V40 T4 (1.9) Misfire / backfire - running rich

[mikeyskona]

Ok. Time for a slight update here.

Took the car out on a longish drive, and kept my eye on all the gauges.
The problem seems to occur mainly when the turbo get's out of vaccum.

As soon as it hits +0 psi it starts to play up.. Not all the time, just most of the time. Could this be co-incidence?.. doesn't seem to be particular RPM that causes the issue (well apart from 5.5K Plus) but certain throttle positions (about quarter to 3rd throttle or more).

i also hear the turbo start sucking at about 2250-2500 RPM under load or 3-3250 RPM at idle (thats when it hits about 0 psi in most cases as well).. does this seem right?

Man i hope my turbo isn't screwed... Otherwise i've just bought a junker i wont be able to afford to repair

[andy_d]

id say it gives you a lot more hoses to check and play "is there a leak" with first, "joy" i know.

trying to remember where i read this,, something about a hose + turbo and the hose collapsing under load,, due to the sucktion on it causing the inside of the hose to crumple i guess and block the air flow.

lemme have a rumage about and see if i can find it (might be totally nothing to do with this sort of problem though)


Edit

appears to be a turbo inlet rubber pipe that it refers to, going either soft or a split/hole in,
symptoms appear fairly similar, "wont rev past a certain point/sounds like bag of spanners"
air box to turbo hose appears to be the main culprit with others, hope its of some help

[mikeyskona]

Lol thanks Andy...

My first Turbo Motor, so i'm not used to having so many hoses to faff about with nowadays.

If it's not a hose, what else could cause it to play silly buggers at that kinda range?.

I don't think the turbo is causing the problem. I had a hunch it was a fueling or ignition issue, not air intake....

But after watching my videos Rick81 says it's not a fuel issue, and i'm pretty sure now it's isn't a firing (ignition) issue, which only really leaves air intake system, or another duff sensor that the ECU isn't picking up on?

It is acting like it's over-fuelling as opposed to being starved, so i dont think my fuel pump is weak, And when it was reporting faults (which it isn't now) it did say i was running rich.

Anyways... I will await response with anticipation... Whoever cures this is deffo in for a few drinks! lol

cheers for all the help so far guys, all of you... If this forum wasn't here, i probably would have got the sledgy out by now lol

[andy_d]

noo not the universal large tool of "fixing"

thats for last resort only... or thursdays.


with the help and advice ive gotten for my s40 from the people on here, both directly and reading others with "that" problem , i try and offer the little help i can to others, theres folks on here know way more than ill ever know about s40's ,,and some that are just outstanding with volvo full stop.

[mikeyskona]

It's My Favourite Fixy Tool .. Came in very handy in my Ford Days! lol

[Baffler]

Originally Posted by andy_d

trying to remember where i read this,, something about a hose + turbo and the hose collapsing under load,, due to the sucktion on it causing the inside of the hose to crumple i guess and block the air flow.

The U shaped hose going from the top of the intercooler rad to the throttle housing is the one that can collapse. The same hose where a lot of modifiers place their dump/blow off valves.

I was just thinking there Mike, maybe your turbo boost control solenoid is sticking? It's located on the rear of the air filter housing. Either disconnect the electrical connection from it or remove the rubber hose going to the wastegate actuator. If you remove the hose be careful when you take it for a spin as the wastegate will stay shut

Easy how you go because if you push it too far you could damage your engine.

[andy_d]

Found On Road Dead, Fix Once Repeat Daily, yups had two of those.

[mikeyskona]

Baffler. hmm.... I have no piping from there to the wastegate / dump valves... But i do have them.... somewhere.... Not quite sure where... I can hear them.. but cant see them, lol....

I have lots and lots of wierd and wonderful pipes, with 1 way valves pointing in all sorts of directions, some in and out of the air intake hose. lol

Also i have no Air intake housing, because the previous person took that off and replaced it with a cheap induction cone.

So finding it might not be as easy as all that :S lol

[Baffler]

It will look like this and have three (5mm diameter) hoses connected to it. The hoses should be marked/banded red, yellow and green. I think it's the red one that goes to the wastegate actuator but I can't remember off hand. If you can't find the solenoid then disconnect the hose from the actuator and see if you have boost.

As I said, go easy as nothing will be controlling the boost level.

[mikeyskona]

Oooh... Yeah... Mine's clipped to the radiator....... and has a whacking great big crack in it!.. Ok.. something else for me to pick up tommorrow then... Just unplug it from the electrics and leave the hoses connected?