more problems :( starting to lose the will to live.

[jib136]

my s15 slowly seems to be getting more more unrealiable.

sometimes it will boost fine and pull through all the gears but most of the time it splutters alot and feels like it has now power? feels like someone keeps pressing the brakes hard then letting off. also it backfires alot very loud with alot of black smoke on the backfire? when you finally come to a stop it stalls and takes alot of turning over before it starts again.

On idle the needle jumps around alot, the revs will keep dropping then picking up but then eventually stall.

seems to be one problem after another with this car....

ive checked spark plugs, AFM, changed the coilpacks and checked for boost leaks?

what else can i check? ive tried to read my power fc when it does it but everything seems fine?

proper stuck.

any help would be great

 

[Darren_S15]

I could be well off here but have you checked the fueling, injectors, fuel pump etc...

Just a suggestion as it sounds like you have checked all the obvious things...

 

[jib136]

The injectors are 555s and only been flow checked and fitted like 2months ago along with a new turbo :-(

How do I test the fuel pump dude? Thanks

 

[lvaleiron]

get a pressure gauge, check what fuel pressure is (should be close to 2.5 bar on idle), also check the voltage on the pump, for the sound of what you are describing you are just having a small over fueling issue, nothing too bad. if you still using maf, double check (trust me on this one) for boost leaks (all ic piping and vacuum line, everything!!!), you using an aftermarket blow-off? is it recirculating? i had a similar issue and it was a bad plug because the car was over fueling too much because of a leaking blow off, also go to your tuner, check the ecu tune, don't get discouraged by something like that, i've been through a lot on mine, and believe me when i say, when you sort most of these problems, you'll start enjoying your ride a lot. Let me know when you find what was causing the issue.

 

[jib136]

I have got a fuel pressure regulater but it's not fitted yet and that has a gauge on it. Is there a way to check fuel pressure on the power fc? My injector duty is never high so surely that means its not overfueling? I'm not running a blow off valve because that was also causing my problems lol.

Tbh I don't enjoy the car anymore, it just annoys the hell out of me.
Had it over a year and has never work properly?

 

[Jay-pan]

Probably only help a little bit well did for me, I cleaned my idle control valve that sorted my idle as mine would sometime creep around when sitting still. Now it doesn't.

As for the backfire and black smoke its mostly down to fuelling problems, guessing you got a Walbro fuel pump? check its still seated on the bracket correctly mine popped up and kept cutting out, would then like you said take a few clicks of the key to start it again.

I also had when the car was spluttering and backfired loud found mine to be the tiniest cut in a boost pipe. Probs worth getting it smoke tested to see if it is possibly leaking.

 

[pinky15]

back to the maf, I accidently had mine on backwards one time when I installed the intake(newb move I know) anyways it reacted how you are describing.

 

[Sideways Simon....]

is it on standard fuel pump still??

 

[S15_SAM]

Jib you need to take it to a garage. Pro tuner/ Horsham developments. As it sounds like a serious issue! Have you checked compression? Did you swap coil packs over? Who tuned it? Take it back to them!

 

[jib136]

Pro tuner mapped it, coilpacks are fine and compression was only tested 2months ago. It's got a walbro fuel pump mate.

A slight update though because I double checked all the pipe work today and it seemed so I went for a drive. You can build the revs up at half throttle on about 0.6bar boost with it working fine but as soon as you go full throttle it coughs...

 

[shifty]

has a similar thing with my evo....ran like toss for a bit, then started back firing when rev'd from idle, idle started to get a bit lumpy and finally it wouldnt start. Turned out to be the cam shaft sensor. Can you check the ECU for fault codes?

 

[spoonman]

when you say checked the maf, did you just look at it and sprey it with contact cleaner or did you stick a multimeter in the back of the pin to check the voltage, and did you also check the tps voltage

 

[lvaleiron]

I have got a fuel pressure regulater but it's not fitted yet and that has a gauge on it. Is there a way to check fuel pressure on the power fc? My injector duty is never high so surely that means its not overfueling? I'm not running a blow off valve because that was also causing my problems lol.

Tbh I don't enjoy the car anymore, it just annoys the hell out of me.
Had it over a year and has never work properly?

put the pressure gauge and check it, just to make sure the pressure is consistent, also you cannot check it via power fc and even if you injector duty is never high that doesn't discard that you may have a overfueling problem. If you are not running a blow off this also can give you over fueling problem but only when shifting gears or getting of the pedal. Take it to your tunner again so he can check ignition/fueling under hard acceleration.

 

[lvaleiron]

Pro tuner mapped it, coilpacks are fine and compression was only tested 2months ago. It's got a walbro fuel pump mate.

A slight update though because I double checked all the pipe work today and it seemed so I went for a drive. You can build the revs up at half throttle on about 0.6bar boost with it working fine but as soon as you go full throttle it coughs...

Now that you mention about the full throttle / half throttle different, i had a similar problem some time ago, and it was the maf readings were going through the roof when going on full throttle, this maked the ecu thinking that more boost was being developed and dumping a huge amount of fuel into the system making the car sometimes to shut off itself. I needed to crank the car a couple of times before it started again. So you may want to look into this (maf, filter, etc.)

 

[jib136]

thanks for all your help guys!

i had another play with it after work. i took the air filer off and went for a quick drive just to elimate the filter.

it ran awesome!!! pulling at 1.3bar all the way through the rev range no problem.
then i was just crusing home and it started doing it abit again? then it went back to be being normal?

sounds like some sort of weird connection...

 

[lvaleiron]

electrical connections can be a b*tch sometimes... so yeah, checking that is a must!, glad to hear you are sorting your problems bud! patience is the key!!

 

[spoonman]

just get another MAF to check if yours is faulty, people get rid of stock ones all the time to upgrade to MAP's or Z32 meters, so shouldn't be bard to come by

 

[jib136]

Another update!

Car is still poo, stalled on the way home and took a good hour to get it going. The engine was kinda turning over but sounded like no spark or no fuel?

Decided to take it to a garage so hopefully it will get sorted :-(

 

[Jay-pan]

I had that the other day and it was down to fuel pump not seated correctly, what amount of fuel did you have in the car when it cut out?

 

[jib136]

I had half a tank mate, but it doesn't do it all the time?