dieing

I have a 89 5.7 1/2 ton I bought new. It now has 300125k on it. when I am in a parking lot are red light it starts to run rough if you try a give it gas it dies. and then when you crank on it its all most like a poping though the TBI when you sit and take the breather lid off after a few more cranks then will run. then going down the road it feels like a surge.

I checked the base gasket/ fuel filter/ fuel pressure/wires/plugs/dist-cap
coil new newECT/MAP

Help

Do you have a catalyst convertor on it. Have you checked to see if you have decent exhaust flowing out the tailpipes. Sounds like you could have a restriction, engine cant breath. Take the exhaust off at the y-pipe and start her up, if you notice a big difference....thats probably the problem. Just try not to "Tach" it up too much (hard to resist), especially if it's really cold out, dont want to suck cold air up the exhaust- on a hot engine.

can you loosen it at the converter? if so thats better than at the manifolds, (bad O2 signal)

Sorry, bad description....thats where I was talking. Undo one connection is far better. Thanks.

even though I had the fuel pump checked out, a mechanic thinks I need a new one. what do you guys think?

I have the same type of problem, does anyone know what is causing it????

with that much milage it could be the timing chain has slack in it causing timing to be off. just something else to think about

I found out it was a Bad EGR

Just some food for thought, a problem may still exist. I cant say I've heard of a EGR valve act in those extremes, anybody else?. If it helped, I would think that was part of it, but not all of it. Good luck

Just for good measure, change the 02 sensor, i did it in my 275K blazer and it did a world of difference.