AU2 VCT - Slight miss

xp_wannabe · 20-01-2012, 10:26 AM

I cannot for the life of me get rid of a slight miss that my ute has, just off idle, doesnt seem to matter if its under load or not.

I have done the following trying to fix it:

1. New plugs
2. New Top Gun leads
3. New VDO ignition coil
4. Reconditioned injectors (ultrasonic clean, new filter baskets, new o rings etc)
5. Cleaned throttle body and entire inlet tract including K&N filter

The miss is still there! It is 10 x better than before I replaced everything, but there is still a slight hesitation there and its really annoying me...

The spark plugs are Autolite 985's, gapped to 0.9mm as per Jim Mock Motorsport advice.

What else could it be? Is it a computer issue? Fuel somehow?

Thanks, Mark

dieseltrain79 · 20-01-2012, 08:55 PM

Inlet manifold gasket . Try tightening up the inlet manifold bolts , see if they are loose .

Otherwise replace it , its common on the falcoons

rmack · 20-01-2012, 09:30 PM

Have you tried cleaning the Crank Angle Sensor?

xp_wannabe · 21-01-2012, 11:41 PM

Thanks for the suggestions fellas, but today I did the ECU reset (as described on here) and it seems to have fixed the problem.

**SSD-85** · 21-01-2012, 11:46 PM

Quote:

Originally Posted by xp_wannabe

Thanks for the suggestions fellas, but today I did the ECU reset (as described on here) and it seems to have fixed the problem.

I love it when its that simple. Hopefully its the last youll see of that issue.

xp_wannabe · 23-01-2012, 10:40 PM

Actually, scratch that.. The miss is back...

The ECU reset did help, and the very first drive after I did it was nearly faultless (I'm sure I didn't imagine it?!), but now it is back..

How do I clean the crank angle sensor, and where is it?

Do those cheap OBD2 scanners on ebay work on this model?

mik · 24-01-2012, 02:28 AM

in this pic you will see the writing on the harmonic balancer, see the w just above that , the black plastic doover with the couple of wires coming out of it , that is the crank angle sensor(basically a magnetic switch), the harmonic balancer(crank pulley) has a toothed gear type thing attached to the back of it, one tooth is missing on that gear, this is a reference point for the engine computer, the computer counts the teeth from the missing tooth and knows exactly what the crank is doing and when to to set the spark off among other things i suspect.
http://www.olympicmotorwreckers.com....C6E21F626F.JPG
just my opinion , i`d be surprised if it was the crank sensor, but it can`t hurt to try.
i`d probably give it a squirt with a can of degreaser if i had too, i`m thinking maybe you could pull the plugs out taking note which cylinder they came from and see if one looks dirty or different to all the others, if the answer is yes i found one, it might pay to put a working old lead or plug in and see what happens, if it solves the problem you know one was dodgey(it happens on occasion),
if it doesn`t further investigation will be required.

Bushbasher · 24-01-2012, 09:35 AM

Personally I would lose the Top Gun Leads, they're nasty. Value for money would have to be Eagle Leads, I run Eagles on both my cars and don't have an issue and running LPG they're very sensitive to a dodgy lead, and if you've got deep pockets there's Ice ignition leads. Others will have other preferences but none of them will be Top Gun that's for sure.

Bushbasher

xp_wannabe · 30-01-2012, 05:42 PM

Quote:

Originally Posted by Bushbasher

Personally I would lose the Top Gun Leads, they're nasty. Value for money would have to be Eagle Leads, I run Eagles on both my cars and don't have an issue and running LPG they're very sensitive to a dodgy lead, and if you've got deep pockets there's Ice ignition leads. Others will have other preferences but none of them will be Top Gun that's for sure.

Bushbasher

I'm thinking it's the leads as well. The problem has intensified with the recent rain/humid weather we've been having.

I'm going to try the Eagles, and Repco will send the Top Gun's away to be tested, and if they fail they will refund my money.

xp_wannabe · 26-03-2012, 10:23 AM

Ute is now fixed, ended up being the intake manifold gasket.

See my thread here for more info:

http://www.fordforums.com.au/showthr...76#post4189676

mik · 26-03-2012, 07:21 PM

well done.

dieseltrain79 · 26-03-2012, 09:00 PM

Score ;) Same on the wifes Au ghia !

webbiegareth · 11-04-2012, 11:15 AM

Where'd you get the gasket from, how much... and how did you do it? It's fairly easy yeah?

Our AU has a slight miss at idle, it's very random. It's got new leads & plugs, no change... will probably look at the coil pack next, however if it's easy to change the gasket then I may as well do it, since everyone is saying it's very common in the AU's

Maka · 11-04-2012, 11:34 AM

Quote:

Originally Posted by webbiegareth

Where'd you get the gasket from, how much... and how did you do it? It's fairly easy yeah?

Our AU has a slight miss at idle, it's very random. It's got new leads & plugs, no change... will probably look at the coil pack next, however if it's easy to change the gasket then I may as well do it, since everyone is saying it's very common in the AU's

Try the inlet manifold bolts & see if they're loose too, probably need checking once a year. Not hard at all to replace ive done it. If not, yep its the coilpack !

cheers,Maka

webbiegareth · 11-04-2012, 01:34 PM

I see I can pick up a new Bosche pack for $86 off ebay (with free postage), worth replacing it anyway for that price?

I'll buy a 10mm ratchet spanner and try tightening the manifold though... I've had a quick look at other threads and it looks doable to replace the gasket itself, apparently the hardest bit are the bottom two bolts (which they say to do first).

The one thing that worries me as I have some kind of bracket between the 1st bolt at the front of the inlet manifold and the water thermostat housing, so I'm not sure hot to remove the manifold without removing the thermostat housing to get that bracket out of the way?

Does anyone else have that bracket joining them together?

Day-mow · 12-04-2012, 10:59 PM

That bracket is ok. All you need to do is loosen the thermo bolt and undo the inlet bolt and it's good. Make note of what bolts go where. Some very in size and also like a head. Work Ing a circular pattern moving inside out when tightening them up and Itll tighten up evenly. IMO bottem of cylinders 5&6 are very lame. 1/4 " drive Uni joints and extension bars are your friend!!!