Here's the low down. My 2 dr s-10 blazer 4.3 non vortec started up every time, but it ran way too rich and when driving seemed like the engine was literally drowning and couldn't breath. So replaced the fuel pump which works fine but we go to start it and it won't turn over more than once or twice. Fuel pump is definitely getting gas to the injectors, but the injectors are barely dripping. Tried to clean them but not sure how to really get them apart and worried it might be the computer. Any ideas? Like I said started up every time before, just after we put the correct and working fuel pump in it wouldn't start.

 

Are you saying the motor won't crank? Like a dead battery?

 

No, it cranks, the engine just won't burn the fuel. We assume because the injectors aren't spraying right. At least thats what it looks like.

 

I don't know much abut a TBI system but I know on a CPI system you have to get all the air out of the system after you work on it, but turning it off and on a few times should do it..You really need to know how much pressure you have..Did you change your fuel filter? And just because the pump is new doesn't mean it's good. That's why you need to check the pressure..I ordered one not long ago and they gave me one for a TBI, looks exactly like the CPI but only put out about 20 pounds of pressure.

 

We did our best to get the air out and turned it off and on at least 50 times. The parts guy made sure it was the right one. We haven't been able to check the pressure, we just have the oem pump for the blazer with correct model and engine info, but now she won't start. We'll try to get the pressure checked tonight. I don't think its that though. The injection ports are definitely not doing there job right.

 

I know the TBi has a fuel pressure regualator in it. Thats the things that the fuel line connects to and goes up and over to the injectors. The injectors should spray in a nice circle pattern. Try to put strait gas into the TBi and see if it starts.

I am pretty sure the TBi needs 9 to 13 PSi to run properly, but I am not sure if there is a check valve on the 4.3L\

I would also check the spark plugs, gap, and make sure you are getting spark to them. The whole gas in the throttle body would kinda rule that out, like it runs or putters for a minute after you put some gas in it.

PS- Fuel pumps aren't always good (they can be a defect). I will never buy "unnecessary" parts again, always test for your problem. You can create a problem by buying a new part and it being faulty.

 

The fuel pump pumps fuel to the engine, whether its the correct pressure or not it is working. We poured fuel right into the throttle body while cranking it and it did start up and run off it for a few seconds. Still can't figure it out though.

 

Do you hear the fuel pump working then clicks when you turn on the ignition? Did you disconnect your battery cables before changing it? If you didn't you could have caused some harm to your electrical system. Check your fuse box.

 

We did disconnect the battery when we changed the pump. Fuel pump is running when we turn the key to on. What do you mean it clicks? The fuse box has no blown fuses but it does have two empty leads that you would think a fuse fits into labeled "IGN", but the plastic isn't cut out for a fuse to actually fit. That can't be it though, if there was no power running to the ignition would it even run when I crank it and manually pour fuel into the intake?

 

It clicks at the end after the pump has pumped some fuel and stops. It's like "mmmm(pumping fuel)mmmmmTK (stops)"
And no, it wouldn't crank if there was a missing fuse.
Maybe you could take off your fuel filter, put a bucket under both sides tubing (in & out), ask someone to open the ignition and see if fuel is pumped out (be careful as it could splash your eyes, so be ready to shout "STOP" :P )