When it is cold out, I can NOT start my car. If I warm the car up (pushing into the garage and warming it up over 40 degrees F. It will start.
However, it will only start if I first depress the gas pedal and then take my foot off the gas. It will ONLY start with the pedal NOT depressed. It really sounds like a fuel problem.
Once the car starts, I can give it gas and then it runs GREAT, idles (with only a slight knock)
I KNOW it is not the glow plugs (I have pulled them all out, connected them just like when they are in the engine and watched them all glow).
I recently replaced Both fuel filters (primary and secondary).
At one point on the secondary fuel filter, it did look like it may have been sucking air but I sealed that up (around the bolt that holds the secondary filter up). I discovered it when I filled the car up to the top with diesel with rear tires on jacks and saw diesel come out the bolt on secondary filter but that is not happening anymore.
The only thing I can guess is:
1) Fuel Injectors 2) The actual Injector. Question: how hard is it to check for compression? Also, someone said there is some vacuum hose to the injector that may be causing the problem, Can somone tell me what his is and if this could be the cause of the problem. 3) Valves need to be adjustedANY other thoughts out there or simple checks I can do?