wavingpine11
NAXJA Forum User
- Location
- Central PA
This continues another thread I started, in which I was considering buying a '98 XJ, auto transmission, NP242, located here:
http://www.naxja.org/forum/showthread.php?t=935114
Initially, I thought it had a transmission problem, as when it was cold, it would drive really poorly, bucking when you tried to drive at more than an idle, not shifting properly. . . then the problem would clear up within a mile of driving while giving it short bursts of throttle.
I've had the opportunity to observe its dysfunction a little more now and I've picked up on these tidbits of information:
1) It starts fine. If I don't touch the gas at all from start through warm-up:
2) It idles fine for about a minute.
3) After that, it idles very roughly, seems like it's going to die, and smells especially rich during this rough idling stage.
4) It then surges up to above 1000 RPM, then slowly drops, and from that point forward, can be driven without any problem.
I hadn't tried a complete warm-up before. All I knew was that it drove very poorly, and that the symptoms would suddenly clear up. I've tried this warm-up technique several times with exactly the same results. If I let it smooth out its idle first, it will give me no issues when trying to drive it. Based on this, I'm thinking the idle air control valve. I tried to use Deep Creep (Sea Foam in a spray can) to loosen up crud on the valve, but I just sprayed it into the slit on the throttle body that leads to where the valve sits, with no generally helpful effect. My next move would be to take the valve off for a more thorough cleaning than would be possible using this possibly flawed approach. I'm sure I've seen threads on cleaning it here.
Anyone think I might be headed in the right direction here?
--wavingpine11
http://www.naxja.org/forum/showthread.php?t=935114
Initially, I thought it had a transmission problem, as when it was cold, it would drive really poorly, bucking when you tried to drive at more than an idle, not shifting properly. . . then the problem would clear up within a mile of driving while giving it short bursts of throttle.
I've had the opportunity to observe its dysfunction a little more now and I've picked up on these tidbits of information:
1) It starts fine. If I don't touch the gas at all from start through warm-up:
2) It idles fine for about a minute.
3) After that, it idles very roughly, seems like it's going to die, and smells especially rich during this rough idling stage.
4) It then surges up to above 1000 RPM, then slowly drops, and from that point forward, can be driven without any problem.
I hadn't tried a complete warm-up before. All I knew was that it drove very poorly, and that the symptoms would suddenly clear up. I've tried this warm-up technique several times with exactly the same results. If I let it smooth out its idle first, it will give me no issues when trying to drive it. Based on this, I'm thinking the idle air control valve. I tried to use Deep Creep (Sea Foam in a spray can) to loosen up crud on the valve, but I just sprayed it into the slit on the throttle body that leads to where the valve sits, with no generally helpful effect. My next move would be to take the valve off for a more thorough cleaning than would be possible using this possibly flawed approach. I'm sure I've seen threads on cleaning it here.
Anyone think I might be headed in the right direction here?
--wavingpine11