Well the battle continues with my 95...

So I just started a job with the Georgia Dome and live North of Atlanta now and so I commute in the Jimmy..

Well heres the deal- I have to change the plugs every few months (they get the greyish chalky look on them)

And also the bigger issue for the time being is that like on the interstate to work the truck is under powered and starts to "misfire" is the best way I know to describe it above 2-2500 rpm. Even if your out of surface streets and you try to get up and haul A$$ it will do the same misfire.

It has a new CPI injection unit and fuel pump within the last few months.

Almost every sensor on the engine was replaced within the last year (rebuilt engine bored 30over) with the exception of the crank sensor.

Truck has OBDII capabilitys but no check engine lights or anything. My gas milage also pretty much sucks. Please help!! Thanks guys

 

Did you replace the fuel filter when you did the pump? With no codes, it's hard to tell. Also, what brand fuel pump? Lot's of horror stories around here with non-Delco or Delphi pumps. Also, a lot of people say to only use Delco plugs, but I'm not sure it that would cause as dramatic a problem as you're having.

It might be ignition, but that would more than likely throw a code.

 

The pump is a delco pump. The filter is less than a year old so I didnt feel that was necessary to change. And I also did an after fuel pressure test and the pressure is fine so Im 99% sure it isnt fuel related. Also delco plugs. But non delco wires cap and rotor but all are new within the last 4 or so months. Im kinda curious if it could be the coil going bad or if the computer isnt adjusting the timing correctly under a load.

 

Greetings

I also have a '95 two door 2 wheel drive , but mine is an earlier model than Yours as You say it has OBD2 - - I have OBD1.? ... (computer is under glove box and distributor cap has vertical posts on it ). You might check the EGR valve as it may be partially clogged or not closing fully due to carbon build-up. Mine did that until I replaced the fuel pump . I would replace the in-line fuel filter too if it were me , a year old filter with a new pump

 

EGR is a good place to look. If you do end up removing it, make sure you get the gasket with the screen in it. If not, it won't be long before another piece of carbon sticks in it and holds it open again.

 

Yeah Ill probably pull it off and clean it my next day off. I dont know why Ive never even thought of the EGR Valve but oh well thats what the forum is for. I need to figure out the problem because I am now trying to sell the Jimmy because I commute quite a ways now so fuel cost/cosumption is killing my wallet. Hate to get rid of the thing after all the money Ive sunk in it but it will make someone else a good truck.