help please, 98 gmc running crazy

[chevyndn]

ok. i have a 98 gmc with a 5.0 and a 4l60e. i was driving it thursday morning and it ran fine. later that day when i was going to work i noticed it started to miss when running. i made it close to my job and started to slow down and thats when things got worse. it would not idle right and if i didnt hold the engine up to at least 1000rpm the truck would die. i managed to make it home the next morning, and now i have a truck that does not run right sounds like it has a monster cam. i have tried the egr, the i.a.c, and the t.c.s. i also tried the old dizzy just to see if maybe i have a bad one even tho ive been driving it for a few months with the new one. i still need to write down what codes im pulling but i remember something about it saying it is ignition related. oh yeah it also is running very rich at an idle and some time i have to hold the gas pedal to the floor to start it. it has a new m.a.f sensor to. and all new 02 sensors, i think thats all ive done so far. any ideas??

[Boog]

Check the fuel pressure first. You are looking for around 60 - 64 psi.

[chevyndn]

ok, i will try that tomorrow when i wake up since i work second shift.

[chevyndn]

i pulled the codes and i have p0405, and p1345...and help with this?

[awbrown]

My 97 ran kind of weird like that when the intake gaskets went .. all I had to do was take the oil cap off and I knew what the problem was...

[chevyndn]

i dont have any water mixing, but i just smell like it is dumping raw gas into the engine and makeing it run to rich. if you can get the engine to a higher speed it dont sound as bad like it is not dumping as much gas but i havent been able to work on it this week since im trying to finish up my blazer for the winter.

[gregory5000]

Here is some good reading for you.

http://www.topix.com/forum/autos/che...C4SM20M2A0TULE