Lately when driving my 95 Z28, it will run fine for the first 5-10 mins, then randomly it will feel exactly like it's running out of gas if you try to give it a little bit more throttle it will continue to die out.

If I hammer it down a bit it will kick back in and come back to life, then a min or so later do the same thing again. Then it will run 5-10mins just fine again before starting the whole scenario again.

Does it sound like a fuel pump?

 

fuel pressure is certainly the first thing to rule out. After that try disconnecting an O2 and see if it goes away.

 

Could be just a fuel filter as well.

Hal

 

Mine does the same thing, what does disconecting the O2 sensor tell you??

I have no Cats but the O2s are plugged into the Long tubes were they should be. Dont they read things as being wrong if you dont have cats??

 

^ not the foward o2's. Check the connector on the knock sensor. I had a similar problem
and this was the cause.

 

missfire?

 

'95 doesn't have a post-cat O2 Sensor.

It could also be loading up on fuel. Run a fuel pressure test. If it bleeds down quickly, then let us know.

One reason for a bleed down could be a leaking injector. You can pull you injector rail... 4 screws. Then place a towel under the injectors and have a buddy crank it over for a few seconds and stop. The injectors should stop... any drips indicate leakage.

If you have an injector sticking open it could be loading up on fuel and cause a driveability concern. When you step on the throttle, you are allowing more air into the system and the unburnt fuel is blown out.

Just a thought. I would recommend a fuel pressure test.

 

Will get me a gauge this weekend

 

Any DTC's?

 

Dtc?

If that's Diagnostic Trouble Codes, yeah it has a few actually, Left O2 Sensor, Fan Relay(known problem...), some other minor things.

I'm in the long process of fixing up a nice car that was rednecked back together after an engine swap.

 

Please post your results on the fuel pressure test. I just started having this problem too. I changed the fuel filter but the problem continues.

Is there a way to tell if the fuel pump is about to fail? (other then getting stuck on the side of the road)

 

Will not be doing it until tomorrow am sorry

 

No problem. I just learned the place I have been getting gas has been causing a lot of people to complain about how their cars are running.

My problem only happens after I have been driving for about 60 minutes. Is yours doing the same? Have you tried fuel system cleaner?

 

You can check the injectors without cranking the engine. Just turn the ignition to on..the FP will pressurize the system and leaky injectors will be obvious. You really shouldn't ever crank the engine with the fuel rail off...it'll create an explosive atmosphere in an area where you just don't need it....

 

bw_hunter > I do agree that a fuel pressure test can be determined with the rail on. Also, you can determine if an injector is stuck open by watching the fuel pressure drop.

You are also correct that when dealing with an injector rail out of the engine that there are some concerns with volitility. If clean towels are placed under the injectors when cranking over, you will see "soft" circles on the towels. If one or more of the injectors spray streams on the towels in "tight" circles, then those are potentially clogged. No, it isn't as specific as a fuel test station with a glass beaker, but it works for a general pattern if you compare the spray circles... should all be the same. Always use extreme caution when working with fuel.