924Board.org

datatrain · Posted: Sun May 31, 2009 6:09 am Post subject: Problem at 30 mph

The car starts, first try. Idles fine, no shakes. drive about 1 1/2 miles to the highway no problem. Drive at 80 mph up the mountain so there is quite a load. Come back down at 75 mph and no problems.

Then into town at 30 mph and sometimes it starts to stutter. It idles fine. Pull away from a stop and it stutters. Just going down the street sometimes it'll stutter. Get home and let it idle and it's nice and smooth. Then some times no problems at all.

The fuel pump and filter changed about 3000 miles ago. Plugs last week. The ignition switch changed 50 miles ago for this year. Last summer saw a complete overhaul of the vac system piping and it ran sweetly. The only big change is the new ignition switch this year.

I'm baffled. Ideas are welcome.

Thnx
_________________
'78 924 NA with Collector plate
33 year old car, with me for 21 yrs
Mint '92 318i BMW
Near mint '98 Buick LeSabre
VE7HFR

Ozzie · Posted: Sun May 31, 2009 9:36 am Post subject:

when did you last replace your fuel filter?
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

datatrain · Posted: Sun May 31, 2009 1:02 pm Post subject:

As posted about 3000 miles ago. Today it simply conked out when I turned into the driveway. Started quickly but a bit rough for a few seconds. Started it again later and it was rough running for about 15 seconds.

I'm wondering if the ignition is going intermittent. The tach seems to completely die when it stutters.
_________________
'78 924 NA with Collector plate
33 year old car, with me for 21 yrs
Mint '92 318i BMW
Near mint '98 Buick LeSabre
VE7HFR

RC · Joined: 25 Mar 2007 Posts: 2637 Location: Australia

Nobbi · Joined: 24 Aug 2006 Posts: 1398 Location: Germany

Hi,

take of your distributor cap and check if your vacuum advance is able to move free and easy.Take finger off and add a little bit of oil to the axle under it (should be a little felt that will be soaking up the oil)
And check the vaccum lines to the distributor......
Nobbi
_________________
NA 924 - april/1977- 4-speed-audi gearbox.
500.000 km with fun.....and new toy:Porsche 944 S2 Cabriolet.Other car Daimler c-class cabby,brandnew..Plus : DEUTZ 4005 tractor Built 1967

datatrain · Posted: Mon Jun 01, 2009 5:32 am Post subject:

So Far, So Good !
Inspected the distributor. THere is no way to get to the vac advance with the breakerless distributor HOWEVER... I did pull the rotor and saw a felt oil pad in the shaft. It was a dry as dust. Pulled it out and put some oil in the shaft, soaked the felt and put it back in. It ran much better. The rotor and cap had been on there about 12 years so put on new ones. The road test up the mountain was a complete success.

Thanks for the suggestions.

DAve
_________________
'78 924 NA with Collector plate
33 year old car, with me for 21 yrs
Mint '92 318i BMW
Near mint '98 Buick LeSabre
VE7HFR