And out goes your o2 sensors lol.

 

Stay away from oil system leak stoppers!!! They expand the rubber seals and usually stop the leaks until you change the oil again. Additionally they swell all seals not just the one that is leaking. You state that the oil pan leak seems to have stopped. Just for good measure you might want to make sure the pan bolts are tight. The oil pan gasket is a set thickness and can't be over tightened. Don't go nuts but make sure they are tight. You would be amazed at how often these bolts work themselves loose. Yes, oil pan gasket replacement is a pain. You have not mentioned that your truck is smoking or using oil. High mileage oil is basically oil which is designed for high wear of piston rings and valve seals. I would imagine that it has a thickener (sticky component) much like the no smoke which is also available at auto parts stores but not advisable to use. 10w30 is fine for winter but 5w30 would be better if the truck doesn't start using it. Keep in mind that the thinner the oil is the better fuel mileage your vehicle will get. You just need to find the lightest oil you can use without the truck using oil. When engines use oil they tend to plug up the catalytic convertor and mess up oxygen sensors.

 

I had a 98 Blazer which did exactly the same thing when I first bought it. If you do not already have one get a fuel pressure test gauge and check the trucks fuel pressure (key on engine off). The place to hook the gauge up is just in front of the distributor and towards the drivers side. You should get 58 to 65 PSI of fuel pressure. If you do not, to rule it out, change the fuel filter which is located on the frame under the drivers seat. If the fuel pressure does not change and is still low the problem, which is super common in these trucks, is more than likely the fuel pump assembly. In tank! Bummer!! Not to worry, it really isn't that difficult to do or maybe I am saying that because I have done a few. Takes me less then an hour now. Just a good pointer. Before you do anything "carefully" remove the vent hose from the front top of the tank (at the tank not the steel line) because this will cause you to break the plastic nipple requiring that you buy a replacement fuel tank.

btw, Sea foam fuel system cleaner which was mentioned earlier in this thread is awesome.

 

70camaro, thanks for all the advice so far. With eevrything youve said in mind, im gonnna change it with what ive been using, mobil conventional superclean 5000. While Im changing it I will also check to make sure all the bolts are tight. Im hoping they are a little loose and thats causing me to sometimes use a little bit of oil. As for the fuel filter, that was just replaced, along with the fuel pump, which I went with the oem ACDelco pump. So i dont think thats where the issue lies. Thanks for all the responces and ill keep you updated after i do the oil change

 

Have you acquired a fuel pressure gauge yet and found exactly what pressure the system has? I know that stores like Autozone and Oreilly's lend out tools for free. Not sure if they have fuel pressure gauges to lend out but it doesn't hurt to check instead of buying a tool you might use only once or twice. You just have to give them a deposit which you get back upon returning the tool. This is a must in troubleshooting such a problem. Otherwise you might be throwing money away by troubleshooting by installing new parts to find the problem. That gets expensive quick!

 

fuel pump was changed a few months ago and it still did the little hesitation thing right after it was done. When it was tested after the pump was done, it was at like 60 i believe

 

Never assume or guess fuel pressure when troubleshooting. It only ends up with you buying parts which don't need to be replaced making you chase the problem. New fuel filter, check fuel pressure, if low pressure still then pressure regulator. If pressure is within specs I would first start with the simplest procedure by running a quality / strong fuel system cleaner like Seafoam through the system to see if it cleans out the system and corrects the problem. Unlike other vehicles, to my knowledge, the Blazer does not have a place to pinch off the return line to the tank to test the pumps ability to pump max pressure without running the risk of damaging the plastic line. I would be afraid that the plastic line would crack. If all else has been verified to be good the only remaining part is either the fuel pressure regulator or plugged injectors. The regulator is part of the injection spider. I recommend changing the spider but it is more money. If money is tight then just swap out the regulator. Plugged injectors can cause the same issue and since you have the top of the intake manifold taken apart anyway I would just change injector spider. I hate doing work twice.

 

Yep - that spider is the biggest abortion ever created by GM.