c20xe missing problems

[L33 LEG]

As most of you know, iv just got my valver nova on the road. the engine itself seems spot on but iv got a few problems with how its running.

At first the gsi pump i was using was very loud and spluttering. the car still drove but you could feel the car, especially in 4th and 5th gear, pulling back and struggling. throughout the revs whilst driving it would also misfire a bit at times.

So i changed the pump with another gsi one i had lying around and the pump is now much quieter. the revs feel smoother and quicker but now as im revving it, when it gets upto about 3.5k-4k it will pop a few times as im accelerating.

Does this sound like a fuel problem? i have just swapped my afm because it was idleing high and was hoping it would solve the misfire, it hasnt changed much though.

I am also aware that i need to fit my spare gsi tank as i dont have a swirl pot in the current tank. am i right in saying that it will just effect the car going around corners or could this be part of the misfire problem?

any advice appreciated :thumb:

[let_nova]

i fitted a vectra 2ltr in tank pump to mine. seem like it may not be getting enough fuel.

i never had a swrlpot and didnt get any probs

[twistysnovagte]

do you have a engine management light coming on the dash atall?
i only ask this as mine has been doing similer but only when the em light comes on.

[L33 LEG]

that's the thing, i dont have an eml lol not yet anyway.

i was thinking that im not getting enough fuel. it misses when im hammering it basically. would you advise putting an uprated pump on then?

[let_nova]

just a /xe intank or a vectra 2ltr intank.

[L33 LEG]

could i not use an external one? they're easier to work on Lol. i take all astras/calibras had intank pumps?

[Nobby]

just use the xe external pump mate

[Jon_nova1]

I say internal is easier!

lift up the back seat and there ya go lol would rather that than get on my back

does it pop then continue accelerating by the way? or just keep popping and stays stuck?

[brainsnova]

^^^fit it under the bonnet then lol

[benton101]

check plugs leads and coil or distributer which ever one you have, maybe injectors mate. Does it keep on splutering after 4k cause if not i wouldnt think its your pump cause it would keep on doin it through the revs pal.

[L33 LEG]

I say internal is easier!

lift up the back seat and there ya go lol would rather that than get on my back

does it pop then continue accelerating by the way? or just keep popping and stays stuck?

my fuel pump is connected around my rear strut brace inside the car Lol so its very easy to change :p saying that though, my mate has a very good point saying that because i have mounted it so far up this is why it is struggling as the fuel has to pump up it.

maybe itl be worth putting it back under the car.

it pops and accelerates agains and keeps repeating that. the revs will go all the way up the range but pops on the way.

[AlexW]

Deffo move the pump, remember its ment to push the fuel, not suck it.

[L33 LEG]

il try it in the morning then. iirc when i put the 1.6 in it a few years ago the bit where the pump is meant to go had snapped off so thats why i located it inside the car. where else can i mount it? :wtf:

[Southie]

Usually the pump is fitted to a bracket under the rear at the drivers side. I have mine attached next to the rear axle and it still works fine. As long as it's lower that the tank then you should be fine.

I'd get the EML working though as you may have a dodgy sensor that is playing up, you don't want to knacker something now you've got it back on the road. ;)

[L33 LEG]

im pretty sure the bracket broke a few years ago. il have a look to see where i can put it.

i know i need the eml working, will be next weeks job Lol :)

[L33 LEG]

cheers for the replies by the way :thumb:

[AlexW]

eml is so easy to wire up, even if its just the once to flash the codes its worth doing. Might tell you the problem straight away, i still think its fuel though.

[L33 LEG]

i put the pump underneath the car where its meant to be and its still doing the same thing :( im sure it is a fuel problem but not sure why its doing it. not sure if its worth getting a new pump to see if that will cure it.

[AlexW]

Buy a spi tank and mpi fuel pump :d

[pikey1986]

could it be crap petrol?

[AlexW]

Doubt it, lee works in a petrol station? lol

[L33 LEG]

lol

the next and easiest thing to test it to fill my tank up and see if it runs any better.

the fuel pump is an mpi one. as said before, i am running a 1.2 tank on at the moment but have a spare gsi tank. i doubt fitting it will solve this problem though.

[AlexW]

I know its a mpi pump, id be worried if it wasnt lol 1.2 tank might make it run out of fuel when going around bends and the like but cant see it being a problem otherwise.

Gay big blocks.

[L33 LEG]

I've just driven this again and the missing is much worse now. everytime i put the throttle down it is popping and missing. i can drive it at lows revs and itl be perfect but as soon as i give it some it drives like crap and when i let go it backfires like nothing ive heard before lol

I need to get this sorted as my other car is out of order due to the weather. The only thing i havnt changed i think are the injectors, could this be a likely cause? Anybody else had a similar problem?

[L33 LEG]

Just done a quick search and somebody had a similar question, he got this reply :


sounds like throttle position issue to me.

Mine did exactly the same when i'd fitted the engine, basically i'd cut a wrong wire on the throttle sensor which should have gone to the fuel wiring which caused the engine to try and die when the accelerator was pressed, when floored it'd miss like hell at about 3-4000rpm

just make sure the tps sensor is set right and is activated when the acelerator is pressed

where is this tps sensor? maybe worth a check.

[AlexW]

TPS is on the throttle body, Black usualy.

[L33 LEG]

Looks like il be nicking even more things off my mates spare engine then Lol. he started off with a full engine last year, i have taken more than half of the stuff off already lol

[Southie]

I'd get the EML working though as you may have a dodgy sensor that is playing up, you don't want to knacker something now you've got it back on the road. ;)
:COUGH: ;)

[L33 LEG]

havnt got round to doing that yet Lol. iv only driven it 3 or 4 times since iv got it out. i really need a day working on it in the garage but my parents complain because it stinks the house out lol they go on holiday this weekend so i think il get my mate round with some spares and wel get everything working perfect. i've had a good look through the search and theres quite a few similar problems and a good few things to test so il get them all done and get the eml working :)