My '94 Blazer started running like crap just recently. It has no power and drives real rough. When I get to about 2800 RPM it fluctuates real bad then shifts into 3rd and then drops down again to 2nd. I have to keep the pedal to the floor to get enough power for it to climb even a slight grade. It had been driving ok for the past year though it seemed just a little underpowered, but over the last couple of months the performance and power just took a dive. I took it to Pep Boys for the Diagnostic check and they assured me it was the intake manifold gaskets. They also said my Cat was shot. I got the Cat replaced at a local muffler shop and worked on the manifold gaskets myself with a friend. Got the repair manual and researched it a ton! I was aware of all the pitfalls. Got it put back together with all the plug wires and vacuum lines hooked up correctly. Changed the plugs, wires, distributor cap, rotor cap, fuel filter, cleaned and sprayed (gumout) on all the TBI parts. Flushed the radiator, changed the water everything. Fired it back up (it started! yay) and took it for a drive. STILL RUNS LIKE CRAP!! Runs exactly like it did before. Actually at idle, purrs like a kitten. Runs and sounds great. Not like if the timing was off or the gasket was done wrong. I took it back to Pep Boys and all they say is that since they didn't do the work it's not their problem. But it seems for all the world like they got the diagnosis wrong. Does anyone have any ideas? I'd really appreciate it.
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Help!!
- Thread starter drusky2k5
- Start date
4xcrazy
3/4 ton status
check fuel pressure, you're decsribing some similar traits i had when the pressure dropped, idles fine, no get up n go
4xcrazy
3/4 ton status
dissconnect the fuel line going to the TBI unit, do it at night for best reading, use a lighter to see how much fuel is coming out when you try to start it... 
seriously, there is a gauge kit available, i believe though the fuel line must be removed and the adapter inserted in it's place, like in-line going to the TBI unit.
redneck way is look carefully at the sprat pattern when you hit the throttle, you MIGHT be able so see an ugly spray pattern when you rev it.
I did this with mine when i was having issues, at idle, the spray pattern looked "ok" so that might throw ya off alittle, but after a fuel pump replacement, there was a huge difference.
personally, i believe that if a fuel injected vehicle has more than 110,000 miles, more than likely there is a fuel pump issue.
seriously, there is a gauge kit available, i believe though the fuel line must be removed and the adapter inserted in it's place, like in-line going to the TBI unit.
redneck way is look carefully at the sprat pattern when you hit the throttle, you MIGHT be able so see an ugly spray pattern when you rev it.
I did this with mine when i was having issues, at idle, the spray pattern looked "ok" so that might throw ya off alittle, but after a fuel pump replacement, there was a huge difference.
personally, i believe that if a fuel injected vehicle has more than 110,000 miles, more than likely there is a fuel pump issue.
lectric80
3/4 ton status
Get a fuel pressure gauge from Autozone or another parts store that rents them. You can also take it to most local shops and have them check the pressure. Could be a bad regulator, or a fuel pump that is wearing out.
Usually there is a pressure tap that looks like a valve stem that you can use the read the pressure of the incoming fuel.
Usually there is a pressure tap that looks like a valve stem that you can use the read the pressure of the incoming fuel.
