924Board.org

[badenkb]

HI

I've looked through the tech section on cold starting but was also wondering if anyone had experienced similar problems to me ?

I have just replaced all fuel lines and fuel hoses , but have reused fuel pump and accumulator. Trouble is, it doesn;t start anymore.

I have fuel delivery to the mixture unit and returning to the tank, but nothing at the cold start valve (I have measured the current to it and removed it from the manifold to check for any spray).

Assuming if everything worked before and I have changed nothing else - I am getting the feeling of either a failed cold start valve( but the engine does not even attempt to catch) or the new fuel lines are of a slightly different bore, meaning pressure is down (and hence no cold start valve action and/or fuel pump was weak anyway)?

Anyone experienced anything similar ?


My new fuel lines came from Automec - a well known UK company and were OEM standard replacements.

Any help greatly appreciated!!!

Thanks

Ian
77 924 project

[larso]

prolly needs a mixture adjustment now that new stuff has been added, it should start w/o the CS valve after a few cranks.

[larso]

if you are in doubt about fuel pump though, do the quantity check. I think it's 750mLs of fuel, taken before the fuel filter after 30s of running the pump. You do this by jumpering the terminals at the relay board after popping the fuel pump relay out.
Refer to haynes for exact volume/time, i may be off by 1-200 percent.

[kaffine krazed]

You can try using carb cleaner to run the engine spray some into the throttle body then try and start the engine. If it starts on that then you know there is a problem with the fuel side. If it still doesn't start check for spark and compression.

[badenkb]

Hi

Thanks for the advice all - will try the fuel pump first to check displacement. If thats Ok - will try the cleaner to kick start it and then look to the mixture (hadn't though of that).

Will let you know how I progress...?

Ian

[badenkb]

Hi All,

Much to my embarrassment, the reason my 924 na would not start was not due to new components - but due to a huge air leak I had in one of the injection boots. Managed to seal it and it starts OK if a little rough. A previous posters comments ont he mixture not maybe being out, seems correct as there was quite a bit of backfiring and popping.

Ian

[Vince Ponz]

I went through the same thing when I got my 931. I changed and cleaned all the grounds and the car ran better. Also changed the fuel pump, filter and accummulator.

Now it runs as good as it should. The cost for the ground straps should be about 10 US.
4 of them

[larso]

Also the positive cable that goes to the starter is a good thing to replace if it looks green..on the 931 you have to leave the old one in since it goes with another harness, and throw in a new one. The 924 NA i can't remember, but if it looks green and has powder coming out of it, replace the positive cable too.