450SL won't start cold or hot

please help...I can't get my 450 to start properly..cold or hot....

[michael rybikowsky]

Jonny you have to narrow it down.I assume you have service books our CDs.First see If you have spark to the plugs.Second see if you are getting fuel where it needs to go.You can put a little fuel in the intake and see if it starts.You have to narrow down this question to get a solution.There are to many variables.Good luck Michael

[ericdee]

JJ,

Does it blow a lot of smoke out of the exhaust when it does start? The reason I ask is that the fuel injectors tend to leak after awhile. I had that same problem on my 83 SL, cold or hot it would sit there and crank and crank and crank. It turned out to be the fuel injectors. I replace the injectors and it fires up on the first crank and runs really smooooooooooth.

Had the same problem with my 82 380. Turned out the fuel pump would was not turning on. Traced it to what is called the kick down relay and its located behind the glove box once removed. If you have a second person available, have him crank the car and place your hand on the pump. you should be able to feel it working if it is turning on. You should also hear the pump energize as soon as you turn the key on for a second or two till the fuel system pressurizes.

[DZLPWR]

On a CIS system, 76 & later, you can leave the key in the on position and disconnect the saftey wire at the manifold. The pump should run continously. Even if your pump runs, the fuel pressure may be too low. You really need a fuel pressure gauge. My 76 pump ran with low pressure at about 215k. Cold starts were ok, warm starts were difficult. My 77, with unknown mileage, fuel pump failed and I rolled to a stop on the side of the road, totally SOL that time.