I've got an 86 951 with about 137K miles on it that I just bought a few months ago. When I first got the car, it would take about 10 seconds or so of cranking the engine before it would start up. Then all of the sudden, it magically fixed itself and would crank right up. Now that I've put about 2k miles on it, the car desided that it doesn't want to start up without some effort.

I'll crank on it for about 10 seconds or so (closer to 15 seconds if it's freezing cold in the middle of the night) before it starts up. Once it starts, it idles pretty rough for another 5-10 seconds and wants to die. Then, it just purrs to life and runs okay. (The car will still run a little rough until the temperature warms up a little bit, but I'm assuming this is normal.) The car used to just crank right up on the first try, so I know it can do it... any ideas?

*edit*

I've searched through some older posts and my first idea is to replace the fuel filter and the "fuel pump check valve". Anyone have any other suggestions?

 

One possibility is the throttle postion switch- mine was doing similar things, and they were cleared up when I changed mine. It could have been coincidence, as I only changed the TPS b/c of boost problems (erratic boost b/t 1.2 and 1.6 bar Total boost @ WOT)- anyway, after changing it, the little idle problems mysteriously dissapeared...

 

Also...check the injectors. If youhave a "leaker" the fuel system has to pressure up again. Try turning the key to the "on" position without cranking. Leave it there for 10 to 15 seconds and then crank it. See what happens

Bob S.

 

If you DO have a leaking injector, you may also smell gasoline odor on the dipstick or the oil after you drain it. If you do, get it fixed IMMEDIATELY. Gasoline mixed with your oil will lower it's lubricity and viscoscity dramatically, so much so that you'll end up with rod/main/turbocharger bearing failures in no time.

A failing fuel pump could also be the culprit. It's supposed to "hold" fuel pressure when it's off, but sometimes they allow fuel pressure to leak-back into the tank, necessitating a re-pressurization when you start the car.

A fuel-pressure test guage would help you diagnose your problem, as would checking your oil for gas.

Greg

 

Just turning the ign on will do nothing, the Pump is not powered unless the engine is running or cranking, bridge the fuel pump relay to comfirm a leak down problem, if this is the cause it can only be either the check valve or a leaky injector.

 

how can you test to see which injector is havine leakdown ? i have the rail pulled, and the injectors are sitting in cups to see which gets the most gas in it, but i didnt take into consideration how much will evaporate if its a slow leak down. Any idea's on how to test them ? i just had them rebuilt, but my mechanic said there is leakdown.

its becomming a royal pain in the ***

thanks,
Jeff aka Lamah

 

Cable tye small plastic bags around the injectors, put some paper in the bags, it will discolour even if the bags leak dry.