2000 S40 2.0T Engine stalling, engine light on, not idling

[rigo3t]

Hi guys,

Today, unfortunately, my car died a little. Here's what happened:

About a week ago, I was driving normally back home and in a traffic light the car switched off. The radio was on at low volume, A/C on on 3rd position, regular driving lights. I quickly switched everything off and moved the gear lever to "P" and attempted to start it. I tried about 3 - 5 times and finally it started up, and I made it home with no further issues.

I thought it was an isolated event so I continued driving it for a week more. Of course, I thought what possibly could be the issue and thought I'd look into it over the weekend.

A week passed, the car behaved normally on highway as well as in normal stop and go traffic. Yesterday however, it started to act up again. The car stalled a total of 4 times, once while going down a hill, and all other three times while being stopped at a light. Of course, by now, I didn't want to play my chances of having to pay a tow truck to take my car to service and be charged astronomic amounts of money for it. I immediately headed home, on the way while going down a hill, the "engine" light came on and the DSA light switched on. If I stop anywhere the engine stalls, period.

Being automatic, you can imagine the journey it was to keep the car on at a stop without it lurking forward and keeping RPMs high enough...

Now, for the symptoms a bit before and after:

Occasionally (it happened 2 times), the idle would "bounce" the car sitting would go from 1.1k RPM to 1.8k RPM... and whenever put on "D" the RPMs would regulate and sustain 1k RPM. (Which is not ideal (862 RPM is the factory idle))

In two occasions in the morning when I started up the car the radio would have "CODE" on the screen, meaning, over night something happened to the power supply.

It seems that the car was prone to switching off when going downhill?

Things I've done:

I cleaned the IAC like two months ago. The car wouldn't hold an idle after starting before cleaning it, and after cleaning it, it was great.

The car has never had trouble starting, not even on the last few days, started right up, less than one second on the starter.

Things I suspect:

Fuel Pressure Regulator?
Intake manifold?
Air filter and hoses to the intake manifold?
Electric problem? Coils? Spark plugs?
ECM?


I don't know where to start and I can't really pour money on my car right now, so going to the dealer is out of the question. I might get a friend to help me out to read error codes.

Any ideas are very welcome, where can or should I start or inspect?

Thank you guys, for your help beforehand.

[difflock54]

Getting the error codes would be a good starting point and might save unnecessary expense.

[FLXC90]

Being a 2000 year-model, does it have the Marelli ETM?, haven't worked on NedCars, yet. If so, that's where I would start.

[Dirk1966]

In case it is an electrical problem:
I read an item on a UK Volvo forum regarding the wiring loom underneath the radiator that can cause some strange faults.

I hope it's ok to add the link , if not then please remove it.

http://www.volvoforums.org.uk/showthrea ... =wire+loom

[rigo3t]

Hi guys,

Thank you all for taking your time to reply to this post and for offering all the ideas you did, I appreciate it.

So I managed to get an ELM 327 and diagnose the car.

This is the diagnostic that it spat out...

P0102 "Mass or Volume Air Flow Circuit Low Input "

and ErrorMIL: On (1) Spark Ignition

So I'm guessing I will start cleaning the MAF out and hopefully it won't be necessary to replace it (I know it's better to replace it). Also I will check out the coils, cables and spark plugs to see if it helps.

I have some interesting readings from the diagnostic, some ideas would help out a lot too.

These are the screenshots



I checked the readings of the MAF as per suggestion of another friend and these are the screenshots:



I took off the MAF and sprayed some electronic's contact cleaner, it did help a little bit in that the car started and stayed on! But it will still die off immediately if I press the accelerator pedal and let go. (Rev it to 1500 - 2000 RPM and let go)

This reinforces the possibility of a faulty MAF. Also, as I remember carefully. A few days before the final failure; if I would be idle at a traffic light, and throw the car into neutral, it would start oscillating from 850 RPM to 1500 RPM and back down and so on, kind of like a sine way cadence. If I would put it in drive it would settle at around 1000 RPM

Then for the coils:

This was a MAJOR disappointment. The coils seem to not be at fault here, which is great, but they are terribly installed... Whichever monkey who worked on my car before I bought it, glued (gray engine sealant) the coil cables to the coil...

Pictures here:



This means when I get new coils I will need to wire them up again with new cables and put the harness endings brand new for the new coils.

I wasn't able to take out the spark plugs to look at them and check the gaps because I don't have a socket extension, I will need to get one. There's also a little amount of oil on the first cylinder (from right to left). Once I cleaned it up from there and cleaned the coils with some contact cleaner the engine light went off, and the car seemed stable but it still stalls if I press the gas and then let go of it.

Also, I see that the (engine cam chamber?... where the cams are) is sealed to the top with that same gray sealant instead of a fine smattering of anaerobic sealer, which could also explain some oil leakage from the cam shaft ends on the right side of the engine.

All in all, not terrible news, but it seems there's a bit more to fix than I'd hope for or have the budget for.

Do these MAF readings seem correct? These where at around 900 RPMS to 1000 since I have to keep my foot on the pedal and that didn't let me have a solid stable reading, although for the most part it's consistent.