supreme_style21 Posted May 5, 2003 Report Share Posted May 5, 2003 '94 GP, 3100 engine. Idles fine. When driving, doesn't have the 'get up and go' that it used to.. kinda slugs along when you hit the gas and wanna go somewhere. I'm getting really stupidly bad gas milage.. like 15 mpg highway.. if even that. Transmission fluid/filter changed, new plugs, plug wires, fuel filter, ignition coil, fuel injectors (professionally) cleaned. What the heck could this be?! I was thinking oxygen sensor needs to be changed. Also, what happens when a fuel injector stops functioning? Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted May 5, 2003 Report Share Posted May 5, 2003 02 sensor sounds like a good place to start. If an injector stops working you would be on 5 cylinders. duh Robby Quote Link to comment Share on other sites More sharing options...
Whiskey River Posted May 5, 2003 Report Share Posted May 5, 2003 Yeah, try the O2 sensor first. If no codes are thrown it could still be a poisoned sensor. Also check the wire from the O2 sensor and make sure it isnt grounded on anything. Quote Link to comment Share on other sites More sharing options...
supreme_style21 Posted May 6, 2003 Author Report Share Posted May 6, 2003 02 sensor sounds like a good place to start. If an injector stops working you would be on 5 cylinders. duh Robby well ya.. but what does that feel like? Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted May 6, 2003 Report Share Posted May 6, 2003 sorry, I was in a mood then. It'll run very rough have like no power, the exhaust will smell of gas. It might die sometimes in traffic, idling in gear. Robby Quote Link to comment Share on other sites More sharing options...
NOHC_WBody Posted May 6, 2003 Report Share Posted May 6, 2003 It'll feel like a shuddering in the rev range as you accelerate, kinda like it will pull for a sec, and let off then pull again. Quote Link to comment Share on other sites More sharing options...
xxXRandyyXxx Posted May 7, 2003 Report Share Posted May 7, 2003 not to steal your thread but this goes to robby1870, you said it might stall in traffic, with my car, the first time you start it, she'll run awesome. But if you turn it right off and start it again, it will try and stall and run like shit. The RPM'2 will never be stable at idle or anything. Could this be the same problem? Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted May 7, 2003 Report Share Posted May 7, 2003 It might be. But, it sounds like it could be a MAP sensor going out. Or a vacuum leak Robby Quote Link to comment Share on other sites More sharing options...
badprix Posted May 7, 2003 Report Share Posted May 7, 2003 i had an oxy sensor go bad before....when you start your car go and look at your tailpipe if you see a lot of black smoke its most likely ur o2 sensor or better yet have someone give it a lot of gas and youll see the carbon come out and youll smell it becuase when an o2 sensor goes bad the enegine will run extremly rich. Quote Link to comment Share on other sites More sharing options...
GPRACER Posted May 7, 2003 Report Share Posted May 7, 2003 sounds like it could be an EGR valve sticking open or closed too, would definately cause a poor idle and sometimes a hard start condition, also fuel economy would go down the crapper. Quote Link to comment Share on other sites More sharing options...
JS91Z34 Posted May 9, 2003 Report Share Posted May 9, 2003 I replace the O2 sensor and the CTS on customers cars as a pair. The CTS will hinder gas mileage severly if its bad. The CTS is what tells the ECM how hot the car is running among other things. A bad CTS will not let the ECM go into closed loop operation. In other words, a bad CTS will not tell the ECM how hot the car is, therefore fooling the ECM into thinking it's still running cold and dumping more fuel into the motor in a attempt to get a temp reading to the ECM. If that helps at all? Quote Link to comment Share on other sites More sharing options...
supreme_style21 Posted May 10, 2003 Author Report Share Posted May 10, 2003 Any way that would lead to the car running hotter than usual? It runs around 220.. doesn't take too long to get that hot either. It never ran that hot until recently. Where/What is the CTS? and dare I ask how much that'll cost?? Quote Link to comment Share on other sites More sharing options...
Slade901 Posted May 10, 2003 Report Share Posted May 10, 2003 I would assume that the CTS = Coolant Temperature Sensor. Quote Link to comment Share on other sites More sharing options...
Slade901 Posted May 10, 2003 Report Share Posted May 10, 2003 I replace the O2 sensor and the CTS on customers cars as a pair. The CTS will hinder gas mileage severly if its bad. The CTS is what tells the ECM how hot the car is running among other things. A bad CTS will not let the ECM go into closed loop operation. In other words, a bad CTS will not tell the ECM how hot the car is, therefore fooling the ECM into thinking it's still running cold and dumping more fuel into the motor in a attempt to get a temp reading to the ECM. If that helps at all? That's some good advice. Here's also a link about other sensors. The O2 sensor is the last authority on trimming the fuel mixture. http://www.asashop.org/autoinc/jan97/techtotech.htm Quote Link to comment Share on other sites More sharing options...
supreme_style21 Posted May 10, 2003 Author Report Share Posted May 10, 2003 I would assume that the CTS = Coolant Temperature Sensor. Oh.. I tend to miss the obvious. Guess that explains the running hot. I replaced that bastard about a year ago. Quote Link to comment Share on other sites More sharing options...
firebirdbob Posted January 10, 2013 Report Share Posted January 10, 2013 not to steal your thread but this goes to robby1870, you said it might stall in traffic, with my car, the first time you start it, she'll run awesome. But if you turn it right off and start it again, it will try and stall and run like shit. The RPM'2 will never be stable at idle or anything. Could this be the same problem? I have a 1994 Firebird V6 and my car does almost the same thing. First trip of the day it runs great. After I park then restart it it runs pretty rough but not as rough as a full-on miss. I don't get a lot of black smoke or anything but I just changed my Plugs, SP Wires, All 3 Coil Packs, and even my Coil Module. The Plugs looked pretty sooty ie carbon fouled. A few years back my car had a over heating problem too. I had the CTS and Thermostat changed then but it still ran sort of hot in summer. My car isn't throwing any codes except for ABS inoperable light and the cruise also stopped working. I'd be grateful for any tips or suggestions on what anybody thinks it might be. Thanks Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted January 10, 2013 Report Share Posted January 10, 2013 (edited) You know this is a 10 year old thread on a W-body site right? Plenty of F-body sights out there or you can use the WHATEVER section. Winner for the biggest thread bump Ive ever seen:lol: Change your O2 sensor and Cat. converter Edited January 10, 2013 by rich_e777 Quote Link to comment Share on other sites More sharing options...
firebirdbob Posted January 10, 2013 Report Share Posted January 10, 2013 Actually I didn't but I did look for indicators of those things. I started by doing a google search form bad O2 Sensors Symptoms and a link to this thread popped up fairly high on the list. I didn't see any dates or the posts nor did I see that the original poster wrote that he had solved his problems. So I thought it was a on-going conversation/thread. I mostly jumped in to ask that Randy person if he ever got a resolution to his issues because his symptoms matched mine very closely. Since it is a drive train problem I'm experiencing, and because I know GM used a lot of the same motors and systems in their cars I thought it could hurt to ask. I've also tried several other forums and have found them unresponsive. It wasn't my intention to offend. Thanks for setting me straight. I'm seeking any good responses to my driveability issue. Thanks Quote Link to comment Share on other sites More sharing options...
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