Upgrade Posted March 30, 2003 Report Share Posted March 30, 2003 Heres the deal: 1995 3.4 DOHC Lumina LS Exhaust stinks like unburned fuel. Car is hard to start (have to flutter the gas pedal to get it going). Idle is rough and high (1100 RPM's) once it is running. Timing is right on. Gas mileage sucks. New plugs and wires. All the plugs and wires are connected and firing. Car will drive but it is shakey and idling high. The other day I was driving it and it started running like crap so I shut it off for a minute then restarted it and it ran fine except for the service engine soon light. Had to drive it a bit further and after a few miles it did it again and after shutting it down and starting it, it ran fine. I tried getting codes from it by jumping across the two contacts under the dash but the light never came on. Can anyone offer any suggestions? I have Monday and Tuesday to get it fixed. Quote Link to comment Share on other sites More sharing options...
JS91Z34 Posted March 30, 2003 Report Share Posted March 30, 2003 probable causes stuck injector/injectors, Bad fuel pressure regulator, MAP sensor, TPS, IAC motor, Low manifold vacuum, Mass air flow sensor. Try one of those and see what happens. Quote Link to comment Share on other sites More sharing options...
96montyZ34 Posted March 30, 2003 Report Share Posted March 30, 2003 possible EGR valve problem. Quote Link to comment Share on other sites More sharing options...
JS91Z34 Posted March 31, 2003 Report Share Posted March 31, 2003 possibly :? Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted March 31, 2003 Report Share Posted March 31, 2003 you cant jump the connectors on a '95....wont work. You gotta go to a dealer and let them check them. yeah it sounds like a MAP or even crank position sensor going out Robby Quote Link to comment Share on other sites More sharing options...
nriesen Posted March 31, 2003 Report Share Posted March 31, 2003 my car does the same thing, i dumped a bottle of injector cleaner in it with 93 octane, it ran fine. Now, next tank is 93 octane, and no injector cleaner...runs a lil rough again....weird. I had codes 35 and 43, but they havent been back since i cleared em about 2 weeks ago. Quote Link to comment Share on other sites More sharing options...
95GTP Posted May 6, 2003 Report Share Posted May 6, 2003 I have the same problem now. I have no idea where to start. It was running fine then started to chug/rough idle with real rich fuel smell. No visable leaks, all vacuum hoses seem to be connected. WTF?? Quote Link to comment Share on other sites More sharing options...
JS91Z34 Posted May 9, 2003 Report Share Posted May 9, 2003 Mine was an O2 sensor problem. I replaced every sensor in the car. Car runs good again. You could also try checking/changing plugs and wires. Just a thought! Quote Link to comment Share on other sites More sharing options...
CPSMonteZ34 Posted May 10, 2003 Report Share Posted May 10, 2003 Don't worry about the MAP, they stopped with the 94. 95 went to MAF with IAC and EGR being the most suspect in situations like yours. Since the computer is throwing a code, it's likely sensor trouble. Unless someone you know has a personal electronic computer scanner, any shop with a diagnostic scan tool will be the only place you can go. That's the safe way to go before you bother replacing sensors like Russian Roulette hoping to find the right one. Quote Link to comment Share on other sites More sharing options...
95GTP Posted May 10, 2003 Report Share Posted May 10, 2003 upgrade. check out this link, ita about my problem and what some of the ideas are http://www.efi-street.com/phpbb2/viewtopic.php?t=8649 Im going to change the fuel pressure regulator and intake gaskets again also I have never found anything weird about the 3.4L motor symptoms unless its running without any problems, now thats weird! ==95GTP Quote Link to comment Share on other sites More sharing options...
Slade901 Posted May 12, 2003 Report Share Posted May 12, 2003 All I can say is that you may have a failing cat. It barely allows your exhaust to pass through the cat chambers. The cat is suppose to burn those unburned gas but failing cat will cause this problem on your exhaust. Bad cat is usually a common problem and mostly mis-diagnosed ALL the time. Disconnect your O2 sensor and start the car and note the IDLE and car's performance before removing the O2 sensor and after removing the O2 sensor. Quote Link to comment Share on other sites More sharing options...
95GTP Posted May 13, 2003 Report Share Posted May 13, 2003 here is the deal. i was just about to send out my injectors for a rebuild when i decided to try and blow through it. Guess what? air went through the bad one. its stuck open! Looking for a deal on an injector now, looks to be about $80 for one. I still have to replace the cat since I know it crapped out. Time to get out the sawzall!!!!! ==95GTP Quote Link to comment Share on other sites More sharing options...
JS91Z34 Posted May 13, 2003 Report Share Posted May 13, 2003 80 bucks for an injector is worth it if its the new design! Quote Link to comment Share on other sites More sharing options...
95GTP Posted May 14, 2003 Report Share Posted May 14, 2003 What new design? Im looking into remanufactured ones for $47. I dont know if its wise to get one new design injector and have 5 old ones. Wont there be a major imbalance on fuel flow? Wont one cylinder get more fuel and run hotter that the other ones? If I could afford it I would replace all of them at the same time, Right now I'm freekin broke thanks to the 3.4l money monster. ==95GTP Quote Link to comment Share on other sites More sharing options...
JS91Z34 Posted May 14, 2003 Report Share Posted May 14, 2003 I'll be honest with you. The new design I'm speaking of is injector durability. Yours being a 95 might already have them. The older ones like what was in my 91 were junk. There was something about the design. I'm still researching different components of these cars. Finding out whats a bad design and whats not. Your not the only one the has an injector problem. Realistically speaking the motor is not at fault. The electronic component is. The 3.4L(LQ1) is not a bad motor. These motors are so opinionated by other people its sickening. I'm pushing almost 50K(in 1 years time) on mine, and the only time I was underneath the hood of my car was when the power steering line broke.It wasn't the motors fault. I'm getting ready for 2000 mile trip tomorrow in my Z34. I have complete confidence that this motor will get me to where i'm going and back. If you got an Injector that was dumping more fuel into one cylinder, the computer will see that and try to compensate for it. That one cylinder will run cooler than the others. If it were an extreme rich condition in that one cylinder, The computer is going to lean out all the cylinders to get the proper air/fuel ratio required. The new design is just a flaw that was fixed with the older ones to prevent premature fouling or shorting. There still the same injector, just made better with different materials. Quote Link to comment Share on other sites More sharing options...
95GTP Posted May 14, 2003 Report Share Posted May 14, 2003 I just sent all my injectors in for clean, test and recondition. I have a 50/50 chanc the stuck injector might free up, if not they will get me another one, all balanced with the same spray pattern and flow rate. I see what your saying. ==95GTP Quote Link to comment Share on other sites More sharing options...
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