chris.s.j.todd

hi, all. need some help.

lets start at the begining so we all know whats be happening.

it started last sunday (6th april) with the standard fuel pump failing, so i replaced it with a walbro 255. ran fine for two days then the cheep fuel reg failed (looked like an ebay special) so go hold of and fitted an original one. again ran fine until wednesday when when it would start fine but then stall, or start apply throttle it would rev abit and then stall. i and a few others throught that it could be the pump again as when the reg failed the gauge was reading 10bar. so yesterday got a new walbro and airomotive reg, fitted it all and the car started and ran fine, untill today when the same problem is back again.

now the car is stuck at the girlfreinds and not sure what to do next. have a few ideas but don't want to keep throwing money at the problem in the hope it will fix it.

so these are the things that i think it could be:-

fuel filter blocage
maf failed
fuel relay failed
or something else

i know i need to see if there are any code in the ecu which i will try to do later and post up. also faily sure it's not the coil packs etc as only did them mid last year.

any ideas/help would be great

thanks chris

bighead

iTrader: (1)

take it to a specialist ......no worries then

sorry not the answer that you would want

Jolly Green Monster

iTrader: (4)

volt meter on the fuel pump connector pins and see if the pump stops then the engine etc.. check the connector under the seat.. they fail regular..

if it is that.. you kneeling on the seat to change pump could be enough to get the connection good enough again for a few days until you hit enough bumps for it to lose connection again etc..

if not that then check ecu wiring.. if no MAF voltage it will run for a few seconds and then stall.. so check wiring at ECU as could be a lose connection or dodgy wiring mods.

Simon

chris.s.j.todd

hi, thanks jolly.
i had 5 min last night to look at it. watched the fuel pessure, which was fine on idle untill the car started to rough idle and almost stall when the pressure increased by around one bar. this to me looks like the ecu is trying to conpensate for something by increasing the fuel supply, and the pump is working fine?

i've got a mate looking at the ecu codes today and checking the voltage to various sensors and will post the results later.

also need to see if when i put the down pipe on weather i knoked any sensors that could cause this?

any more ideas would help

chris

andyxros

id also clean my idle control valve tip they can get thick oil and gunk on them.
dose it start and not stall if you keep your foot on throttle for a while then let off and it stalls?

Jolly Green Monster

iTrader: (4)

the ecu triggers the pump but doesn't know the fuel pressure.

the engine on idle pulls a vacuum on the vac line to the fuel pressure reg and pulls the pressure down from the static pressure.. as the engine stalls the vacuum on the inlet manifold and therefore vac lines return to atmospheric pressure hence the pressure goes up as the fuel pump is still running.. the ecu then detects the engine stopped and turns the pump off.

Sounds more like wiring issue possibly related to maf wiring by the run and dye.. but would expect a maf fault logged on the ecu

Simon

chris.s.j.todd

hi simon,
the guy i got working on the car at the min carnt find the green and black plugs to get the codes out. the car is a 95 wrx import would the connectors be in a differant location or colour?

chris.s.j.todd

andy the car stalls with or without using the loud pedal.

andyxros

sorry, dont think it will be what i sugested then. sure the plugs are in same place just might be taped up or high up the stearing colum

scoobyhunt07

ahh this is same problem as mine, but mine wont start at all now!!!!?

its also a 95 wrx import

chris.s.j.todd

well just got a call from my mate and with the test plugs connected the ecu light just stay on. not sure what to do next. he's about to phone simon aka jolly green and see what he says. will let you know.

scoobyhunt07

any updates would be good chris.

chris.s.j.todd

scoobyhunt have you had any one look at it yet?

if so what ideas did they have?

chris.s.j.todd

ok just heard back from my mate apparantly the ecu light permantly on is a major fault, so got to wait till a specialist can look at it. will let you know when they have.

scoobyhunt07

I have had a guy looking over it ove rlast month or so.

had a new fuel pump fitted as that faled a few weeks before.
we have tried maf, timing, crank sensor, coolant temp sensor, test plugs, injectors, i am getting fuel and it just wants to turn over but just doesnt start!!!!
so so so puzzled now

chris.s.j.todd

have you tryed to see what codes the ecu has init? or what the check light does?

otherwise it sound the same as mine, except mine still starts for now!!

scoobyhunt07

Update on mine. we flushed all the old fuel out and took plugs out and cleaned them, Then out some fresh fuel in.

Now it starts, but stalls after 4-5 secs. (Same everytime no fail)!!!

Any idea's?

ECU?

Thanks
JQ

andyxros

(might sound silly) has the vacume pipe come off he FPR? or split,,or maybe a fuel relay is not staying closed due to ecu or warnout. just trying to think of cheaks that dont cost nothing to have a look

scoobyhunt07

sorry to sound thick but whats FPR?

Also how do i check fuel relay?

Glowplug

iTrader: (8)

Fuel Pressure Regulator, just locate the relay and test with a multimeter

scoobyhunt07

cheers b13bat

chris.s.j.todd

had wondered about the fuel relay. the thing with me is the fact the ecu light stays on when trying to get codes out.

harvey

iTrader: (48)

The Walbro pump cannot run at 10 bar as far as I know so there is something wrong here.
Having just replaced a clogged fuel filter I was already monitoring fuel pressure.
During mapping recently I experienced lack of fuel pressure which was set at 3.25 bar over ambient. No problem, just change the SX FPR I thought from my stock of Fuel Labs. The problem showed up about 20 miles back into the mapping session. Must be the pump I thought. No problem. Fit a new Bosch pump. 20 miles later the problem came back and the longer the car was driven the lower the pressure on the guage which is in the cabin.

I then rewired the pump in heavy guage wire with a bigger relay. 20 miles later..............

Eventually the problem was traced to the guage which, after it warmed up started to read progressively low. 2 wasted days!!!

Your problem is not your fuel pressure guage but start by ensuring you have an accurate fuel pressure reading and see what happens to the fuel pressure reading on start up and when the engine dies. To illiminate a number of items you could run a feed from a 12V battery direct to your pump and see what effect that has. Be careful with sparks in the viscinity of the fuel tank. Not a good idea. If after trying all that I would look to borrow a MAF Sensor from a similar car in your locallity and try that.