V40 T4 Issues - retarded throttle, etc

[Kent Canary]

Hello!

Well I've been away from here for ages but can hopefully return to the fold for some views / assistance.

My trusty V40 T4 Auto MY99 is struggling at the moment, and running costs are going trough the roof.

Poor idle

On startup the revs rise to about 1500, struggle for a bit before finally settling. This has improved recently following injector cleaner - it used to turn over for a while before firing, and the idle was up and down, but it now at least holds a fairly steady idle once running.

Retarding throttle

This is the most noticeable and at times scary - the throttle just retards meaning the power is lost briefly. THis is usually soon after startup but even when warm and at A road / motorway speeds, the revs will go down and return. I can feel it in the pedal and at there is no kick down at times - often at junctions.

Gearbox?

A couple of times on pull away, when the throttle has retarded, the yellow 'up' arrow which indicates the 'W' setting will flicker on. Yesterday the rev dip appeared related to gear changes, which I'd not really noticed before. Related?

Fault codes
The fault light hasn't come on at al - I haven't got a code reader (help?) but may be able to find a friendly local that has

Temp Guage
I had the temp sensor replaced a few months ago (causing WOT) which solved that. However, the gauge itself now barely gets above the bottom line. Temp wise though, the car isn't overheating; the heater is fine, aircon works ok - so initially I thought this might just be a gauge problem.

Running issues
It;s drinking. It runs rich, you can smell it, and yesterday I put £20 - it's taken me just 40 miles :-(

Done so far
Passed MOT
Took off and cleaned MAF sensor (ran a bit better after this)
Cleaned spark plugs
Examined IAC valve
Injector cleaner

Possibles issues..?

Thermostat
Temp sensor
Lambda sensor
MAF sensor
Fuel filter
IAC valve

So all in all, I'd appreciate some help / advice. Im strapped at the moment, so a full garage service is out of the question, but should be able to do that next month. Happy to look at lo cost / DIY options for now as am reasonably competent with a more competent mate, plus the competence on this form will hopefully get me through, at least until then.

PS am based in Rochester, Kent if anyone has an OBDII reader I could borrow, please.

Look forward to troubleshooting with you!

KC

[JUDGENINJA]

I'm guessing that you've will have done all the basics first, plugs, filters etc before you start fiddling??? I had a bad experience with my ignition coils as I bought one to trouble shoot with, but it turned out that they really needed to be replaced in pairs (thanks RT)

[mitchyboy01]

I would say get the codes read first before you waste any time, effort or money. My car previous car showed a lambda fault and was running badly so reading the codes saved a lot of guess work. Most independent garages should have a code reader and it's a 5 min job to check.

From what you have written it sounds to me like your thermostat may have stuck open. This would cause the car to struggle to get up to full operating temp in this cold weather. Your coolant temp sensor will tell the ecu the engine is cold and chuck a load more fuel in! Your list of possible causes looks spot on though, could be more than one fault causing the bad running. Good luck.

Let us know how you get on mate.

Thanks, Mitch.

[The-Les]

I'm down near canterbury and have a load of spares, including a pair of ignition coils, fuel pump, filter and fuel pressure regulator amongst others. if you get stuck or need bit on the cheap as they are gathering dust give me a shout.

[Kent Canary]

Hi everyone, that's brilliant, thank you for the responses. I've been offered a p/ex for it as another option, so am looking to take that rod which saves me the issue of resolving the faults- if that changes I will let you know, it may be an unanswered mystery but am grateful for the advice and offer of parts. it reassures me I was thinking along the right lines too.

I'll update, particularly if I get a shiny Volvo to replace it :-)

[Alan M]

Buy yourself a thermostat for £5 from ebay and change that. Your thermostat as mentioned earlier sounds like it is not operating properly. All it takes is some torx sockets and draining the coolant and you can comfortably change the thermostat at home no problem without to much know how. Sealing the thermostat housing maybe just about the hardest thing to do which is probably an exageration on hardest lol. Try that first and check your fuel consumption then. Your running issues sound like the car being in a situation where to much fuel is being used/supplied because of an issue somewhere- most likely the thermostat and for under £10 isa cheap repair.