96 XJ - will start but dies right away

[TRCM]

Mine is a 96 Sport, and I do have an OBDII port also under the dash.

Well, put in new plugs, cap, rotor, wires, and a new TPS. I also cleaned out the throttle body (not really dirty at all), and she fires right up now like she should. Only thing not completely normal, is she is a little slow to drop to a normal idle, since the IAC has to relearn what is needed (I adjusted it some when it was off the vehicle).

I can get the codes now using the key. Not sure what went on, but it works now.

How do I find out if I have the 97 harness & computer as well. May make future issues easier to fix knowing that.

 

[Ecomike]

Now days with all the electronics, mixed with used marginal spark plugs, rotor and cap, they can work fine one day and suddenly not the next, with no easy cut and dry way of testing to verify if they are good or bad (cap, rotor and plugs). So if they look just like they did 1 month, 3 or 6 months ago, we go looking for bad sensors and wiring issues right off, when it is simply a matter of they just got a little too warn to cut the mustard anymore.

I relearned that lesson myself last year.

 

[TRCM]

Here's another thing I just remembered.

When it wouldn't start, the fuel pump also didn't cut off, like it never built up pressure (even though fuel pressure was fine when I checked it).

Now, the fuel pump kicks on for about 2 seconds then shuts off like it should.

I just took it down to AZ to get the codes read with a reader.....no codes are present, and all parameters are within spec when the engine is running as well.

Maybe it was the plugs/cap/rotor, but since I also replaced the TPS, and disconnected/reconnected a lot of stuff, there's no way to really know for sure aside from putting the bad TPS back in.

And the cap/rotor weren't all that bad, but the plug looked nasty (probably from me trying to start it so much to avoid a tow home), but they had opened up to ~ .045.

 

[8Mud]

Hopefully it was a gremlin in your TPS and is now good. Just in case, take the air box off the TB and spray some spray oil into the IAC air opening with the engine running. I do that a couple of times a year, it helps keep the semi solid trash from building up inside the IAC ports.

I always start with no pedal, full pedal or WOT can mess with fuel delivery. If you need any pedal to start, something is wrong.

Mine is an early 96 and actually has some 95 parts in it (my front O2 is a 96, my rear has a 95 connector) and it's an export model. I have a security box as part of the automatic door openers that has given me issues. It has a cutout for the ASD relay circuit and sometimes doesn't deliver enough current to make the asd relay work correctly. The ASD relay would sometimes work, sometimes not work and sometimes kind of work.

I don't know if yours has the extra security module in the ASD circuit incorporated into the door openers or not. If it does, it may give you issues like mine did. My ASD relay would buzz and not fully engage on occasion and acted like a marginal CPS.

 

[TRCM]

I'll keep the ASD issues in mind, as mine did/does have the security stuff, I just don't use it

 

[Digger87xj]

10/96 build date is a 97.

New model year builds starts in august.

That is an automotive manufacturing standard.

Check the 10th digit of the VIN; if it's a T its a 96.. a V is a 97.

 

[TRCM]

Well, the 10th digit is a 'T', and the emissions sticker on the firewall says 96 truck.

Sticker on door says 10-96 for build date