924Board.org

50sman · Joined: 03 Jun 2003 Posts: 10 Location: SWEDEN

Hola Dudes.

My 924 runs perfectly for days but suddenly it won't start. The starter runs and the engine is turning but there is no starting.
I can crank for 2-3 min. Nothing happens. If I continue suddenly it starts and runs like if nothing ever has happend. When it starts it goes smooth direcly, indication that there is no flodding och the enging during the previous tries.
If I try to find a common nominator I end up with=heat/warm. It occurs when I try to start when the negine is "semi" hot i.e it has cooled for 10-30 min after last use.
So! I have been reding here at the forum that it might be the "hot start syndrom" and that I can overcome this syndrom by trying to rewire a new ground¨. I can by this but I wonder if this is the solution. Usually when I had problems with my former cars they always ignite to some extent, a puff or similar (if it not was an electrical problem) but the 924 is stonedead, exept for the starter. I expect that even if I have som problems with the fuelsystem the engine would at least puff during my attemts to start or is this "hot start syndrome" so effective that it is all or nothing??

Bye for now
_________________
"Please, please - brake "

1998 BMW 540iAT - "The Jap Killer"
1980 924 - "For making my neighbours ...."
1998 MB E420 - "For lazy days"

Lizard · Posted: Fri Jun 27, 2003 1:57 am Post subject:

make sure your distributor cap isn't getting water or moisture in it, and make sure that the fuel pump is coming on right away, but it defenatly could be the WUR
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3 928s,

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

Even with a toasted WUR he should still be getting a short duration start or stumble, especially with a warm engine. I'd suggest an electrical, or electrical-related fuel problem. I agree though that you need to listen for the fuel pump to come on with the first turn of the key. ...no pump, no fuel, no stumble, and certainly no start. If you hear the fuel pump(s), check for spark. Start with the easy, simple stuff before getting getting deeper.
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'79 Eurospec 931

Alex Roy · Posted: Fri Jun 27, 2003 4:33 am Post subject:

You said it does NOT flood? Fuel pump and relay failure is really common in these cars. I'd look there first.

Phogphire1 · Joined: 05 Apr 2003 Posts: 293 Location: Portland, OR

It could also be the Ignition switch. here is a post regarding it it pretty easy to check, When you release the key trying to turn it over does your Voltage needle drop far left and does your tach drop like when you cut the car off. One of the wires on the ignition controls a bunch of items by send voltage to them, your car will crank but no combustion will take place, because no juice is going to you coil or distrbutor, therefore nothing to you plugs.

http://203.185.241.26/viewtopic.php?p=54143&highlight=&sid=544cdd52d22b23a580c6121d70fa9df6#54143
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Extremism in the defense of liberty is no vice. And moderation in the pursuit of justice is no virtue.

Life, Liberty and the Pursuit of thoose that dare screw with it.

wenchpuller · Joined: 25 Jan 2003 Posts: 50 Location: Vancouver Island

I had the fuel pump side of my ignition switch go last fall. Jumpered it and the car stated. New switch and good to go. That was easy though, I could hear the pump cutting in and out.

50sman · Joined: 03 Jun 2003 Posts: 10 Location: SWEDEN

I start to suspect that I have a lot of combined errors. It is not a joyful view looking at the wiring. The former owner seems to be a wire fetishist. For example! When I started to make an inventory of all cables I found a big (4 mm2) in back of the trunk with no isolation what so ever at the end so when I took the cable (for measuring) I touched the (car)body with flashes and sparkles as a result. The cable was "loaded" with full power directly from the battery. It seemed like it was the cable to a former amplifier. So this is the case for the whole car. Home made wiring allower the place and in 95% of the cases I havent got a clue whats they are for (so far).
So I suspect that this might have some influence, or not!
To rule out the hot start problem I made wiring as told here at the forum and it seems that I got a little further. Now the car makes attemts to ignite and eventualy it does (3-4 tries). This compared to that nothing happend before.
It sounds however like the car is "missing" something. When it starts it takes 10-15 sek before it is up and running normally.

I will check the fuel pump, pressure, ignition switch to see if I can get even further down my road to a "happy" car.

By the way! What do you recomend regarding the wiring.? My idea is to "stripe" the car down cable by cable until it has only the vital cable left. Or do you have some other better ideas.
_________________
"Please, please - brake "

1998 BMW 540iAT - "The Jap Killer"
1980 924 - "For making my neighbours ...."
1998 MB E420 - "For lazy days"

miguelefe · Posted: Tue Jul 01, 2003 8:44 am Post subject: HOT START PROBLEM

For me, you are suffering the classic hot start problem.
The grounding of the cold start valve with a button is of help. I have done it, but you must press the button while cranking the engine, because if you stop cranking, the cold start valve will stop supplying fuel.
Have luck with your repairs.