any holden v6 gurus out there?

[tuk]

hi
I did the holden v6 conversion a year or 2 ago but the motor ran rough as and was overfuelling (parked it up) . I had another go at trying to fix but thought someone on here may be able to help.

1990 v6 vn motor, was a runner in a car before i removed it.
it starts up but runs rough as and black smoke.
-have checked the injectors and they are good.
-rulled out fuel pump as i had my mates pump and fuel hooked up and still the same.
-
-the car runs idols perfect when the fuel pump is un hooked (no power)? i know it dosent sound right but as soon as you turn the pump on it starts farting around again.
-you need the pump to start it but once its started and you turn the pump off it purs away??
-also there is not much flow out the return line?

could this be down to the fuel regulator

any help appreciated

cheers
Brendon

[Ashohman]

Doesn't sound right EFI needs constant pressure in the fuel rail and the PCM pulses the injectors to open/close letting pressurised fuel out into the cylinder, more pulses more fuel more revs also more air needed.

Seems strange it would run with no fuel pump must be just using up what pressure has been built up at initial priming.

don't know if that model motor has a Throttle position sensor but another thing to check will be attached to the hinge on the butterfly. Google how to test it easy to do with a multi meter.


have you checked the butterfly? is operating as it should.

Checked your spark plugs and leads and wiring to correct cylinders.

Tried another computer because if your is damaged and not sending the correct pulses it could be over fuelling.

Hope this kind of helps unless you have tried these things already

[derk]

could be lots of things making it run rich mate, too much pressure, o2 or temp sensors not working, wrong fuel maps?

[tuk]

could be lots of things making it run rich mate, too much pressure, o2 or temp sensors not working, wrong fuel maps?

just seems weird when the pumps off it runs mint,
was thinking maybe pressure (regulator) or a earth or something wrong

[derk]

might run mint with the pump off but it wont run for long what sort of pump is it have you put a pressure gauge on the rail

[tuk]

very strange but will idle away for nearly 1 minute? using the factory s1 fuel pressure regluator on the factory s1 fuel rails.
my mate has the same conversion (runs a treat)so hooked up his pump, petrol and lines to mine and still does the same.

[Crash bandicoot]

your return line from the fuel rail to the tank is blocked up or resticted. was a common problem with some VL's with the RB and injected 5L in it too. fuel pressure would sky rocket to 400 when it was only meant to be 250 ish. usually a perished rubber hose or chunk of rust in the steel line along the chassi.

undo the return line at the fire wall and run it into a bottle, start it see what happens.

this from a service memo..... obviously not directly related to your fuel system but not an uncommon problem.

The return fuel line inside the tank is connected to a plastic swirl pot, where fuel is continually circulated around the low pressure pump inside the tank. The return line has a sort of jet on the end that causes the fuel to be squirted out, creating the swirl. This appears to become blocked or pinched, thus causing back pressure to build up

[Pedro]

check the fuel lines are connected the right way around, inlet to inlet outlet to out let, also check you do not have a injector wire earthed permanently meaning injectors locked open, you may have damaged the harness while fitting the motor, also check injectors are not jammed open, may have crud in them,

pedro

[pruggerdore]

Just about any of the above. try with fuel cap off as if it isn't venting will build up pressure. change fuel presure regulator if can. when I had my fuel lines around the wrong way wouldnt fire at all.
the engine will start and run with most sensors unpluged runnng on the comp base map but should idle up and down a bit as it hunts for its signals. dont think your engine is getting that far and would be looking at fuel pressure issues. have you got the fuel pump relay wired up. when you turn the fuel pump/ignition on does the fuel pump stop after like 3 seconds which wouldnt do it really as it should return fuel to tank unless return isnt working. try starting it runing as you say without fuel pump when you think it is about to die hit the fuel pump for a couple of seconds and see if it will stay running. what Im saying is mess with the fuel pressure system which may convince you it is that system having issues. also possible the fuel injectors are staying on however it would unlikly run at all and you would smell fuel out exaust big time. I would be first removing fuel line from pressure regulator return and see if anything coming out. easy to knock it when fitting engine as sitting right at the back there.
caution! fuel regulator has an O ring rubber seal easily damaged on it so pulling your mates one off to swap it/test may not go down well for him lol
Is fuel return line big enough.
We have spoken before good mates with steve/one arm wemiss. as are you. have lots of series one bits and engines here.
cheers Clive 0210606695
dam that was to much writing

[tuk]

Just about any of the above. try with fuel cap off as if it isn't venting will build up pressure. change fuel presure regulator if can. when I had my fuel lines around the wrong way wouldnt fire at all.
the engine will start and run with most sensors unpluged runnng on the comp base map but should idle up and down a bit as it hunts for its signals. dont think your engine is getting that far and would be looking at fuel pressure issues. have you got the fuel pump relay wired up. when you turn the fuel pump/ignition on does the fuel pump stop after like 3 seconds which wouldnt do it really as it should return fuel to tank unless return isnt working. try starting it runing as you say without fuel pump when you think it is about to die hit the fuel pump for a couple of seconds and see if it will stay running. what Im saying is mess with the fuel pressure system which may convince you it is that system having issues. also possible the fuel injectors are staying on however it would unlikly run at all and you would smell fuel out exaust big time. I would be first removing fuel line from pressure regulator return and see if anything coming out. easy to knock it when fitting engine as sitting right at the back there.
caution! fuel regulator has an O ring rubber seal easily damaged on it so pulling your mates one off to swap it/test may not go down well for him lol
Is fuel return line big enough.
We have spoken before good mates with steve/one arm wemiss. as are you. have lots of series one bits and engines here.
cheers Clive 0210606695
dam that was to much writing

fuel lines all hooked up the right way as it runs and i can rev the crap out of it but runs rough(definitly smell petrol and blows black smoke like its getting choked) once the pumps un pluged it idles perfect(no smoke or smell) an when its going to die i turn the pump on and sounds like its getting choked again(pressure problem?). i took the rails off / regulator and there was a heap of pressure but once the pumps on there was a weak flow from the return line.
my mate seems to think you only need the pump on to the ingition power as it runs the whole time motor is on. i do have a confusion wire that i will get a photo of.

thanks for your help

[pruggerdore]

Ok oxygen sensor in exaust installed. dont like not having it. Should be Quite a lot of fuel coming out of regulator return. still my guess the issue is fuel pressure. map sensor pipe still on at the back?. same comp and wireing that came with engine/car

[tuk]

Ok oxygen sensor in exaust installed. dont like not having it. Should be Quite a lot of fuel coming out of regulator return. still my guess the issue is fuel pressure. map sensor pipe still on at the back?. same comp and wireing that came with engine/car

i will give you a call tonight if thats ok

thanks

[pruggerdore]

tomorrow night be better out and about now. you work in hastings?

[tuk]

i work in ypuk but i get those parts rulled out then give you a bell if stil no joy

thanks
Brendon