I was over with Paul in peterborough yesterday tuning the Megasquirt (very clever guy), but i have a prob, at 4000rpm the car runs out of fuel, the
injectors are fully open but he car still runs lean, which is a shame as it pulls like a train, also under boost it runs lean, so what injectors can i
replace the standard one with ? does anyone know ? (nissan s12et)
or do you think maybe the the pressure reg is buggered or the fuel pump isnt good enough.
[Edited on 29/4/07 by graememk]
Why not do a fuel pressure test and delivery rate test?
i would if i new how to or had the equipment
quote:
Originally posted by rusty nuts
Why not do a fuel pressure test and delivery rate test?
Delivery rate is fairly simple. Just unplug the fuel hose to the raial, point end into a jug and run for 10 seconds. Measure fuel and compare to what you require. For the pressure you need a suitable pressure gauge, which you can attach to the pump and see what it's kicking out. If the engine is failry standard the normal gear should be more than up to the job, so a dodgy pump or fuel regulator could do it.
the only thing thats changed is the turbo thats now a hybid, but atm only boosting around 8psi
Before you go spending money on new injectors you need to find out what pressure you are running.
Get an adjustable regulator with a gauge off eBay. Mine was around £35 from memory. If you are maxing out the injectors them you can just up the
pressure. The gauge let's you know if the range is still sensible though.
If you are using Megasquirt, have you optimized the injector sequencing to get max fuel potential from the injectors, which I think is 2 simultaneous.
just bought one of these ebay button
Different seller but the regulator looks identical to mine.
It works a treat and the vacuum on idle reduces the pressure so I guess with boost you will see an increase in pressure.
i bought it as a guide to see what pressure i'm getting from the pump, the injectors are good for 250 bhp so i'm told, so if the pressures
good it must be the reg. fingers crossed.
The injectors are always rated at so many XXX CC/min @ (a given pressure).
If there Bosch ones then Normally a search of any of the numbers on them turns up the info on the flow rate somewhere on the Net (although a quick
check on Ebay etc would maybe let you know if uprated ones are a common part).
There a an advisory rate of their duty cycle that you should not exceed as that causes probelms with them overheating I believe.
Another way of checking if the originals are upto the job is any articles like "Max Power" or someting more serious, if there's a 200SX
somewhere producing 500BHP on the standard injectors then your problem must lie elsewhere.
i've crossed injectors out as my prob, i think pump or fuel reg
hicost, i've only bought the fuel reg as it has a gauge on it to see if the pump is working ok, calm down my friend, all advice is welcome, i'm not just going to chop off the oem part and bodge on a ebay part just to increase the psi, according to the s12 geeks the injectors i have are fine and suggest checking the vac hose is ok and i have done that so suggests a buggered regulator, which is why i have bought one with gauge on it so it cam be set correctly.
quote:
Originally posted by hicost
Ill cut to the chase, you have read my post, I offered good advice based on you post, Tangoman suddenly discovered what a rising rate fuel reg did which is obvious and useless information.
I wont bother to offer you advice on turbo charged engines again as you obviously don't need it.
[Edited on 29/4/07 by hicost]
IMHO you are all wrong!
A rising rate FPR is one that has a rising rate of pressure if you plotted its delivery pressure against plenum pressure/vaccum.
What you are talking about is a linear rate FPR that can take a positive pressure signal and increase fuel pressure as well decrease it under vaccum.
These are found on most turbocharged cars.