Hello, at anytime have you had the check engine light come on? if so do you know what codes were set?
it runs rough for a second or two only then runs 100%. usually it will try to start or barely start for a second and then die. sometimes have to cycle fuel pump 5-6 times before trying to turn over the engine in order to start but when it does catch it just sputters for a second and then purrs. does this model have a regulator? or could a weak fuel pump or even the sock in the tank cause this?
This engine uses a special design of "fuel injector assy". We refer to it as the "spider" injector" See below. it is all one piece and the injectors are actually called poppets. mounted on this "spider" is a fuel pressure regulator. You are describing a loss of fuel pressure after sitting. This is caused normally by one of two things. the regulator allowing fuel back to tank OR the "spider " assy where as a poppet is sticking open slighly. the fact you get brief rough run leads me to a bad poppet or "injector assy". these had known problems from injectors (poppets) not seating correctly due to debri caught at the tip of one or more. This will allow fuel to drip into cylinder while sitting, cause brief rough run upon startup and then clear out once the fuel burns off. Usually pretty quick. If you had a bad regulator, fuel would loop back to tank and keep doing that and making starting almost impossible and if it runs, it would barely run at all. I am leaning towards the "spider injector' assy being bad. very common. So much there was a recall for the ones in California for poppets sticking. Now... you have 1 of 2 options. many times you can have a shop do a full fuel injection flush and soemtimes this will get the tips of the poppets clean and you will be just fine. This does not always work. In this case, the fuelmeter assy "spider" will need to be replaced. not too bad of a job but the upper manifold must come off to replace it. A fuel injection flush by shop generally about $75 on the average. This problem will not get better but worse over time. Fuel additives just do not work.