944s engine hunting when cold

[Guest]

Hi All,

I am now a proud owner of a 87 944s in excellent condition with loads of history and 118,000 miles on the clock. Only problem is that it hunts when cold between 100-1500rpm once its warm all is ok any ideas? any any help would be great

Thanks

Pete

 

[Guest]

hi pete, changing the vacuum lines cured the problem for me, new lines and tee pieces are available from www.promaxmotorsport.com along with lots of helpful info.

steve

 

[big al]

hi

i had the same problem it turned out to be the o-ring seals on the injectors for me

 

[Mikie_gb]

Enine hunting could be one of several things or a combination of several things.

Vacuum leak as suggested. Lots of pipes all over the damn engine. These are easily detatched when fiddling with other items and can also be left detached on reassembley of items. My mechanic left the heater control valve one disconnected at the front drivers side of the engine once.

AFM (air Flow metre). This is a bosch unit situated on the intake duct directly behind the air box on the passenger side of the engine. This unit rather lacks in finesse and also wears out.

AFM adjustment

I have followed the the instructions in the link and it is very simple to do. It does extend the life of the unit, and stopped mine idling at 1200rpm dropping to 900rpm. The AFM costs in excess of £260 for a rebuilt unit, and this adjustment has extended its life some what.

The next item is the Idle control valve, and I have replied to your post else where.

I have done all of these jobs myself, they are pretty simple and make a massive difference to drivability. My 'S' had the added bonus of taking a couple of seconds for the revs to drop on lifting the throttle and played a rather significant role in rear ending someone in heavy traffic. This was also cured by fiddling the AFM as well.