150 replies to this topic

[rik]

it appears I'm running out at 4,000 rpm with 40kpa of boost (about 160bhp )

[rik]

this is why i am having to change to vxr injectors

any chance I could borrow them for a day? too see if it fixes my problem.. or rather move it a bit higher?

[slindborg]

Does the standard ecu fire two injectors every revolution i.e semi sequential so that smaller injectors can be used? Does ms support this?

the megasquirt does fire twice.. or even four times per revolution.. (but it has to be 1+4 at once and 2+3 at once).. which brings me to this:

as we know, the z22se coil pack has the compression sense thing (basically a jumped up cam sensor).. so it's firing the injectors sequentially
but I'm not, I'm firing each bank at once (i.e. 1+4, 2+3)

At these high revs where the injectors are reaching quite a high load, is the difference between firing 1 injector and firing 2 injectors going to affect the fuel pressure in the rail?

if so, then I'm simply running out of fuel (or fuel pressure)

your views please

its possible that your fuel pump is tired if its doing that.
esp if they are failing at well UNDER what the std injectors are rated at.

[rik]

so should be ok doing 2 squirts at once as long as fuel pump is up to scratch? My car's done 80k+ miles and a fair few track days by now

[slindborg]

to be honest, I'd want to see it behaving fine firing all 4 at once!

so yeah it should be normal with 2 squirts.

put it this way, either the injectors you have are dead (but they would be proper dead) or you arent pumping enough fuel into the back of them.

prehaps borrow a pressure sensor to go on the rail and log the voltage from it to get a good clue as to whats going on.

or retro it lol https://www.europasp...GAUGE_2569.html

Edited by slindborg, 02 September 2009 - 10:09 PM.

[rik]

hehe, I've just been looking for a fuel pressure guage actually and thinking to maybe redo the fuel pipes coz theyre all bent out of shape to get them out of the way of the sc belt.. usually I have it on 2 squirts staged (1 squirt from each bank/rev), but it works just as well on 4 squirt staged (2 squirts per bank/rev) (and fails at same point too).. i also tried doing it 1 squirt (1 squirt simultanious) but couldnt get it to start hmm I'll try 2 squirts simultanious tomorrow instead of staged (all 4 injectors firing at once, twice per rev).. if my theory is correct, it'll crap out somewhere over 2000rpm with a bit of load?

[The Batman]

this is why i am having to change to vxr injectors

any chance I could borrow them for a day? too see if it fixes my problem.. or rather move it a bit higher?

sorry buddy I don't plan on buying them until October 5th (remap day) Otherwise you could have borrowed them

[davep24]

hehe, I've just been looking for a fuel pressure guage actually
and thinking to maybe redo the fuel pipes coz theyre all bent out of shape to get them out of the way of the sc belt..

maybe Clutching at straws but have you checked the fuel pipes for kinks?

[rik]

yeah looked as far as I could see without taking the sc and manifold off I think I'm going to replace the fuel lines this weekend to something more suitable

Edited by rik, 03 September 2009 - 11:47 AM.

[rik]

tried a "old style" ford coil pack today (the type with ignition leads).. makes no difference so I put the normal coil pack back on I'll probably use the ford one when I put the saab head on due the spark plugs being deeper on it, I won't have to mess about lengthening the springs

[rik]

at the weekend I'm going to fit new fuel lines

[rik]

fitted... much much tidier... but it hasn't fixed my problem.. exactly the same i guess I'll try vxr injectors next, at least I can always sell them on for not much loss if theyre no good can't find any electronic fuel pressure sensors?? they must exist..

[theolodian]

can't find any electronic fuel pressure sensors?? they must exist..

Yeah, if you're running 150+bar direct injection . . . otherwise cheap and cheerful is more than adequate.

[rik]

but i can't read a analogue guage when im driving along

[theolodian]

but i can't read a analogue guage when im driving along

Sorry, brain fade. I thought you said regulators.

[vocky]

just fit a long piece of fuel pipe to the gauge

[rik]

the fuel lines..
used 10mm for main feed and 8mm for return feed to fit over the existing pipe work
if you do this, be very careful and use special fuel hose clips, not just regular hose clips (they give a better all round grip)







it didn't fix the problem but makes me feel a little better having it all neat and very far away from sc belt

[slindborg]

http://www.omniinstr...600r.id879.html

£120 just for a sensor, but you could feed it into a spare MS input to log

[NickB787]

Wonder if the fuel pump isn't up to it Courtenays are having a number which seem ok but when you ask them to do that bit extra they can't take it. You could make a temp swirl pot + HP pump and try that. I would suggest getting one anyway.

[rik]

do u have a swirl pot nick? pics?