Rough idle 1999 V70 T5 FWD RESOLVED, loose hose Topic is solved

[abscate]

Still getting poor (near not drivable) for a few minutes after the car sits for an hour. I am envisioning water pooling in the bottom of tank but mixing when driving.

Can anyone guide me as to the best way to draw of a couple of liters of gas from the car at rest?

[abscate]

Today's report

Ambient 36F

Replaced fuel filter and drew off one liter of fuel. It looked cloudy, but no phase separation of water.

I pulled all the plugs and all were fluffy black rich.

Replaced with new ones, car stumbled on starting until fuel system primed (5 seconds) then ran great

System reporting 28 mpg at 55mph

[jblackburn]

So replacing the plugs SEEMS to have cured it today or no?

Maybe it was just a case of bad gas that screwed up the plugs. Or maybe a stuck injector flooding a cylinder? Hmm...

[abscate]

Took a chance and ran car from upstate NY to Boston today, total 360 miles round trip. Ambient 36F. Still rough on start up and starting after parking (engine still warm)

No problems at speed from 65-70mph. Getting about 24 mpg Via car computer, about 3mpg lower than before.

I'm ditching my water in fuel diagnosis. The poor running is definitely correlated to start up...I'm suspecting the MAF is acting up during the warm up cycle and then running rich afterwards. I'll be checking threads on MAF diagnosis and r/r.

[abscate]

Okay do need help on two things

1. I searched "MAF clean" and can't find a definitive thread on doing this. I seeing hexane, contact cleaner, as solvents of choice. Can someone point me to the 'accepted method' please?

I'm thinking remove and place on a pad of paper towels and flood it with spray, then let dry for several hours.


2 the Idle Air Control system on my 1999 t5 doesn't match the excellent IAC clean thread below

https://www.matthewsvolvosite.com/forums ... =1&t=47533



Is the 1999 system different?

3 it seems my rough running is linked to some solenoid that pulls in every few seconds with a click. Can anyone tell me what part of the induction system does this?

Click...rough running, ,missing, hunts 300-1000 rpm,.....few seconds, click..smooth idle.

Above 2500 rpm car running well.

[abscate]

I went to clean the MAF with the CRC brand cleaner but coud not get the unt to release from the turbo hose....is there a trick to this I'm missing??

[warcraftjunkie]

Pull VERY hard with a twisting and rocking motion. I was very timid about getting mine disconnected the first time I tried, but found that it pops off with enough of the right movement. Also, extreme cold makes it harder as the plastic is less flexible. I have found that its easier to get it off after the car has warmed up if you are doing this in cold weather. Let it idle till it gets to operating temperature... hopefully there will be enough ambient heat under the hood to soften up the plastic a bit.


To answer your other question, your 1999 T5 has the IAC integrated as part of the Eletronic Throttle body.

[abscate]

I bask in the warm sunlight of your knowledge, Warcraft......thanks!




Back to face the dragon this morning....the weather is approaching spring here so the idle issue is becoming less apparent, but I do want this solved fully before next winter

[abscate]

Latest update

Replaced two coils with cracks
Cleaned MAF with CRC product

Still getting bad bogging, misfiring at idle that clears after 15 minutes of driving......

Will write up MAF cleaning to see if I can get some brownie points here...

[abscate]

Update

Have driven 1200 miles with the rough low idle, good performance above 2000rpm

But car has started to stumble under load, pulling up hills
27 mpg at 65mph

I still get a sLew of codes thrown under the rough running, but the consistent ones are pointing to mixture problems

I suddenly realise I have 145k on the car with original O2 sensors

Unfortunately, I have run out of time to work on her so I have called in the pro help.