Possible ETM Issue?

[maxfieldd]

First, I want to say thank you to the community and all of the members here. I have been able to solve almost every issue I have come across with my beloved V70 by lurking here. This place is an amazing resource! This current issue, however, has me stumped.

So... I have a 2001 V70 t-5. Recently I started getting a " engine service required" message intermittently. On the scanner, I found that the long term fuel trim was running rich and decided to replace the front O2 sensor. That fixed the fuel trim and the service message but a new problem came up. The car cold starts fine; then when the car is warm and is shut off, it has trouble restarting. It turns over fine and after about 1 second the rpms start to cycle. The low side of the cycle goes down to about 400rpm and the high side is just over 1000rpm. If I give it a little gas it typically evens out after 5 seconds or so. After it throws its fit, it drives perfect. It happens about 60% of the time after the car is warmed up, then shut down and restarted.

I have cleaned the maf sensor and replaced the air filter. I have also changed gas stations - I always use premium - and added a fuel system cleaner. I also took the ETM out and cleaned it. It was very dirty and the car seems to run better but I am still having the warm start issue. My next step - according to my mechanic - is to replace the ETM with a used one. I am not sure if the software has ever been updated on the existing ETM, maybe that's the trouble?

So my question is, does this sound like an ETM issue? There are some posts here on the forums that sound similar, but I am not feeling "it". Any help would be awesome. I am not afraid to dive in and try things, so suggest away. Thank you all very much! I will post any steps I try and the - hopefully - happy resolution here to pay it forward.

By the way, I wanted to say thank you to precopster, this post started as a private message to him and he responded within minutes. Thank you sir!

-David

[maxfieldd]

I have a new lead. I spoke with a friend that takes apart cars for fun and he recommended I start with the fuel system. He said to test the fuel pump and the fuel pressure regulator and see where it gets me. He asked me an interesting question regarding the sound the fuel pump makes when you turn the key to position 2. He asked if was a hum or a whine. When I went to check it spurred my memory - or maybe it is a false memory based in fruitless hope - that the fuel pump used to be a sort of hum. When I checked today, it sounded more like a whine; just like he said.

So, my journey next will take me to harbor freight to buy a mechanical fuel pressure test kit. This possible explanation makes a lot of sense to me - more sense than a possible etm or tps issue - and I think it could lead to a solution. I also checked out recalls associated with the fuel pump and their are at least two. Maybe if the pump is bad I can get Volvo to put in a new one!

One side benefit of trouble shooting this is by the time I am done addressing this one annoying issue I will have completed my scheduled maintenance. I am also getting to know my car, which is as rewarding as it is frustrating.

[precopster]

If you can recall what the pump sounded like before and you feel it's different now then you may be on the right track; usually nobody knows how the car should sound better than the regular driver.

Checking fuel pressures is a very accurate way of working out if this may be a cause.

Also do a test after it has sat for around 1 hour and see if they have dropped markedly; the fuel pressure regulator that's built into the pump may be the cause. If I'm not mistaken you can implant an aftermarket one inline to remedy the problem if this is the case.

Keep us posted of your findings.

[bobsnow100]

If your car was running rich before and now starts hard when hot , I would look at the fuel injectors leaking.
A leaking injector can cause gas to enter the cylinder when the engine is off and flood the cylinder and cause this hard starting issue.

[maxfieldd]

Thanks everyone. I did not have a chance to check into the fuel pressure issue today - kids school obligations. Good news - kind of - is it finally threw a code today. My wife called me around noon and let me know the check engine light came on. I have bee waiting for some ecm confirmation that something is wrong, so I am glad I have something to work with. I am just getting to checking the code now and will update soon.

[maxfieldd]

So the code it is giving me is "System running rich". It is the same code I was getting before we replaced the O2 sensor. Back to square one...

[precopster]

How's the air cleaner looking?

[maxfieldd]

I think I solved the issue!

After doing all sorts of things - list below - I changed the oil. Last time I changed the oil, which was about 2k miles ago, I used half synthetic. Shortly after I noticed oil everywhere and I started getting codes. This sent me on the adventure I described when this post started. As a last resort I decided to change the oil and not put half synthetic back in. After a few days the pending code is gone and the warm starting issues are resolved.

In case anyone else goes through this I am going to post the list of the things I did here. The original issue was that the car would idle rough when it was started after warming up. After about a week it through the system running rich code - LTFT was around 12.5.

So I:

Checked for vacuum leaks
changed the O2 sensor
cleaned the etm
cleaned the MAS and the intake air temp sensor
checked for vacuum leaks
cleaned the ptc valve and sealed it into the intake with silicone
changed the air filter
had someone else check for vacuum leaks
cleaned the negative pressure valve for the pcv
changed the oil

I hope this helps someone else. I learned a lot about my car and built confidence in my ability to fix it. It was frustrating at times but it was also fun. Thank you all for your help.