LG4 cuts out at 2000 rpm at idle or cruise
#1
LG4 cuts out at 2000 rpm at idle or cruise
I've been having problems with my engine cutting out when held steady at or around 2000 rpms. Thecar doesn't seem to be down on power at all, has no acceleration issues, and seems to run fine at higher rpms. Vacuum checked okay, I have replaced the plugs, carb, wires, cap, rotor, coil,, and O2 sensor, checked all vacuum hoses, and I've checked the pickup coil, and the problem persists despite all of them testing okay.
Any ideas?
Any ideas?
#2
Moderator
![](https://www.thirdgen.org/forums/images/ranks/tgo10.gif)
iTrader: (14)
Join Date: Mar 2000
Location: Littleton, CO USA
Posts: 43,169
Likes: 0
Received 35 Likes
on
34 Posts
Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Is the car stock, modified, well maintained, neglected, high-mileage, rebuilt?
#4
Re: LG4 cuts out at 2000 rpm at idle or cruise
I'll go get that checked, thanks.
#5
Re: LG4 cuts out at 2000 rpm at idle or cruise
Re-replaced the plug wires... I hadn't crawled under the car and loomed the first set properly and one was burned. Rookie mistake.
Also replaced the CTS while I was at it.
I haven't noticed the stumble yet, but I haven't driven the car for extended periods yet. If it is there, it's much less pronounced.
Another issue though- before I replaced the carb, the car seemed to be stuck in fast idle. It wouldn't idle down when the throttle was nudged, but would when the a/c was turned on. I put a vacuum gauge on it and it seemed to have good vacuum. The remanned carb I installed seemed to idle even higher, so I adjusted the idle down to about 600 rpm on the throttle adjustment on the driver's side. The car has always needed the gas pedal to be pumped multiple times to start, even with the old carb (it doesnt start after the typical 1-2 pumps like it's supposed to) but it seems to need even more throttle input now. I would think it has something to do with the choke or fast idle can, but I find it hard to believe that both the factory carb and the remanned are misadjusted, especially considering that it ran fine with the factory carb for the past couple of years and I haven't messed with any adjustments on it.
So basically, my current symptoms with the rebuilt carb, tune up, and good vacuum (per the gauge) are the following.
It still shows good vacuum. It's kind of hard to start cold and always idles at 600 rpm, even cold, but once it's started it doesn't die. Drivability seems decent, though the choke light flickers at low rpm and it vibrates a little at idle, though rpms seem steady. I'm also getting pretty bad gas mileage (normally get 170 per tank, have been getting around 140).
Totally new to this ccqjet stuff and i feel a little overwhelmed... Any input is appreciated.
![doh](https://www.thirdgen.org/forums/images/smilies/doh.gif)
I haven't noticed the stumble yet, but I haven't driven the car for extended periods yet. If it is there, it's much less pronounced.
Another issue though- before I replaced the carb, the car seemed to be stuck in fast idle. It wouldn't idle down when the throttle was nudged, but would when the a/c was turned on. I put a vacuum gauge on it and it seemed to have good vacuum. The remanned carb I installed seemed to idle even higher, so I adjusted the idle down to about 600 rpm on the throttle adjustment on the driver's side. The car has always needed the gas pedal to be pumped multiple times to start, even with the old carb (it doesnt start after the typical 1-2 pumps like it's supposed to) but it seems to need even more throttle input now. I would think it has something to do with the choke or fast idle can, but I find it hard to believe that both the factory carb and the remanned are misadjusted, especially considering that it ran fine with the factory carb for the past couple of years and I haven't messed with any adjustments on it.
So basically, my current symptoms with the rebuilt carb, tune up, and good vacuum (per the gauge) are the following.
It still shows good vacuum. It's kind of hard to start cold and always idles at 600 rpm, even cold, but once it's started it doesn't die. Drivability seems decent, though the choke light flickers at low rpm and it vibrates a little at idle, though rpms seem steady. I'm also getting pretty bad gas mileage (normally get 170 per tank, have been getting around 140).
Totally new to this ccqjet stuff and i feel a little overwhelmed... Any input is appreciated.
Last edited by midnightfirews6; 10-13-2013 at 07:24 PM.
Thread
Thread Starter
Forum
Replies
Last Post
eightsixseven
Tech / General Engine
1
08-14-2015 03:09 PM