Missing, gets better after driven hard...? Any ideas what it could be?

[Deaf Cat 0]

Hi,

I wonder if you maybe able to help.

 

I fancied a little more acceleration than my 174k mile 1.9TD somewhat economical but slightly knackered Sharan, I ended up with a 54k mile 1998 2.8 Sharan :-), it was slower than my plodding TD ?? but had a new MOT and was not rusty!   I don't mind a little simple maintenance so thought it would be a nice little project to get some power back.

 

First I changed leads, slight increase in pulling power and less missing for 2 days and then it dropped back in performance,

Coil pack, again slightly better for 2 days and then dropped back,

Cam sensor, biggest improvement yet, only missed around 2k, 3k, 3.5k and 4k rmp once fitted, improvement in power once again dropped back after 2 days..??? 

Lambda same, slight improvement and then 2 day rule kicked in ???

Poor thing then started to have starting problems so tried temp sensor, and MAF, that cured that.

Crank sensor, helped more.

 

Eventually running with no missing and no 2 day revert back towards lower power..

I don't get this 2 day run better and then then reduce in power thing?

 

Anyways, no missing for around a year now, most of my driving is done around town so maybe I should have stuck to a TD, far more economical Ooops!

However when the road is clear 2.8 is far more fun :-D

 

I have noticed the first time one plants ones foot, through the gears not a lot happens acceleration wise, its ok but not fab.  On the same journey plant ones foot through the gears for a second time the response is far better.  3rd time and is lovely.

Seems to be a pattern, sometime its fine, other times it seems to need a bit of boot through the gears to wake it up.??

 

It has just started to miss and does not start first time here and there, it was missing really quite badly accelerating through the gears the other day pulling away from the lights, but the second time one sped away it was fine and fast..??

 

So in summery it has been fine for a year, it has started to miss again, but seems a good boot through the gears to wake it up ??

 

Any ideas?

 

I am thinking I should find the ECU and clean all connections especially the earth one..??

 

Cheers for any comments!!

 

 

 

 

 

[p0u1 14]

I wish replace the coil pack, there not a good design, iv had a few ICM go on me.

[MylesPerHour12 0]

I actually did this v6 mustang coil pack swap on my 12v vr6 and noticed a considerable difference
http://www.roflwagens.com/showthread.php?8271-12v-VR6-Ford-coilpack-swap-(MK4-MK3)

[noggin 29]

It's well worth getting a decent German coilpack, some good HT leads (- I use Magnecour) and some decent plugs. I've fitted these to me last three VR6s and each time it's transformed the car. I'm currently running a tankful of Redex mix to clear the injectors as I previously found some improvement.

[Deaf Cat 0]

Thanks for the thoughts.

 

I am pretty sure I searched out a decent coil pack, I shall check what I installed tomorrow, that has been in around 18 months.

Yes I have Magnecor 8.5 leads, and have been using Shell V-Power for 2 years now to keep things clean...I believe!

Plugs went in 18 months ago, original design spec alternative, seem to remember NGK...

 

Mustang coil pack looks an interesting project.  How can one be sure it is the coil pack playing up?  - Oh I guess watch it in the dark?

I am wary of spending time a money on such an interesting project just in case the problem is somewhere else and still persists.

Smooth running is first priority :-) and then playing after ;-)

 

Do you think it may be worth seeking out the ECU and checking all connections are clean and tight on there?

[Deaf Cat 0]

Just checked,

Beru coil pack,

Pitch black outside, and pitch black when looking at the coil pack..... basic test I guess!

NGK Laser Platinum Plugs.

:-)

[p0u1 14]

If you are close to Bedford UK your welcome to try my coil pack.

 

I'm almost certain that it will be your problem.

[Deaf Cat 0]

Thank you! I appreciate the offer :-)

But i am in East London, a little too far i feel

 

I dìd keep my old coil pack as it was not an obvious improvement when i put the new one on... slight but not obvious...

I may try the old one again, but yesterday it pulled better than it has in ages...??  Weird

 

Can coils be intermittant?

 

I must say it does get rather hot under the bonnet! If they are sensitive to heat its not suprising they fail...who designed that tut tut tut

[MylesPerHour12 0]

I did have an intermittent miss under load on cylinders 1,2, and 5. The misfires were also present whenever I would spray the engine down to clean it and I could see it arcing all over the place, so obviously the coil pack was cracked. Which is what made me decide to replace it and hope that it was the cause of the miss under load. I did some searching around for a more reliable coil pack when I ran across the mustang coil pack swap. I also work at a Ford dealership in the US so the parts were easily accessible, so I figured why not try it. I was amazed at the difference it made. The misses were gone completely, and the throttle response was amazing. I do agree with your thought of trying to get it running smooth first, and I'm not sure that it would fix your issue. But if your going the route of a coil pack, I would definitely recommend going for mustang coil pack because of how cheap it is and how much of an improvement I felt. When I was testing it to make sure it would work, I didn't cut the brackets or anything so I could reassemble the original coil pack if I needed to. And I could post pictures of my "temporary" upgrade if you're interested

[Deaf Cat 0]

I must say, I have had a little browse, just out of interest, for one of the Mustang coil packs, as reliability would be great.  However they do seem somewhat tricky to find, let alone get one to the UK.

 

Yes please, MPH12 if you do have a pic handy of your temp upgrade I think it would be worth seeing, just in case I do find a Mustang coil pack.

 

Since I posted we have had, rain, frost, hail and sun, all of which I don't seem to be able to connect to any performance change, I know the car likes the cold, that is easy to tell, but as for the missing, it's reduced somewhat since posting...???  arrr.. but I have had to turn the key twice on two occasions, as it did not catch the first time... hmmm.

 

It has it's MOT Tuesday so I shall ask if they can plug it in, see if any errors come up, also if there are any other air sensors that could be changed...?  

 

Any pointers on where a Mustang coil pack could be bought from may well be of interest! :-)

 

Cheers

[p0u1 14]

On 17/02/2018 at 6:24 PM, Deaf Cat said:

I must say, I have had a little browse, just out of interest, for one of the Mustang coil packs, as reliability would be great.  However they do seem somewhat tricky to find, let alone get one to the UK.

 

Yes please, MPH12 if you do have a pic handy of your temp upgrade I think it would be worth seeing, just in case I do find a Mustang coil pack.

 

Since I posted we have had, rain, frost, hail and sun, all of which I don't seem to be able to connect to any performance change, I know the car likes the cold, that is easy to tell, but as for the missing, it's reduced somewhat since posting...???  arrr.. but I have had to turn the key twice on two occasions, as it did not catch the first time... hmmm.

 

It has it's MOT Tuesday so I shall ask if they can plug it in, see if any errors come up, also if there are any other air sensors that could be changed...?  

 

Any pointers on where a Mustang coil pack could be bought from may well be of interest! :-)

 

Cheers

 

 

You can get a copy of the original coil pack for under 40 quid if you look about, I think my neighbor got his from BEDFORD batterys.

 

If your looking for the real bullet proof Idea look for msd coils running through the original ICM.

 

 

[Deaf Cat 0]

p0u1 - Cheers

 

Update, Car went for MOT, mechanic said they test drove it twice during the day, and it is a lovely drive, almost hinting, as to, what am I talking about?

 

And it has been driving lovely since....

 

No error messages showed up on the garage computer.

 

Ah, the day after the MOT the ABS light came on, and stayed on, I called the garage and asked if I could pop in on the way past, and for them to plug it in quick, to see if it registers the ABS fault.

They could not get any information up as it kept saying 'communication error' which to the garage owner, ment it could well point to a ECU problem.. but it drives lovely so keep using it!, hopefully the ABS light will just go out, which it did when I drove off...

 

So intermittent faults of missing and ABS, could this be an ECU issue? the car is probably only worth £600? and ECU correction or renewal could be around £1k...

 

The choices we have a!  hmmmm

 

Still,  :-)  another years MOT on my 21 year old VR6   Werhoo! :-)  

[Deaf Cat 0]

Missing has now started to come back just now and then...

Twice I have had to turn the key twice to get it started...

And.. in the freezing weather there seems to be a electric saw kinda sound from the opposite end of the engine to the coil pack.. once reached temp the sound goes.. weird.. now the weather has warmed up a bit, no electric saw sound..??   I guess could it be an ageing bearing lacking lubrication, but from where?

 

I think the car just likes the TLC that garage gives it :-) They don't actually find a fault but the car is fixed when it returns home..?? Crazy :-)

 

 

[p0u1 14]

Most likely the aux belt tensioner.

 

I replaced the bearing in mine for 4 quid.

 

To do this you need to remove the bearing from the pulley and to do this you will need to remove some of the lip off the hole that the bearing sits in.

 

I used a Stanley knife it works well.

Edited March 16, 2018 by p0u1

[p0u1 14]

For reference  http://forums.fourtitude.com/showthread.php?7074588-Longitudinal-VR6-24V-belt-tensioner-question#/topics/7074588

Edited March 16, 2018 by p0u1