MadPSI Posted July 28, 2008 Report Share Posted July 28, 2008 '92 CSS 3100... I'm trying to pinpoint what exactly is wrong with this car. For the last three months of daily driving it has been intermittently dying whenever my throttle is at 0%. This usually occurs when starting, idling, and decelerating from slower speeds. I can drive the car around all day long if I keep the revs above 500RPM by resting my foot on the throttle when coming to stops and such. The strange thing is that the above condition only occurs about 50% of the time. Sometimes I can start and drive the car around like normal without any added throttle, other times it won't start or idle without the tiniest bit of throttle applied. Sometimes it starts fine when cold and starts dying when it gets hot, sometimes the exact opposite occurs. It's totally random. The strange thing is that when it decides not to idle, I can give the gas a few stabs to get it going, then slowly bring the revs down to around 500, after holding the revs there for a few seconds, I can take my foot off and it'll stay there. This is baffling... Stuff I've done already: - New FP - New CPS - New TPS - New IAC - New Plugs & Wires - 4 out of 6 fuel injectors replaced... - 11ty billion idle relearns performed Every time I lose an injector it totally kills the car, it usually blows the injector fuse and the car gets towed home, so I'm sure it's not a faulty injector. ...however... What exactly is a "stuck" injector? Would a stuck injector on one cylinder cause the car to die? If so, how does one check for a intermittently stuck injector? Does it usually take things like coil packs and/or the ICM 3 months of daily driving from showing signs of failure to finally die completely? I've had things take a week or so before they totally quit, but I think this condition could go on forever if I let it... Thanks for any insight anyone has... Quote Link to comment Share on other sites More sharing options...
Addicted to eaton Posted July 28, 2008 Report Share Posted July 28, 2008 My car did the that to But sometimes it wouldn't die it would idle like it had HUGE headers then die. It was my map senser Quote Link to comment Share on other sites More sharing options...
MadPSI Posted July 28, 2008 Author Report Share Posted July 28, 2008 My car did the that to But sometimes it wouldn't die it would idle like it had HUGE headers then die. It was my map senser I'll take a look at that. When I can get it to idle, it sounds like it has a huge cam, I actually prefer the sound it makes, but I know it's not normal... Quote Link to comment Share on other sites More sharing options...
Addicted to eaton Posted July 28, 2008 Report Share Posted July 28, 2008 yeah same her. I got a Check light too. I pulled up at a stop light and. Sometimes it would idle for a min and start Jumping around and die. it would go down to 250rpm al the way to 1,400 rpm Quote Link to comment Share on other sites More sharing options...
Brian P Posted July 28, 2008 Report Share Posted July 28, 2008 this is a '92 car with a 3100? or 3.1? I had a stuck-open EGR cause somewhat similar issues, but also gave it a very rough idle. Quote Link to comment Share on other sites More sharing options...
Breakdown Posted July 28, 2008 Report Share Posted July 28, 2008 '92 CSS 3100... I'm trying to pinpoint what exactly is wrong with this car. For the last three months of daily driving it has been intermittently dying whenever my throttle is at 0%. This usually occurs when starting, idling, and decelerating from slower speeds. I can drive the car around all day long if I keep the revs above 500RPM by resting my foot on the throttle when coming to stops and such. The strange thing is that the above condition only occurs about 50% of the time. Sometimes I can start and drive the car around like normal without any added throttle, other times it won't start or idle without the tiniest bit of throttle applied. Sometimes it starts fine when cold and starts dying when it gets hot, sometimes the exact opposite occurs. It's totally random. The strange thing is that when it decides not to idle, I can give the gas a few stabs to get it going, then slowly bring the revs down to around 500, after holding the revs there for a few seconds, I can take my foot off and it'll stay there. This is baffling... Stuff I've done already: - New FP - New CPS - New TPS - New IAC - New Plugs & Wires - 4 out of 6 fuel injectors replaced... - 11ty billion idle relearns performed Every time I lose an injector it totally kills the car, it usually blows the injector fuse and the car gets towed home, so I'm sure it's not a faulty injector. ...however... What exactly is a "stuck" injector? Would a stuck injector on one cylinder cause the car to die? If so, how does one check for a intermittently stuck injector? Does it usually take things like coil packs and/or the ICM 3 months of daily driving from showing signs of failure to finally die completely? I've had things take a week or so before they totally quit, but I think this condition could go on forever if I let it... Thanks for any insight anyone has... My car did this crap to me and it made me want to push it off a cliff. Injectors, idle sensor position, new idle sensor . . . . it was a shopping list of horror, I think that the new owners have it working better. The only thing that really helped is getting some cleaner pumped into the system, the car was just loaded with carbon! These engines seem to always do this, and I haven't heard of the 3100 pulling this, so I would assume it's the 3.1L. I hope you have better luck than I, that's all I'll say. Quote Link to comment Share on other sites More sharing options...
MadPSI Posted July 28, 2008 Author Report Share Posted July 28, 2008 Sorry, it is a 3.1L I guess. I don't really know the difference between the two... I'll consider a top-end cleaner, but you'd think that if excessive carbon buildup was the problem then the car would consistently act the same way. It's like there's a pixie living in my car with a big switch that says "make car run perfect" and "make car run shitty", and it is turned on and off randomly throughout the day... Quote Link to comment Share on other sites More sharing options...
Breakdown Posted July 28, 2008 Report Share Posted July 28, 2008 Sorry, it is a 3.1L I guess. I don't really know the difference between the two... I'll consider a top-end cleaner, but you'd think that if excessive carbon buildup was the problem then the car would consistently act the same way. It's like there's a pixie living in my car with a big switch that says "make car run perfect" and "make car run shitty", and it is turned on and off randomly throughout the day... There's an easy tell. The 3.1L has a flat top and engraved 3.1 Multiport FI engine or something or other but in huge block letters but inset , especially the 3.1L. The 3100 series has 3100 and less obvious engraving (see below) they are quite easy to tell apart to the eye. Quote Link to comment Share on other sites More sharing options...
Brian P Posted July 28, 2008 Report Share Posted July 28, 2008 it's hard to say exactly what it is without looking at the data from all the sensors, but I can say it COULD be: - O2 sensor - MAP sensor - EGR - Intermittent vacuum leak, maybe from a failing intake or throttle body gasket, or loose line - FPR occasionally leaking excess fuel into the motor thru the vacuum line - Another injector issue (unlikely) 3.1: 3100: Both engines share the same architecture but are very much different. Quote Link to comment Share on other sites More sharing options...
MadPSI Posted July 28, 2008 Author Report Share Posted July 28, 2008 Alright, I definitely have the 3.1L, not the 3100... I'll check FPR, EGR, and MAP (swap out spares) and see if that does anything... Quote Link to comment Share on other sites More sharing options...
Brian P Posted July 28, 2008 Report Share Posted July 28, 2008 Yeah, check also all vacuum lines and the PCV valve hose at the back of the engine, under the MAP sensor. It's a little tough to see and the PCV line runs under the upper intake manifold, but see if you find any cracks, splits, etc. Does the engine act up when it's under operating temp too? Or only once warmed up? Quote Link to comment Share on other sites More sharing options...
ismellrealbad Posted July 29, 2008 Report Share Posted July 29, 2008 500rpm is very low. issue is intermittent at idle or coming towards idle on decel. its a fuel or vacuum issue, most likely small vacuum leak imo. Quote Link to comment Share on other sites More sharing options...
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