V40 T4 (1.9) Misfire / backfire - running rich

[mikeyskona]

thanks for your message andy.. i can't respond tho cause i havent sent enough posts.

Rick. They will be going back tommorrow!...

Just in case they aren't the whole problem, i'll mention this whilst i remember.

I've been driving the car about all day, and i've tuned the throttle right down so full bore is actually quarter throttle (because i kept o-ver throttling it and causing a misfire etc)... anyways.. it's been ok-ish... left it for 3-4 hours and just driven home now. Very cold night here in plymouth... and even warm, the car is running like absolute crap again.. worse than it's been all day.

So, it doesn't seem to like a nice clean crisp night?... i thought it would have preferred that :\.

Anyways..... the plugs might be the whole remainder of the problem...... but if this flags any other issues up to you, i'd like to know.. Best to be prepared.

Also..... Remembering i am just about skint... I want to do a fuel pump as well, as i have no idea how many miles this one has done!... What would you suggest?... I'm not after higher performance, or even something guarenteed to last forever at the moment, I just want to get everything right for the moment until the money starts to flow again and i can look at upgrades

Thanks again guys

Mike.

[Baffler]

Originally Posted by mikeyskona

I've been driving the car about all day, and i've tuned the throttle right down so full bore is actually quarter throttle (because i kept o-ver throttling it and causing a misfire etc)... anyways.. it's been ok-ish... left it for 3-4 hours and just driven home now. Very cold night here in plymouth... and even warm, the car is running like absolute crap again.. worse than it's been all day.

Not quite sure what you mean by "tuned the throttle right down"? I'm guessing you've adjusted the throttle cable? There's no need to meddle with any of the factory set screws on the throttle housing!!!

That misfire must be affiliated with the lambda sensors or unburnt fuel due to the incorrect plugs?

Originally Posted by mikeyskona

So, it doesn't seem to like a nice clean crisp night?... i thought it would have preferred that :\.

Yes, turbo charged engines much prefer dense cold air. A lot could ride on the correct plugs so, as a first step, I strongly suggest you get a set of genuine Volvo ones. They are tried and tested and good for 30k miles. Try Angliavolvo on eBay or our resident main dealer FRF Volvo Swansea (Rufe)

Originally Posted by mikeyskona

I want to do a fuel pump as well, as i have no idea how many miles this one has done!... What would you suggest?... I'm not after higher performance, or even something guarenteed to last forever at the moment, I just want to get everything right for the moment until the money starts to flow again and i can look at upgrades

As a temporary measure you could remove the in-tank fuel pump and clean the nylon filters at the bottom of the swirl chamber. After removing the fuel pump remember to replace the sealing ring and plastic retainer ring back onto the tank, whilst you're cleaning, as they WILL shrink and prove impossible to replace when you come to replace the pump. I would also advise you to replace the fuel filter (if it hasn't already been done?) just to the front of the fuel tank.

[mikeyskona]

Yeah... I adjusted the throttle cable in slack, so i couldn't do more than quarter throttle as anything over that kills it

the fuel filter was on my list of things to do next actually, gonna whack a bit of injector cleaner through my next load of fuel as well just to make sure they're nice and clean, two of the first things i do on any new motor. It will also be having an Oil and filter change very soon (what's the best oil to use on these, Castrol GTX? grade?)

Ta

Mike.

[Terminator]

Originally Posted by mikeyskona

Yeah... I adjusted the throttle cable in slack, so i couldn't do more than quarter throttle as anything over that kills it

the fuel filter was on my list of things to do next actually, gonna whack a bit of injector cleaner through my next load of fuel as well just to make sure they're nice and clean, two of the first things i do on any new motor. It will also be having an Oil and filter change very soon (what's the best oil to use on these, Castrol GTX? grade?)

Ta

Mike.

A good quality fully synthetic 5w30 engine oil such as ***hs (sounds like fooks) Titan XTR or Castrol Magnatec (www.opieoils.co.uk) and a genuine Volvo oil filter.

[T4Rick]

Originally Posted by mikeyskona

Yeah... I adjusted the throttle cable in slack, so i couldn't do more than quarter throttle as anything over that kills it

the fuel filter was on my list of things to do next actually, gonna whack a bit of injector cleaner through my next load of fuel as well just to make sure they're nice and clean, two of the first things i do on any new motor. It will also be having an Oil and filter change very soon (what's the best oil to use on these, Castrol GTX? grade?)

Ta

Mike.

Me personaly i wouldnt have touched the throttle adjustment,just replace the plugs and go from there.

[mikeyskona]

Right.
New fuel Filter, New plugs (my local dealer didn't have any, but i got the £40 a set Denso ones that the local dealer recommended saying they're better than the volvo ones anyway, lol). Still it's not playing ball.
Just got a quote for a fuel pump and it's £250!!

It now idles smoothly, but driving is a whole different ball game.
It behaves a bit better when it's not moving, but under load it's still useless.
I found a bit of dodgy wiring (again), connecting to the coil packs, so i have re-done all that properly with good connections and well insulated, so the wiring to the coil packs is now ok.

Whoever owned this car before me has done a real number on it.

I've taken a video of how it performs standing still, it wont go above 5K RPM without popping and then dieing down. Throttle is re-adjusted ok, and the engine started off in that video at 85C so it wasn't too hot or cold.
Oh and it's running 97 ron, as apart from tescos 99 ron, that's the closest to 98 i can get without a 12 mile drive.

here's the vid: http://www.mikeyskona.co.uk/random/ihatemycar.3gp
it's in quicktime format i'm afraid

I hope someone has some kind of idea, cause this is hurting my head and my wallet

cheers,

Mike.

[T4Rick]

First of all you can get the fuel pumps off ebay for 37 if i remember rightly.I got mine from ebay from a comapany called hrc,there pumps are rated upto 500 bhp anyway,ive fitted mine and they work fine.personaly if you couldnt get volvo plugs i would have got the platinums from partco or unipart.There 23 quid and they work mint for me.Did you pay 40quid?if you did your mad lol.the other thing i noticed with my car is the blue connectors to the coil packs,all the rubber bits inside were falling apart so i binned the blue connectors and conneted them straight to the coil pack with electical tape round them to isolated them they fit like bullet connectors.The other problem that caused my miss fire was the coil packs them selves.If you take the coil packs out and look at the stem to see if there cracked at all.I had this and sorted it out.It wont be the fuel pump restricting you at 5k the video sounded quiet bad.it wont be the fuel filter either.it it was any of these it would just run lumpy or cough if thats the right word lol.Have you tried reseting the ecu?Im not saying its gonna work but worth a try.Id just keep at it.What yr is your motor because my petrol and temp gauge isnt like yours

[T4Rick]

Oh i almost forgot lol.I read alot about knock sensors as well cutting in when the car isnt running right.It affects the whole operation of the car when operating such as retarding timing,idle fuel etc.google it and have a look.

[mikeyskona]

Hi rick. The coil pack has been replaced, and there's no cracks etc in it.
My feeds (which are red and green, not blue anywhere) on the coil packs are also connected straight in with insulation tape.

The car is a 1998 T4 CD Estate, with the computer on board.

Can i reset the ECU without a tool? If so, How?

I had a fault code in the past last garage i went too saying it was running rich (they didn't give me the fault code). Anyways, Re-wiring the lambda sensor properly (which was last wired in just twisting the wires together!!!!) got rid of all the engine lights etc, so i'm assuming the lambda probe is now working ok.

So... If it aint the coil packs, and i know it's not the spark plugs, and if it doesn't turn out to be ECU, what's left? lol

cheers,

Mike.

[mikeyskona]

ooh, and the knock sensor.... i was just reading about that.... can i disconnect it? or will that bugger it up even more? LOL