My 92 RS has never been a preformer to say that least. At least not in comparison to the other thirdgen I own. An 88 IROC pushing over 320hp to the rear wheels. However with a Heritage Package and a covertible roof & suspension tuned to hold her to the ground she is a lot of fun to drive Anyways to date I have changed the EGR, EGR Vaccum Selenoid, Flow checked the injectors, swapped the air cleaner to the L69 sytle dual inlet system, changed the fuel filter, giving her SLP 1 3/4" headers matted to the SLP Y-Pipe, IROC intermediate pipe and a flowmaster muffler, Borg Warner Select Wires, Platinum Plugs, New Cap & Rotor. Why am I going through that list well because here are the sympthoms that I need some dire help diagnosing:
At best maybe 160 Miles to a tank of 91 fuel!
Strong odor of fuel while driving
Surging problem at idle and in gear
Major loss of power as of late, very sluggish through all the gears especially off the line!

Her 5.0 is original as far as I know along with the 135K miles, WCT5 has never been overhauled to my knowledge. I just purchased her back in OCT. I would really appreciate any and all help that could help me figure out what is wrong or what I should try to change next. TIA

 

sounds like possibly the fuel pump. when my pump was going bad i got horrible gas milage. used about a half tank a day. it would surge real bad and usually die when put into gear but once it got moving and warmed up alittle it would idle fine and everything until it cooled down again. might try pressure testing the fuel.

 

Check or change the o2 sensor. How does it run when the engine is cold. If it seems normal untill it warms up check the o2. If it acts weird all the time check for a vacuum leak. A vacuum leak will make the ecm think the engine is under a load and add fuel. Could also have a bad map sensor as well.

Steve

 

i second checking the fuel pump. test to see how much pressure there is at different rpms and stuff. when mine was going out i got bad gas mileage and had problems starting it

 

I second the O2 sensor. Fuel pump can be checked by monitoring the fuel pressure- just to rule the possibility out.

 

Thanks for some ideas. The motor is not burning oil (as I keep checking) no smoke at start up. I found some of the problems I mentioned last night appearently #8 plug wire was burnt (I just replaced #4 & #6 like two nights ago) also the exhaust donut is shot and the tubing on the side of the cat was off Anyways the fuel issue has been the same since I have had the car. I guess I will have to try a chip, as I am not sure what else it might be? Oh yeah do you guys think a bad coil & or distributor might be making my problems worse? The reason I ask is because the computer will keep the RPMs pretty high as in over 1700 at idle or in gear! Then as it trys to bring them down gentely on occassion the motor will sputter and die. And then I have a helluva time getting the beast to start up again, makes it seem like the starter is bad. But since the volts are good, even with all the accessories on headlights and heater dead in the middle of the road I still had like 12 volts. I am wondering if either the coil or distributor are giving me bad spark which is what is causing some of my problems? TIA

Also I should have mentioned I changed the O2 Sensor when the headers & Y-Pipe were done which was about a month ago. It sounds like I should take a look at the fuel pump then, though what does the pump do with the fuel if its bad? Meaning where in the hell does the fuel go if the motor isn't burning it up?

 

it goes straight out the exhaust...poor gas never gets the chance to move the car.