Spark plug question?

amiers · 05-11-2009, 05:09 PM

by putting new plugs in a car could it show up a fault in leads/coils/02 sensors? what i mean is the car is running fine with all the old stuff, but by putting in the new plugs it runs rough?

im asking because i have been told this by a Ford dealership service department.

JC · 05-11-2009, 05:31 PM

I'd doubt it. Have you got a scan tool to read the codes with? I used my scantool on my car last week, and pulled codes for the injectors on all 6 cylinders - didn't affect the running of the car though.

If it's not running well on the new stuff, it suggests the plug leads are not quite connected to the plugs properly (or the coil pack).

FreddyDUZ747 · 05-11-2009, 05:36 PM

You havent damaged a plug upon reinstalling them have you,otherwise^^^.

amiers · 05-11-2009, 05:50 PM

as i have said in my other thread, all i did was change the plugs and it will not idle above 400-450 and sometimes cuts out. before the plugs it ran like a dream. i have checked all the plugs, infact went and got another set!

im running out of ideas. at this point im going to go and buy new coils, leads and 02's i have never come across anything like this in 30 years of working on cars!!!!!

GK · 05-11-2009, 06:57 PM

Quote:

Originally Posted by amiers

as i have said in my other thread, all i did was change the plugs and it will not idle above 400-450 and sometimes cuts out. before the plugs it ran like a dream. i have checked all the plugs, infact went and got another set!

im running out of ideas. at this point im going to go and buy new coils, leads and 02's i have never come across anything like this in 30 years of working on cars!!!!!

Somethings amiss here. Forgive me for going over the basics.

The plugs are exactly the same as you had previous right? Heat range and gaps the same? If so something's really odd.

Put the old plugs back in. If they work okay, then you know it's the plugs right?

GK

amiers · 05-11-2009, 07:22 PM

Quote:

Originally Posted by GK

Somethings amiss here. Forgive me for going over the basics.

The plugs are exactly the same as you had previous right? Heat range and gaps the same? If so something's really odd.

Put the old plugs back in. If they work okay, then you know it's the plugs right?

GK

you can say that again! no i didnt get the chance to put the old plugs back in, it was bin day and they were gone!

i went to a lower heat range/ gap plug for the lpg, with those in it wouldnt idle at all. so i gaped them from 0.8 to 1.1 it idled but still very low and fluctuating. so i went and got the exact same plugs that came out and the same gap. and here we are. mind you at one point it went back to normal for about 10 minutes, i didnt touch anything it just started running properly. i then took it for a drive and after about 1 k it started to miss. i brought it home checked all the leads again and went back out. the miss was gone but under acceleration you could feel it surging, got it home and the idle was back to 400.

work that out! P.S the only odd thing was i flattened the battery with all the winding over and since then it goes flat in a day or 2, but i also havent driven the car to charge it properly. when i have run it trying to find the problem it charges up enough to start it a few times.

Mr Hardware · 05-11-2009, 07:58 PM

Quote:

no i didnt get the chance to put the old plugs back in, it was bin day and they were gone!

30 years of working on cars and you haven't learnt to keep the old stuff?
I always keep my old air filter, plugs and leads, rad cap, etc, and soooo many occasions have they come in handy solving all manner of weird and obscure problems.

GK · 05-11-2009, 08:51 PM

Quote:

Originally Posted by amiers

P.S the only odd thing was i flattened the battery with all the winding over and since then it goes flat in a day or 2, but i also havent driven the car to charge it properly. when i have run it trying to find the problem it charges up enough to start it a few times.

Was the battery disconnected at all?

GK

amiers · 05-11-2009, 11:03 PM

Quote:

Originally Posted by Mr Hardware

30 years of working on cars and you haven't learnt to keep the old stuff?
I always keep my old air filter, plugs and leads, rad cap, etc, and soooo many occasions have they come in handy solving all manner of weird and obscure problems.

i know! anyother time i do. however just changing the plugs!!!!!

Was the battery disconnected at all?

GK

yes and i have done an ecu reset

**Stav** · 05-11-2009, 11:18 PM

Go and get a new set of leads.Youve damaged one.

amiers · 05-11-2009, 11:34 PM

well i suppose the only other thing i touched was the plug leads. so thats where i will start.

now what leads to get? i have been told QLD ignition leads are good. i also saw these on e-bay http://cgi.ebay.com.au/Ford-AU-Facl...=item439b27abf9 and have been told genuine leads are good. my leads have a fiber ttpe sleeve over them, should i swap those over?

**Stav** · 05-11-2009, 11:35 PM

One other question.Did you install ngk plugs both times?

amiers · 05-11-2009, 11:39 PM

well they are the only other thing i touched. so i will start there.

i have been told QLD ingnition leads are good for duel fuel? or genuine leads, i saw these on e-bay http://cgi.ebay.com.au/Ford-AU-Faclo...item439b27abf9 thoughts?

also my leads have a fiber sort of heat sleeve on them, should i swap these over or go with whatever the new leads have?

mik · 06-11-2009, 12:59 AM

+1 vote stav has it pegged

amiers · 06-11-2009, 07:54 AM

Quote:

Originally Posted by Stav

One other question.Did you install ngk plugs both times?

yes. sorry to all for the double post. :togo:

**Stav** · 06-11-2009, 12:11 PM

If its not the leads try some bosch plugs.

Mr Hardware · 06-11-2009, 12:44 PM

Quote:

i have been told QLD ingnition leads are good for duel fuel?

Correct. Go for a nice drive up to kallangur and get old mate greggy martin to fit em up for ya

amiers · 17-11-2009, 01:27 PM

ok, put new leads on. car drives like new, but still wont idle above 400 rpm. any more suggestions?

**Stav** · 17-11-2009, 07:58 PM

Ok..remove throttle body and clean the throttle plate..top bottom and idle speed controlller. This has to fix it!!If not do another battery reset.

amiers · 18-11-2009, 06:42 AM

done the throttle body and isc and done a ecu reset. checked the whole engine bay for vacum leaks. i just cant believe this when all i did was change the plugs!

the only thing i can think of now is that as the car hadnt been tuned in 3 years and had sat not used for a year, i have put new plugs in and other things that are old arent working with the new. like im sure the 02 sensors are stuffed.

the only other drama im having at the moment is the battery, it is stuffed from all the starting, but it does take charge when i test drive the car after i have checked things. the low idle was there before the battery played up so i think im grasping at straws.

RG · 18-11-2009, 09:07 AM

Quote:

Originally Posted by amiers

done the throttle body and isc and done a ecu reset. checked the whole engine bay for vacum leaks. i just cant believe this when all i did was change the plugs!

the only thing i can think of now is that as the car hadnt been tuned in 3 years and had sat not used for a year, i have put new plugs in and other things that are old arent working with the new. like im sure the 02 sensors are stuffed.

the only other drama im having at the moment is the battery, it is stuffed from all the starting, but it does take charge when i test drive the car after i have checked things. the low idle was there before the battery played up so i think im grasping at straws.

Have you changed coil packs yet or had a scantool put on it to check them for faults?

amiers · 18-11-2009, 08:36 PM

Quote:

Originally Posted by RG

Have you changed coil packs yet or had a scantool put on it to check them for faults?

no i havent as yet. but why would they be faulty after i changed the plugs?

RG · 19-11-2009, 06:03 AM

Quote:

Originally Posted by amiers

no i havent as yet. but why would they be faulty after i changed the plugs?

Could have been all along.

amiers · 19-11-2009, 08:56 AM

Quote:

Originally Posted by RG

Could have been all along.

dont understand RG. the car ran perfectly, both idle and driving, before i put the plugs in. it drives fine now but when you put it in drive its at about 400rpm. also before like all engines do, you would pull it into drive and when the revs dropped it would idle back up to 650@ and you could feel it, i mean you could feel and hear the isc work, now it just drops and stays.

RG · 19-11-2009, 09:04 AM

Quote:

Originally Posted by amiers

dont understand RG. the car ran perfectly, both idle and driving, before i put the plugs in. it drives fine now but when you put it in drive its at about 400rpm. also before like all engines do, you would pull it into drive and when the revs dropped it would idle back up to 650@ and you could feel it, i mean you could feel and hear the isc work, now it just drops and stays.

Hmmmm odd. The coil packs on the V8's are a known issue and only last 80-100k before giving issues.

I take it you are sure you didn't knock anything hard enough and you've checked all connections to dirt/grime build up. You really need to get this thing on a scan tool and see what it is doing and if any fault codes come up.

A dud battery will cause idle issues so a check of the health of it would be an idea too. You did say it sat unused for a year, batteries don't like that.

amiers · 23-11-2009, 01:07 AM

New battery today and charge test. still idles at 400. getting a scan during the week