Cadillac Seville / Cadillac Eldorado Forum Discussion, 93 Seville 4.9 Running rough in Past Cadillac Vehicle Discussion; First off I must say this forum is top notch. I have gathered mounds of information here since picking up ...
First off I must say this forum is top notch. I have gathered mounds of information here since picking up my Caddy a little while back. Ok, I picked up this Caddy a few months ago as a winter beater while my MB rests in the garage. Well I kinda fell in love with this car. The problem is it is running a little rough and when I step on the gas it hesitates a little then it will just kick in go!
I replaced the entire exhaust when I bought the car. Yesterday I replaced plugs/wires/cap/rotor/coil(All AC DELCO), it runs a little better now but not like when I got it. It is not throwing any codes except for suspension. I also changed the oil/filter and air filter as well. Could it possibly be the EGR , Fuel filter or vacuum leak somewhere? Those are the only things I havent tackled as of yet. Im kinda stumped right now so any help would be greatly appreciated.
Start w/vacuum leak diagnostic, listen for sucking, check all connectors, hoses.
Check your plug gaps.
Check for a leaking Fuel Pressure Regulator.
Check the impedence across each injector (sometimes when they go their internal state changes, more common on low impedence injectors which the 4.9 does not use, but it's worth a shot) Just get a multimeter, cheapo will work.
I will start with the vacuum system tonight and progress from there. I know the plug gaps are good just did those yesterday. I will post up the remedy to my woes once I figure it out so others can utilize the info.
I found one small leak at a connector in the vac system. Timing was ok, The egr tubes in the TB had a little carbon but not blocking the tubes. Still running like crap and actually is getting worse. I did notice a ticking coming from the distributor cap, never heard on the old one. Is it possible to get a bad cap or rotor? I have never come across a bad new one. Aggghhh.
Well after alot of searching in the forums I stumbled across a post about shutting off individual injectors through the PCM override. Low and behold my #2
injector was shot. I replaced it and now she purrs like a kitten. I also replaced the fuel filter which was heavily clogged(you barely blow thru it), which also helped out a bit as well. Thanks to those who responded to my post.