rough idling/running

[subieboy]

So replaced the radiator after the plastic end tank went boom,

Then the top radiator hose went boom, the back passenger side manifold stud is broken and letting fumes out...

So cleaned the engine both times with water. Now I have the issue where the car is running real rough, When you are driving it almost shudders when you try to accelerate or hold speed.

I think some water may have gotten into the cylinder via that manifold... if so do I pull the spark plug, dry the cylinder and the spark plug and then turn over to eject the water or what??

At a loss here..

Oh and wonder above wonder the heater hose went boom this arvo and dropped all my NEW radiator fluid all over Woolies carpark (at least my car has the same opinion on woolies as me)

[hako]

More probable that water has got into the DFI module or the connector to the DFI. Check the connectors to the DFI and/or remove the coils and check for moisture. Another bit that fails when wet is the oil pressure switch. I'd doubt that water has getten into a cylinder - if it did it would have been ejected pronto.

[subieboy]

More probable that water has got into the DFI module or the connector to the DFI. Check the connectors to the DFI and/or remove the coils and check for moisture. Another bit that fails when wet is the oil pressure switch. I'd doubt that water has getten into a cylinder - if it did it would have been ejected pronto.

Thanks for your reply.

What is the DFI module? and where is it?

I have removed the coils and checked/cleaned them, couldn't see any moisture there.

Is the oil pressure switch located under/near the oil filter?

[subieboy]

Did a code log and found 12 & 76.

Code 76 - Air/Fuel ratio variation between left and right banks - so that would fit right in with the fact that the car is misfiring...

So what would be the cause(s) of the misfire?

I have checked the following:
Leads:
Ohm reading passenger bank is between 2.56 and 2.64Ohms (below 15 factory spec max)
Drivers bank is between 3.54 and 3.67 (below 27 factory spec max)
Lead condition, no burn-out spots, pinholes, charcoling/sooting and they are new
Plugs - who knows got to get at them but they were done at the same time as the leads.
Coil packs - no moisture, in good nick (from visual inspection and did a resistance test too).
Checked the oil pressure sensor and some oily substance was pooled there (small amount barely got any onto a cotton-bud) but that could be from when the car was degreased 4 - 6 weeks ago...
The car has a brand new radiator, radiator hoses and heater hoses and coolant to 50% of glycol (because the coolant blew everywhere and the radiator had a looooooong crack in it), engine bay got a good hose down of new coolant then water to clean the coolant away (might be a contributor to current issues??)

Also from driving around today:
When driving with low throttle opening (barely above idle) there is still misfiring, but barely audible, and at idle you can smell unbearnt fuel and a "rotten egg like smell".

When giving it a bit of jandle/right foot, the car hesitates, lurches, sputters, misfires and backfires and sounds like poos generally. But it goes kinda sloooooooow

[hako]

My next step would be to remove and regap the plugs to 1.1mm instead of the recommended 1.5mm. Reason for this is that it makes the plugs fire easier (less gap to jump) and can fix an annoying miss. It cannot harm the car (I gap mine to that and have no probs in 6 years).
Air cleaner didn't get saturated?
Check connector to DFI module under coils - also I'd apply a hair dryer to it so as to remove any traces of moisture. Also pull back the boots on high tension leads at plugs and coils to check no moisture and finally make sure plug lead nipple is fully pushed onto plug.
The above are the possible fixes that cost nothing.
Good Luck.

[subieboy]

Cool cheers...

[Cheap6]

That broken manifold stud and leaking exhaust might explain the code 76 (sucking air and misleading the O2 sensor).

[subieboy]

Ok so over the weekend I replaced all the spark plugs, This seems to have alleviated the miss (audibly) at idle, when labouring/accelerating the miss/rough running is still there.

So tonight I sprayed water all over the leads and this didn't really alter the idling at all and the miss was still present when I revved the engine. No spark/flame/light etc was visible when doing this at idle or revving engine (sorry neighbours).

So would I be correct to assume that its not the leads (tested within limits for resistance and there was no spark or anything visible when wet), but is more likely one of the coil packs or maybe the DFI thingy under the coil packs.

[scozz76]

Test your coils by unclipping (one at a time) the injector leads. Once you find an injector that doesn't make a change in your idle, plug it back in and pull the injector lead on the cylinder that shares the same coil (numbers on your coil pack). If this cylinder isn't firing aswell, it would be your coil pack.

Well, that's how I found the problem with my VS.

[vs95calais]

also an idea would be to change the oxygen sensors on the exhaust Y peice and check your airflow sensor is conected with no water in the terminal after trying these if problem persists change air flow metre if it still persists im sorry but a mechanic might be needed but by the sounds of it i would look into the injectors as well

[Rossbx]

I had problems similar to what you are experiencing now with my VP V6. I changed Plugs, leads, DFI module and coil packs. It seemed a little better after that but then it started again about a week later. It turned out to be the MAP and MAT sensors causing the problem. Try pulling the lead off the MAP sensor and see if it makes a difference. It is mounted on the left side of the firewall (on the VP anyway)
MAT sensor I think is on the air intake tube near the air cleaner. If you pull the connectors off them and it makes no difference, then that could just be your problem. I hope this helps

[Zuicider]

also wet relays

[subieboy]

Thanks guys

I had been thinking one or both Airflow sensors could be the issue laletly (we own a Subaru GTB - loves eating AFM's), so dunno why I hadn't thought of it before

also wet relays

Do you mean as in the relays in the bay (by the overflow tank)?

[subieboy]

So I stuck a Multimeter on both the AFM and the sensor in the airbox, after pulling the afm lead and it didn't change the idle or running.

The airbox sensor reading: 1242 ohm (disconnected), back probed with engine running I got a similar reading.

AFM reading (three prongs top to bottom as it sits in the engine bay). With the leads attached as per below:

• 1 "-" lead
• 2 "+" lead = 720 Ohms
• 3

• 1
• 2 "-" lead
• 3 "+" lead = 1757 Ohms

• 1 "-" lead
• 2
• 3 "+" lead = No reading

I then reversed the process from above (i.e. I changed the "+" and "-" round)

• 1 "+" lead
• 2
• 3 "-" lead = 720 Ohms

• 1 "+" lead
• 2 "-" lead = No reading
• 3

• 1
• 2 "+" lead
• 3 "-" lead = No reading

So am I correct to assume that the AFM is dead? Got similar results (cant remember readings tho) back probing the prongs both with the motor running and not running.

[Cheap6]

For the AFM:

You should have battery voltage at the terminal for the pink/blue wire at the AFM.

The brown/white wire is a 5V reference.

The third terminal will have a frequency output that increases with the airflow rate, switching the 5V reference to earth.

This may help some too:

http://www.memcals.com/pdf/VSV6%20Au...%20Diagram.pdf

[subieboy]

thanks mate!

[subieboy]

So we checked the ignition system...

I decided not to do some of the following suggested methods for obvious reasons:
Spray water on the spark plug leads with engine running
Pull spark plugs off the coils with engine running
Pull injector leads/reattach injector leads while engine running

Luke me local friendly Holden dealer tech - nearly sh@t himself when I mentioned those above BTW

So we did the first thing that is apparently quite common with the VS, pulled the centre coil off, and changed it. One look was enough for Luke to be sure it was dead...

2 min later, new coil, no problems...

AFM readings are a bit dodgy but nothing to worry about at this stage.

[bigmicky22]

hi just wondering if you have found the problem with your car yet? my vs wagon seems to be having the same problem but only seems to do it in (auto) 4th gear sitting on or above 80 klms p/h

[subieboy]

hi just wondering if you have found the problem with your car yet? my vs wagon seems to be having the same problem but only seems to do it in (auto) 4th gear sitting on or above 80 klms p/h

Yep,

It was the middle ignition coil that was bung, just replaced it and she was all good.