rpm.

Two things that will improve low end torque (and idle) are advancing the intake cam and reducing intake-exhaust valve overlap.

I would suggets advancing the intake cam +2 to +4 degrees while leaving the exhaust cam as installed. This efectively reduces overlap by +2 to +4 degrees. Once you are satisfied with the idle you can adjust the exhaust cam to give good top end power.

You may initially that +4 degrees advance improves idle, but you might want to retard the exhaust cam -2 deg to tune the top end. After retarding the exhaust cam, you might find +2 degrees advance on the intake is sufficient, giving a good balance of idle, low end torque plus power past 5000 rpm.

thanks for the very useful info dude im really after power between 3.5k-5.5k rpm as i dont go past that point really

would i be sacrificing the idle if i were to do that?

I just got finished upgrading my fuel pump and FPR. At Idle with the vacuum hose connected to the FPR, I get 32psi (2.2bar). At idle without the vacuum hose connected, I get 40psi (2.8bar).

You can try to run more than stock fuel pressure but your PCM will eventually "learn" what is going on and reduce your injector pulse width to compensate.

If your Mondeo is running lean, you really need to get a chip and have it dyno tuned to properly fix the problem.


HTH,
BP