i have a 95 z28 with 96,000 miles on it and for the last couple of days after driving for like 5 min. at 40mph it acts likesits out of gas it will stop if i bring the rpms up over 2000 and runs good again. thanks

 

test the fuel pressure, and also look and see if you cat is clogged up

 

When is the last time the fuel filter was changed?

 

No way of knowing if you have a fuel issue until you hook up a fuel pressure gauge to the Schrader valve.

 

This does not sound like the fuel filter. I would put my money on the CAT being clogged up or the fuel pump on its way out. Could you clarify what you mean by "it sounds like its running out of gas"? Does it sound like the engine is breaking up, or just act like it has no power?
If its your cat you will notice it getting worse and worse, your manifolds will get red hot too if you drive it. Keep your trips short until you figure out what is going on...

 

Sounds similiar to mine before it would die completely.. Try Cleaning the IAC motor under the throttle body!!!

 

Sounds like fuel, cat or a very dirty air filter. All easy to check. I had a mechanic drill a hole in the pipe right before the cat and insert a test probe so all 3 can easily be checked.

 

Nah, thats the opti most likely, if the fuel pump goes bad it just goes out with no symptoms. If equiped with a fuel regulator you can check that but I doubt it. Most likely its the opti crapping out @ high rpms and dying. Happened to me just today so I will be replacing mine. You can test fuel by disconnecting fuel lines and turning the key on.

 

have you tried to pull codes from the ecm? do you have access to a cable/laptop/software so you can connect up and do a data log?

 

no ses light or anything no cats either. fuel filter changed 1500 miles ago. only does it at that speed. it starts to bogg down until i bring the rpms above 2000 rpm i dont think its the opti because if it was wouldnt it do it at higher rpms too. i will have to check fuel pressure this weekend thanks

 

sounds to me like it be loading up. but checking your fp is still a good idea. if you can hang it out the cowl and see what it does whie driving.

i do have a question thouhg, does it bog if you just idle the car at 1800, not in gear? or how about in gear, brake on, bring rpms up. does it load up then....

when it does rev up do you get black smoke or anything out the pipes?

 

no smoke. it doesnt do it if i stop at a stop light and bring the rpms up.if i put it in neutral it will also do it until i bring the rpms up too it doesnt do it all the time just after the first 5 min it only lasts for about 3 min. thanks

 

maybe the injectors are dirty, i think its a symptom of clogged injectors when its rough in low rpms but not high. my mothers 87 crown vic did pretty much the same thing and i seafoamed it a few times now its alot smoother. try that

 

will do thanks for the help