I am having trouble with a 94 full size blazer. I want to buy it off a friend but for some reason, the engine dies about 5 seconds after you start it. It barely stumbles before just shutting off. if I rev the engine to 3K RPMs, the engine will run a few more seconds but then it stumbles and the RPMs just drop until she dies. It is a 350TBI engine w/ 140K miles on her. my buddy started having problem withit last week when it just dies while he was driving. He started it back up anddrove it home. he said it did stumble a little bit though as he drove it home.
All the gauges look good before it dies and there is no SES light on. What could be causing this to happen. I want to pick this thing up for the cheap money he is asking but I need it to run long enough to get it to my house.

 

I believe the fullsize trucks have the same passlock as the s-series. If that is the case, then this sounds like a passlock issue where the PCM is shutting the engine down because it isn't getting the proper reading from the key. Does the key have a little chip in it?

 

I will have to check on that and see what I come up with. If it is not that then I am going to have to assume it is not getting fuel and check the pressure. Any idea on where the test port is on this truck?

 

If it's a TBI motor, then there is no test port, you will have to put an inline adapter in for your fuel pressure gauge.

 

I now have the truck here and now it will not even start anymore. I do not hear the fuel pump priming when I turn the key forward. Now, I want to change out the pump but need to know if there is an access panel under the rug inside the truck or not. if not then I guess I gotta just drop the tank out from below right? Theres nothing special that needs to be done at all?

 

No access panel, you have to drop the tank.

 

well I just removed the two straps and the tank will NOT drop. it is either held in there by something else or its really really jambed up in there somehow. I will keep trying.

 

Be careful as there are lines and the filler neck that need to be disconnected before you can drop it to the floor.

 

the tank is now out. what a PITA. it was stuck up in there from the padding that is on the tank. Yes I was aware of the lines and plug. The connector for the plug has a ground wire that is bolted to the frame for those of you reading this thread looking for help. Also, the feed and return lines where so bad that the minute I started turning them, there was a fine spray of fuel spraying out of a tiny hole right at the 90 degree turn into the pump. So, it looks like I will be needing a new sending unitas well as a pump. All well

 

The same thing happened on my dad's '94 K2500 pickup when we changed out the pump and subsequently the sending unit.