idle problems

[sindo57]

hi guys sorry to be a bother but i really cant figure this problem out. about a week ago i changed the spark plugs on my 86 carrera 3.2, all was good for a couple of days i say 3-4days or so then the idle started to go bad, what i mean is its bouncy it will go up to about 2k rpm then drop down and do some weird things like that. also will driving the car it wont matter which gear or speed the car acts like its gonna turn of. i have no idea what plugs were on before but they were bosch with green letters but not it has the platinum 4 tips on it, and its always had an MSD system on it (previous owner installed it.). all this started to happen after i changed the plugs.

any help would be greatly appreciated (cars been sitting about 2 weeks in my garage )

thank you

[DRACO A5OG]

Hey no bother brother!

Your description is the classic HUNTING of the idle.

1st, I am sorry to say, you need to replace the plugs to OEM Coppers BOSCH or NGKs. I had both 4+ Platinums and NGK Iridiums. Great for modern cars but absolutley not for ours.

I have NGK Coppers and will never ever go back to Platinums or Iridiums.

After you go back to the proper plugs, and it still HUNTs.

While hunting, use a screw driver and tap on the Idle Control Valve (ICV). If she clears up, then you need to remove and clean with carb cleaner and shoot some lube in it. Check the OHMs per Bentley, if needed replace.

I bet it is the plugs but it will not hurt you to clean the ICV, they tend to get gummed up with oil.

Jim

[kidrock]

Originally Posted by draco a5og

hey no bother brother!

Your description is the classic hunting of the idle.

1st, i am sorry to say, you need to replace the plugs to oem coppers bosch or ngks. I had both 4+ platinums and ngk iridiums. Great for modern cars but absolutley not for ours.

I have ngk coppers and will never ever go back to platinums or iridiums.

After you go back to the proper plugs, and it still hunts.

While hunting, use a screw driver and tap on the idle control valve (icv). If she clears up, then you need to remove and clean with carb cleaner and shoot some lube in it. Check the ohms per bentley, if needed replace.

I bet it is the plugs but it will not hurt you to clean the icv, they tend to get gummed up with oil.

Jim

+1.

[Zef]

I need to clean mine every year.....

[Nine9six]

For MUCH more info than you care to read, do a search on "hunting idle"
HTH,

[86 911 Targa]

sindo57

If all you did was replace the plugs, and all of the above posts
do not resolve your issues, check the vaccum lines from
the back of the throttle assy to each side of your motor.

Perhaps one of them became loose/disconnected
when you were replacing the rear plugs.

Having incurred this issue myself, it was quite frustrating.

Please check items 21 thru 24 on the attached jpeg.

Also, if you still have the old plugs, verify compatibilty with new plugs you installed.

You may want to re-install the old plugs and check for your current issues.

If all fails, send me an Email.

So far as the type of plugs, everyone has their credible opinions.

I have used the Bosch+4 Platinum for many years with no issues.

Good luck,

Gerry

[DRACO A5OG]

I agree with 86 911 Targa.

One of my lines were loose so I placed a zip tie at the end to tighten the fitting, even though it wasn't leaking it did not hurt.

I too was a big advocate of Platinum 4+'s that the PO put on but for a $2.99 a plug for copper, I had to be sure. To my amazement it cured a whole lot of issues i.e. back fires, cold starts and even sounded better. Just my observations.

[sindo57]

thanks for all your help guys i changed the plugs to NGK they seem to be doing the job for now. I also cleaned the ICV and it all seems to be working properly , i am going to be driving down to the keys with it tomorrow to see how it goes. hope all goes well i will keep you all informed and i hope this thread can help other people too.

thank you
Sindo

[DRACO A5OG]

So how was your trip?

[rnln]

When I changed my plugs to NGK copper from Bosch platinum, I didn't think it made any different until I remember I used to have backfire once in a while from 1st to 2nd. Now, no more those backfires even those it's minor.
Also, there were twice I had bad missing on freeway. The second time I had it for several days, no more missing since NGK went in (several years now).

[sindo57]

well my trip was OK but i had to make it with another car i made it as far as Miami that's about 15 miles away from home and it started with the same issue i checked all the parts like 86 911 Targa said and still nothing. all im going to do now is wait a couple of weeks to take it to a mechanic so he can fix the issue and give the whole engine a tune up. till then its just gonna sit in my garage.

thank you guys for all your help

[DRACO A5OG]

Damn, sorry to read that. Keep us posted.