nick2690
NAXJA Forum User
- Location
- oregon/washington
I have a 1990 XJ with the stock 4.0 and it starts and runs fine. My problem is that if I put it in drive or turn on the lights it dies. Not really sure where to start so any help would be awsome.
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XJ runs in park but not in drive
- Thread starter nick2690
- Start date
Could very well be a voltage problem. Make sure your battery has a good charge. Also use a meter and see what you battery and alternator output is. With modern electronics if voltage dips to much things quit functioning. Once you know what your output voltages are, leave your volt meter connected to the battery and have someone turn on the lights, what is your battery voltage then? Hope this helps or at least gets you going in th right direction.
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
Really a broad range of possible problems.
As the title says "park" and not neutral I'm going to a**ume automatic.
The NSS shouldn't have any effect on running. I does interrupt the starter relay ground except in PARK and NEUTRAL to prevent the starter from cranking the engine in gear, but there isn't an ignition interrupt built into it.
Lets go real basic: when running in PARK, after about 20 minutes of operation--in your case sitting and idling, what is the engine rpm with an external tach--not the dash tach. When the engine is fully warmed up and you put the transmission in DRIVE the engine should be idling at 700-750 rpm. When the engine isn't in drive it will be idling higher, but there is no specification for it. However, if the PARK/NEUTRAL idle is too low, the engine may be stalling out when you put the transmission into gear. So, check out the idle and post up what you find.
Another thing is the crank sensor aka CPS/CKP. If you have bad engine mounts its harness could be shorting out when you shift into gear and the engine torques. The crank sensor is mounted high on the driver's side of the bellhousing and the harness runs up from it. Also would be a good idea to unplug and plug it back in a few times to renew the connection. Without the signal from the crank sensor the ECU/PCM will not fire the spark, so any interruption in that signal and the engine dies.
There are critical grounds to your dipstick tube--the ICM (ignition control module--the thing the coil is clipped onto); the ECU/PCM; and the o2 sensor as well as other things ground there. Also, there is a braided strap that runs from the rear of the head, driver's side, to the firewall. That is the ONLY ground for the unibody, and it is critical. I recommend replacing the strap with a 4 or 2 gauge cable. For ALL the grounds, strip it down to bare metal, treat with an anti-corrosion agent, and make the connections TIGHT.
That should give you a few things to work on.
Post up what you find.
Good luck.
PS--welcome to
!
As the title says "park" and not neutral I'm going to a**ume automatic.
The NSS shouldn't have any effect on running. I does interrupt the starter relay ground except in PARK and NEUTRAL to prevent the starter from cranking the engine in gear, but there isn't an ignition interrupt built into it.
Lets go real basic: when running in PARK, after about 20 minutes of operation--in your case sitting and idling, what is the engine rpm with an external tach--not the dash tach. When the engine is fully warmed up and you put the transmission in DRIVE the engine should be idling at 700-750 rpm. When the engine isn't in drive it will be idling higher, but there is no specification for it. However, if the PARK/NEUTRAL idle is too low, the engine may be stalling out when you put the transmission into gear. So, check out the idle and post up what you find.
Another thing is the crank sensor aka CPS/CKP. If you have bad engine mounts its harness could be shorting out when you shift into gear and the engine torques. The crank sensor is mounted high on the driver's side of the bellhousing and the harness runs up from it. Also would be a good idea to unplug and plug it back in a few times to renew the connection. Without the signal from the crank sensor the ECU/PCM will not fire the spark, so any interruption in that signal and the engine dies.
There are critical grounds to your dipstick tube--the ICM (ignition control module--the thing the coil is clipped onto); the ECU/PCM; and the o2 sensor as well as other things ground there. Also, there is a braided strap that runs from the rear of the head, driver's side, to the firewall. That is the ONLY ground for the unibody, and it is critical. I recommend replacing the strap with a 4 or 2 gauge cable. For ALL the grounds, strip it down to bare metal, treat with an anti-corrosion agent, and make the connections TIGHT.
That should give you a few things to work on.
Post up what you find.
Good luck.
PS--welcome to
!lawsoncl
NAXJA Forum User
- Location
- North Idaho
That's my bet as well. The headlights get their ground through this strap, and putting it in drive will tweak the orientation of the braided strap. Very common problem.
nick2690
NAXJA Forum User
- Location
- oregon/washington
thanks guys i will give these a try and let you know what worked
davedanger
NAXJA Forum User
- Location
- Auburn,CA
I had a similar problem with my 88.
The cure was replacing a corroded connector in the B+ relay socket. Relay is #2 in the group on right, above front wheel. Relays are all the same so they can be exchanged to test.
The cure was replacing a corroded connector in the B+ relay socket. Relay is #2 in the group on right, above front wheel. Relays are all the same so they can be exchanged to test.
mxracer624
NAXJA Forum User
- Location
- Hemet ca,
Had the same prob with my 89.. the 4 relays on the driver side need to be replaced. They should all be replaced at the same time. I guarantee that's your problem.. my jeep would run, then as soon as I turned on the lights or hit the brakes or used what seemed like any electricity it would just die. Replaced all 4 out of a donor vehicle and fixed the prob. Good luck!
JJacobs
NAXJA Forum User
- Location
- Fort Collins CO
mxracer624
NAXJA Forum User
- Location
- Hemet ca,
I guarantee, that is a fix for a problem... not saying his problem, just one in general Haha. Better? Lol
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
Or "Double your money back if not satisfied with the free advice!"
