Dtc Code P0300 When Cold

[chrisbmo2000]

Ok so here is the run down..........1997 Suburban 2WD 5.7L R engine code 206900 miles

So this morning I went out to start the "burban"(another abreviation to add to the list?) and let it run for about 5 min before jumping in and taking off.....(mind you the engine IS still cold) so the engine raises a fuss untill it warms up then it runs like a charm......Temp 24 Degress with light snow. A week ago it threw a P0337, P0339, P0430 but these have not shown back up and the engine was plenty warm when it threw these last 3 codes. Any Ideas???

[superjim]

If I am not mistaken...

P0300 indicates that the computer detected a MISFIRE on at least one cylinder.

[chrisbmo2000]

If I am not mistaken...

P0300 indicates that the computer detected a MISFIRE on at least one cylinder.

 

Yep but the question is.....which one the P0300 is a generic code and not cylinder specific also bear in mind this ONLY happens when its is cold

[superjim]

I would be looking at the plug wires first. I had one a few years ago that would miss a little bit when it was cold or when it was real damp. it would then be ok when it warmed up.

 

Check the fuel pressure regulator. Pull the vacuum hose on it and see if it leaks.

Smell the end of the vacuum hose for fuel smell.

If it is bad... it can cause low pressure and misfires.

 

A bad fuel pressure regulator would indirectly also cause the p0430 code... which is a catalytic converter code. It is not operating up to specs.