924Board.org

[daddydwg]

I recently was given a 1980 924. Here's the problem:
Sometimes when I try to start it, it fires right up. Other times, it will just turn over until it kills the battery. When it runs the battery down, I can hook up a high-amp battery charger and it will start up immediately.
After it has been running a while and turned off, it will either start right back up, or sputter a little, then start.
So far, I have put in a new battery, tightened the alternator belt,and the alternator seems to be charging ok.
I have limited time to work on it, so any ideas would be greatly appreciated

[John H]

I had a Lotus Europa that used to do this.

We eventually fixed it by changing the coil and the ballast resistors connected to the coil.

Not sure if the 1980'2 924 have the same system but if so, it's worth a try.

[daddydwg]

Actually, I replaced the coil about 6 months ago. Thank you for the advice though.

I should mention, I received the car about a year ago. I just got it running about a month ago.

I took it out on the freeway for the first time last night and noticed the guages working erratically and the lights occasionally dimming. Kind of like the battery was dying and then suddenly coming back to life. When I got home, I looked behind the alternator a little closer, and it looks like some of the wire insulation might be melted. I'm now thinking it might be shorting out sometimes and not charging the battery correctly. Thanks again!

[ This Message was edited by: daddydwg on 2001-12-21 02:53 ]
[ This Message was edited by: daddydwg on 2001-12-21 02:59 ]

[Zuffen]

Two words....ground straps

_________________
Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951

[SpiNko]

Or the voltage regulato could be shot. but my guess is ground straps.

[larso]

I'd vote for the coil resistor/coil spark plug wire, somethign like that. The car will not crank very good with a bad battery strap, and by the sounds of your message it looks like it cranks ok...so something is messed with the spark. Maybe even the ignition module.

[Roger Hall]

My guages fluctuate also and I am going to check the grounds and add some ground straps.

Also pull the fuel pump relay jump the conections (see the Haynes manual) and if the car starts and runs its the fuel pump relay. Simple and cheap to do it fixed mine.

[dpw928]

The bad ground could cause both problems. My 80 924 has two ground straps but only one is mentioned in the Haynes book. One is from the firewall to the head and the second is below the drivers side strut tower and goes to the crankcase. Another common problem is corrosion of the negative battery cable when it is connected to the head (aluminum). A common repair for this set up is to connect the negative battery cable to the body and add another body to engine ground strap.

Dennis

[Sam]

My car had the same problem. The engine would turn over, but it would start when it felt like it, and it would sometimes die for no apparent reason. It turned out being my fuel relay. I also met another 924 fan yesterday who had the same problem with his 924 turbo, and his relay was also bad. try bypassing your relay and see if that makes any difference

[ This Message was edited by: Sam on 2002-01-07 07:37 ]

[TroyDest]

I had a '78 that did the same thing. The problem turned out to be the ground at the back of the car under the hatch, behind the spare tire. The connection (bolt) was corroded and the fuel pump was not getting a consistent ground. Unbolt, wire brush, a little anti-seize...problem solved.

[924RACR]

I had this kind of problem for a long while on the racecar... turned out to be a ballast resistor I added but did not need when installing an MSD coil. The added resistance prevented it from generating enough spark to start. Jumping it boosted the voltage enough to make it work.

This waws diagnosed at the start of a race, stuck on grid while the field took the green. Made it out on track, though, and finished the race!

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[daddydwg]

Here's an update...It's been starting every time I try for the last three weeks!

Here's what I've done so far:
-Replaced ALL of the ground straps, and added an extra from the block to the battery.
-Replaced the intake boot. The small hose coming off the side had broken off, and some mechanic had just stuck a hose into it to 'fix' it.
-I blew out the fuel filter and put it back in (just to see what would happen, haven't gotten a new one yet).
-Cap & Rotor, plugs will be changed this week.
-New Oxygen sensor

So now it is starting, and charging! It has no power when I try and drive it, but I suspect it's the fuel filter (it seemed plugged up when I blew it out). I'm ordering a new filter today.

Thanks to everybody. Without this site, I would be dead in the water (dead in the driveway?) The mechanics that worked on this car when my father-in-law owned it obviously didn't know what they were doing.

[jcope]

Are your guages and lights working better?

[ This Message was edited by: jcope on 2002-06-05 02:55 ]

[daddydwg]

The electrical system seems to be working great.

Also, I forgot to mention that I installed the hose that goes from the front of the car to the alternator shroud...it was not there when I got the car.