Lean Idle condition; HELP
04-27-12, 04:59 PM
#76
k. So I unplugged the plug from the ECU and there is no more voltage on the secondaries green wires to the ECU, but if I swap ecu's or plug it back in there is still a lower 11.1-11.3voltage reading on both green wires to the secondaries.
So assuming my wiring harness is fine, what exactly tells the ECU when and how long to fire the injectors. Because something is fucked. I'm so close to going Weber, and I would have a year ago if I didn't live in the worst state in the Union.
So assuming my wiring harness is fine, what exactly tells the ECU when and how long to fire the injectors. Because something is fucked. I'm so close to going Weber, and I would have a year ago if I didn't live in the worst state in the Union.
04-29-12, 04:43 PM
#77
Swapped CAS: same issue. Attempted to run w/o BAC: same issue. I think it has to be the wiring harness. I cant think of anything else, and I'm too poor to take it anywhere. Especially considering the last shop I took it to, took every dollar I had and left me with the wrong diagnosis.
05-06-12, 04:17 PM
#78
So I 've got it running very well now, but the irratic idle condition comes and goes. One weird thing I have noticed that I'm driving it again. I was going 30 in 3rd gear almost no throttle input, and the car was going in to decel mode. I know it's a shutter valve that cuts fuel on the FB, but noit sure what controls that on the FC. Maybe that's part of the issue. It's hard to describe, but if i'm driving at really low load and say 5% throttle its fine, but from 5-8% throttle it goes into decel mode and cuts fuel to a rotor. So friggin weird. Other than that it's running and driving and carving canyons again. Just don't stop at a red light or get caught in traffic with it. LOL Any ideas?
05-06-12, 07:43 PM
#79
Even though no one reads this thread anymore I'm going to keep posting until I get if fixed. LOL Anyway one thing I forgot to mention is that when it starts up cold it revs to 4500 RPM instead of 3k, and if I start it in gear it still revs to 3k before dying.
05-07-12, 01:16 PM
#82
Rotary Freak
The attachment is from the free online series four trainging manual.
If your driving along at a steady speed, say fifty mph. You let off the pedal. Fuel is then cut to one or both rotors. If you leave your foot off the pedal the injectors will once again start firing when the rpms are?? approx 1100-1200 rpm, if memory serves.
The TPS has a LOT to do with this happening. You might try disconnecting the TPS and see how that effects whatever problem your having. No TPS I think would result in the cut to the rotors not happening. I think thats so.
If your driving along at a steady speed, say fifty mph. You let off the pedal. Fuel is then cut to one or both rotors. If you leave your foot off the pedal the injectors will once again start firing when the rpms are?? approx 1100-1200 rpm, if memory serves.
The TPS has a LOT to do with this happening. You might try disconnecting the TPS and see how that effects whatever problem your having. No TPS I think would result in the cut to the rotors not happening. I think thats so.
05-12-12, 06:05 PM
#83
With the TPS unplugged there is no cut, but there it makes absolutely no attempt to idle at all.Just immediately dies. With it plugged in it at least bounces around for a minute between 500-1000 RPMs before it dies.
So yesterday I put about 400 miles on the car and noticed something very strange. When I am full throttle, somewhere around 4500 RPM the stock coolant temp gauge drops to zero. Then goes back to normal when I let off the throttle. It's a very fast response too, like it loses power and just turns off. It's not a slow drop It literally looks like it's just turning off. The other thing I noticed was that the tach was from an automatic. I couldn't tell before that there is a faint PRND on the tach. I just always assumed the shift up light was out.
So yesterday I put about 400 miles on the car and noticed something very strange. When I am full throttle, somewhere around 4500 RPM the stock coolant temp gauge drops to zero. Then goes back to normal when I let off the throttle. It's a very fast response too, like it loses power and just turns off. It's not a slow drop It literally looks like it's just turning off. The other thing I noticed was that the tach was from an automatic. I couldn't tell before that there is a faint PRND on the tach. I just always assumed the shift up light was out.
05-12-12, 09:19 PM
#84
talking head
somewhere around 4500 RPM the stock coolant temp gauge drops to zero
while it may be nothing sinister ( dash indication from rear of block sender ) like poor continuity of the sender wire itself
it may also be indicating a wider issue with voltage or earth potentially effecting a range of instruments
( as mentioned on post 26 about the 12, 5v and earth bundles crimps for the ecu wiring )
im betting this an earth offset issue ,, and very likely related to why you have 3 TPS that seem to go dead band or open circuit at part stroke
ie,, the issue is not the tps itself,, but the ( usually black/red ) earth side of the instrument losing connection or having significant resistance on its path to battery
05-12-12, 09:33 PM
#85
Yes, on the dąsh. I'm thinking its the wiring harness. I looked everywhere and nothing looks awary. The Coolant sensor on the block is firmly connected to the wiring harness. I just replaced the coolant temp sensor on the back of the water pump about ten minutes ago. Pretty soon I'll have all brand new electronics and then I'll know for sure its the harness. I've looked everywhere and can't find a short anywhere. At a loss.
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2nd Generation Specific (1986-1992)
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