Jump to content
SAU Community

Recommended Posts

s1 rb25 with a walbro intank, nismo 740cc's, ems stinger map sensored.

can hear the fuel pump priming, starts fine, warms up fine. when warm, idle drops as per usual and still goes smoothly. then driving, you'll clutch in and it'll just die. it still gets on boost fine, doesnt hesitate or miss either. just when you slow down and clutch in it'll die then be a prick to start again. might take a minute or two to get started. it also happens if you just give it a stab of the throttle.

things i've checked/done

-new plugs

-swapped coils

-new fuel filter

-swapped fuel pressure regulator

i put a fuel pressure gauge in before the FPR, was reading at 175kpa at idle, dropped down a bit at ~3k revs and then died as soon as i let off the throttle.

so i replaced the fpr and it went to a fairly constant 200kpa on idle. still dies after throttle though. with the vac line disconnected from the fpr it drops to 180kpa.

doesnt appear as if there are any vac leaks either.

suggestions? dying fuel pump? leaky injector/injector jammed open?

Edited by bj0rn
Link to comment
https://www.sau.com.au/forums/topic/343023-fuel-problemstalling/
Share on other sites

If it's happening consitantly or under the same conditions all the time your best option it to connect it up to a heart monitor(the computer that reads all the magical stuff) and that should tell you whats wrong. Might be a crank angle sensor or something silly like that. Tried cleaning the afm? What fuel are you running it on?

yep same conditions. im not too sure how i'd go about connecting the ems to an obd. i dont have one i dont think i have access to one either.

its map sensored not afm.

its running on bp98 and always has been.

only started happening recently. has been tuned and was running just dandy for a few months up until the other day.

Hvae you had the injectors cleaned?

If you disconnect the vac line from the fpr at idle, pressure should go UP, not DOWN.

It's probably running too rich at idle - lean it off a bit (if you can - after all, you are using injectors that deliver twice what the standard injector delivers). Give it a bit of extra timing below idle rpm, eg if you have it set for 15 deg at 750 rpm idle, give it 17 at 500 and 19 at 400.

Is the "fuel cut on overrun" working, ie does the EMS shut down the injectors when the throttle snaps shut (like during gear changes)?

ok i've completely made an error, i hooked up the fuel pressure gauge in the wrong place. rookie mistake.

it reads a 40psi at idle & 44psi (stock is 36 / 44 i think) with the vacuum hose disconnected. however, it doesnt increase with revs like it should. the dampner after the pump must be a bit f**ked as well because its not a steady flow. the needle jumps around a fair bit.

i'll look for the vac line to the ecu and trace it. otherwise i'll call my tuner tomorrow and see if he can play with the ems.

will report back when i find out what it is.

any other ideas are more than welcome though

Edited by bj0rn

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • It would be well worth deciding where you want to go and what you care about. Reliability of everything in a 34 drops MASSIVELY above the 300kw mark. Keeping everything going great at beyond that value will cost ten times the $. Clutches become shit, gearboxes (and engines/bottom ends) become consumable, traction becomes crap. The good news is looking legalish/actually being legal is slighly under the 300kw mark. I would make the assumption you want to ditch the stock plenum too and want to go a front facing unit of some description due to the cross flow. Do the bends on a return flow hurt? Not really. A couple of bends do make a difference but not nearly as much in a forced induction situation. Add 1psi of boost to overcome it. Nobody has ever gone and done a track session monitoring IAT then done a different session on a different intercooler and monitored IAT to see the difference here. All of the benefits here are likely in the "My engine is a forged consumable that I drive once a year because it needs a rebuild every year which takes 9 months of the year to complete" territory. It would be well worth deciding where you want to go and what you care about with this car.
    • By "reverse flow", do you mean "return flow"? Being the IC having a return pipe back behind the bumper reo, or similar? If so... I am currently making ~250 rwkW on a Neo at ~17-18 psi. With a return flow. There's nothing to indicate that it is costing me a lot of power at this level, and I would be surprised if I could not push it harder. True, I have not measured pressure drop across it or IAT changes, but the car does not seem upset about it in any way. I won't be bothering to look into it unless it starts giving trouble or doesn't respond to boost increases when I next put it on the dyno. FWIW, it was tuned with the boost controller off, so achieving ~15-16 psi on the wastegate spring alone, and it is noticeably quicker with the boost controller on and yielding a couple of extra pounds. Hence why I think it is doing OK. So, no, I would not arbitrarily say that return flows are restrictive. Yes, they are certainly restrictive if you're aiming for higher power levels. But I also think that the happy place for a street car is <300 rwkW anyway, so I'm not going to be aiming for power levels that would require me to change the inlet pipework. My car looks very stock, even though everything is different. The turbo and inlet pipes all look stock and run in the stock locations, The airbox looks stock (apart from the inlet being opened up). The turbo looks stock, because it's in the stock location, is the stock housings and can't really be seen anyway. It makes enough power to be good to drive, but won't raise eyebrows if I ever f**k up enough for the cops to lift the bonnet.
    • There is a guy who said he can weld me piping without having to cut chassis, maybe I do that ? Or do I just go reverse flow but isn’t reverse flow very limited once again? 
    • I haven’t yet cut the chassis, maybe I switch to a reverse flow. I’ve got the Intercooler mounted as I already had it but not cut yet. Might have to speak to an engineer 
    • Yes that’s another issue, I always have a front mount, plus will be turbo plus intake will big hasstle. I’ve been told if it looks stock they’re fine with it by a couple others who have done it ahahaha.    I know @Kinkstaah said the stock gtt airbox is limiting but I might just have to do that to avoid a defect so it atleast looks legit. Or an enclosed pod so it’s hidden away and feed air from the snorkel and below Intercooler holes like kinstaah mentioned. Hmm what to do 
×
×
  • Create New...