2000,S70, Starting Issue

Rbaratt · Post by **Rbaratt** » 24 Apr 2015, 10:13

This started out as an intermittent problem that is now becoming more consistent. When I initially start the vehicle the engine idle begins "hunting" and seems as if it will stall. The condition happens on initial start up, and again after the car has sat for a while, like when I leave from work. I can make several stops going home and then it starts fine.

I thought maybe the fuel check valve, so I always try to run the pump a few times before I crank the engine. This does not seem to help much, and after I re-start a couple of times it will smooth out and I am good to go. There also have been a few occasions when I start up in the morning and it is fine.

No codes or CEL as of yet.

draser · Post by **draser** » 24 Apr 2015, 13:23

Is it worst when cold, better warm?

Rbaratt · Post by **Rbaratt** » 24 Apr 2015, 21:54

happens only on cold starts and seems more prevalent with warmer ambient temps. Coolant temp sensor maybe?

Post by **abscate** » 25 Apr 2015, 04:50

If you are comfortable using an ohmeter there is a complete thread on the ECT resistance readings as a function of temperature available by search, also in the VRD

Search 'ECT resistance temperature measurement'

Rbaratt · Post by **Rbaratt** » 16 Oct 2015, 04:24

I finally got around to putting a fuel pressure gauge at the rail. Pressure is 56psi and holds for many hours after the car is shut off. Turn the key and the pump primes the system to 55 psi immediately. Even when the car exhibited the rough idle (hunting) the fuel pressure was good. I don't think I have a fuel problem, but still no codes and once it clears up the problem doesn't show until it has sat for a while, may 8 hours or so. Not confirmed yet, but it seems on the cooler mornings it is okay but the warmer afternoons at work it has the problem again. I haven't checked the ECC yet, but wouldn't that throw a code?

Post by **Ozark Lee** » 16 Oct 2015, 07:07

The ECT throws a code when it goes open or shorts but in between it really doesn't know if it is correct or not. They can get way out of the proper resistance but still have a valid resistance for some temperature other than what it really is - if that makes sense.

Is this a turbo or a N/A car? Cleaning the ETM might be a next step but on a turbo getting to the ETM is a bit of a bear.

...Lee

Post by **abscate** » 17 Oct 2015, 05:19

Check those ECT resistances up thread.

Rbaratt · Post by **Rbaratt** » 08 Nov 2015, 06:59

Recently when starting the vehicle, and while it was running rough I popped a code PO442 for small evap leak. I wasn't sure if this was "real" so I cleared it, followed by drove several more commutes to work, until Friday when the code returned while driving home. I checked the J hose at the canister but it is in good condition. However further inspection revealed a vacuum line that leads to a check valve, then more vacuum line to what I think is a purge valve. The hose between the purge valve and the check valve had a 4 inch split in it, and looks like it had been that way for some time. I replaced the lines with a couple of dollars worth of fuel line, because the dealer only sells the replacement as an assembly with check valves and hoses for $109. I have only tried to start the vehicle twice since my repair and both times it started fine without any issues.

Could the split in the hose be the cause of my intermittent starting issue? And if it could, why would a constant vacuum leak be the cause of an intermittent starting issue. Of course I still have to run the car for several more days to confirm if the intermittent problem has actually been corrected.

Rbaratt · Post by **Rbaratt** » 08 Nov 2015, 07:09

"However further inspection revealed a vacuum line that leads to a check valve, then more vacuum line to what I think is a purge valve. The hose between the purge valve and the check valve had a 4 inch split in it, and looks like it had been that way for some time."

I forgot to include that this vacuum line assembly and check valve is under the hood at the intake manifold to the purge valve.

Post by **Ozark Lee** » 08 Nov 2015, 08:08

That usually isn't the code you would pull for that hose but any split vacuum line is a bad thing and repairing it will make things better. You will just need to drive it for a while to see if it resolved your other issues.

The J hose at the rollover valve is the "Usual Suspect" for the evap leaks but there are seemingly a zillion places where you can have an evap leak. Smoke testing is the usual method to find the leak if the evap code reappears.

...Lee