Okay, so my buddy and I were out running the **** out of my '83 GSL, he was driving but not doing anything I wouldn't do... redline shifts, running mostly between 5-7K RPM for about 15-20 minutes, then he pulls over so I can drive back. As I'm getting out, we realize it won't idle right, it's sputtering and he's gotta stay on the gas to keep it running... there's a couple of "uncle Buck" style back fires while he's goosing the throttle to keep it going.

Finally he revs it up and I switch his place quickly before it dies and now I'm trying to keep it running. It'll run fine and strong as long as you give it gas, but it sputters (and would probably die if I let it) at idle. WTF?! Anyhow, it drives just fine as I head for home and by the time I get to the next stop sign (about 5 miles) everthing's fine.. including the idle! I took it as a sign from God and dropped him off at his place. On the way back to my house it happended one more time at a stop sign, but again later in the trip all was fine again. I let it idle for a few minutes in my garage and everyting was still okay, but now I'm a little gun shy of it... any thoughts on what the problem could be? Why would it fix itself and then crap out again and then fix itself once more? The loud backfire was most alarming as it has NEVER done that before. Please help!

I'm running the stock Nikki, no cat, and my only other mod is an electric fan.

 

hey..
i don't know what's wrong but i'm having the same problem ( without the backfiring)... mine will idle fine sometimes and other just barely stay at 500 rpms!!!! it's the exact same thing yours is doing.. i'm wondering what it is... and mine is all stock besides the k&n filter..

 

I dont know if I am right, but I think it might be something to do withe the cooling. Because sometime with the choke on, it will shut off early and the car starts to sputter. Then you drive it, then it runs smoothly again.

 

Whats up, brotha?

Anyways, about the weird idle thing....I think it's just the nature of these cars. If you drive it hard for a while, it wants to STAY driving hard.

If you drive link a grandma, it should stay the same that way.

If it idles a little goofy, just pull you choke out a bit. My car is pretty stock too, just that K&N.

Seems it's just the way the car's are. A little personality.

 

and u got to love that personality ... that's what i thought cause when i drive it hard it idles good.. then if i drive it hard and sit at a red light for a long time it starts to act up ( like it's pissed off at me for not running the red light). or when i turn the heat on somtimes..
thanks... ( i'm not trying to steal the thread just had the same problem)

 

I was thining maybe some kind of needle & seat problem in the carburetor... like maybe when my buddy went for 7K down to idle and the demand for fuel went away, the needle didn't seat itself properly, so the fuel kept flowing, which is why we had to rev it up to run and then all that unburnt fuel in the exhaust would cause a backfire... after I got to driving it again, perhaps it became properly seated again.

Does this theory have any merit? I'll pull the spark plugs out tonight and see what they look like. I did check all the plug wire connections last night when this happened and everything was as it should be.

 

Sounds plausible. Sometimes when you run a rotary hard and then quickly back off the gas, they get a bit loaded up and it takes a while to clear 'em out. I've run into that before. The motor will kind of "surge" and buck for awhile until it clears out and gets "happy" again.

 

Mine dies right after the choke shuts off and then start up and runs fine. I was thinking it was just the sudden rush of air? Im not sure. But this morning, it would ifdle for **** after I tried to restart it. It was barely idling and bucking and jumping all over the place, then all of a sudden, it just smoothed out after like 5 minutes of barely running, then it magically ran fine?

~T.J.

 

Well, I think I'm going to go with my carburetor theory. Maybe I can use this as an excuse to buy the intake manifold I need to put my 45 DCOE on there now!

Later folks!

 

Alright, I fugured out our Carb problem.

I was reading through my Racing Beat Rotary Performance Technical Manual, under the Intake Section.
It says that the stock carb used in these rotaries, are very good performance wise. But they have a very poor low RPM fuel fixure, which will cause the car to act up and shut off when the choke releases.

That is why, when you hit the gas like at a stoplight or something you can feel a lag. Becasue these carbs have very poor throttle response, alond with bad gas milage.

Thomas Stifter

 

I know what you're talking about. It is almost like a switch is being flipped in the system somewhere. The thing is, it rarely happens when the weather warms up. Could it be that the ambient temperature has something to do with it?

 

Oh yeah, definately.

The more cold air that is let into your carb, the more chance you have of this happening.

Thomas Stifter

 

ASEmaster, judging by what you described I'm sure it was just your carby flooding up. God knows I had enough experience with it when I had the stock carby. It could just be a worn needle and seat or maybe a bit of debris got caught in there.