Fuel pump voltage

[gmyoyo]

I am trying to trace down a problem with my 95 s10 blazer. It shutters/jerks while accelarating and at cruise speeds.

The other day while trying to diag the problem I ended up stranded at the gas station. Just filled it up and it wouldn't start. Turned over fine but no start.

I know how to listen and even test for fuel pump so I ran those test and wasn't getting any sound. So, I tow it home, pull the pump, take it to replace and the guy hooks it to a battery and it fires... So, he replaces it with a new one anyway and sends me on my way.

I tested the voltage at the relay in the glove box and I'm getting 11.4x or close. I have not tested with the relay in place as I'm not sure how, do I go under the dash, is there some connector there that will be obvious?

I did test at the three pronge connector at the tank and I'm only getting about half of that. Say 6.3 or such.

If I hook the overide to the battery (small red wire under hood for fuel pump testing) I get the full 11.4x at the three pronge connector.

The new pump fires everytime now and the vehicle starts. But as I said I am still getting the stuttering/jerking feel when cruising or accel.

Am I looking at this right. Shouldn't I get a full voltage load via the Relay to the three pronge connection as I did with the override wire?

Do I just randomly test the voltage along the wire harness, and how, since it's all wrapped and insulated and such.

[gmyoyo]

Anyone know what the voltage reading at the connector on the gas tank should be?

[Cailen]

Have you checked your fuel pressure at the shrader valve yet? Have you checked for a leaking fuel pressure regulator / nut kit? If not, pull your IMTV and have a look inside the intake for puddles of fuel / washing. It *should* be dirt black and carbony in there.