200 XJ No Start

[Red99XJVT]

I may know what it is on the old engine the o2 sensors were downstream past the catalytic converters in the xhaust pipe, the new engine came with an exhaust manifold with the o2 sensors right up near the block but i used the old exhaust manifold that has those bungs plugged and the harness to those two o2 sensors near the blocks are still on the engine just not plugged in, but the downstream 02 sensors are connected, could that be the problem

Hard to read this... It sounds like you may have mix of Cali and non Cali emissions parts. Not sure what you are up against if this is so.

 

[Dekamdylan]

Well that sounds alot harder

 

[87manche]

you should have used everything that was on the old motor on the new one.

that stuff needs to stay the same so it matches your wiring/PCM in the chassis.

 

[Dekamdylan]

Ok, so swap the manifold, all sensors, the alternator is from the new one, the pcm from the old one, and the iat,map, tps from old?

 

[Dekamdylan]

Anyone?

 

[Dekamdylan]

Does anyone know what to do?

 

[87manche]

yeah, start looking for wires that are damaged from the swap.

something powered by the 5v rail from the PCM is most likely shorted.

 

[Dekamdylan]

Ok, will try, thank you

 

[Dekamdylan]

Ok, still does not start, have inspected some wiring but have not had a chance to do a very in depth check, It does give a p1698 until O unplug the TCM, then I still get a No Bus message, but only with the TCM unplugged do the gauges work. Even unplugging all trans sensors, ckp(cps), cam sensor, coolant temp, oil press, tps, map, iat, and still receivjng a no bus message, is there any wiring diagnostic/circuit tests that I can perform, I am pretty good with a multimeter

 

[Dekamdylan]

Can anyone here give me suggestions please?

 

[go1lum]

Cant remember but have you checked all the fuses in the pdc?

 

[Green Mesa XJ]

This may have been covered already. What year was the replacement out of? And were the old 2000 Xj sensors transplanted to the the new motor?

 

[Dekamdylan]

Same yr, 2000, not all sensors were swapped

 

[Dekamdylan]

Cant remember but have you checked all the fuses in the pdc?

Yes, fuses have been checked

 

[Green Mesa XJ]

It sounds like either a wiring harness problem or a bad sensor somewhere.
I not familiar enough with the 2000 to trouble shoot it but I'd start with the basics.
I may be missing some history you already covered. Your XJ had a bad motor was it running?
If you bought it broken maybe there was another problem the previous owner didn't mention.
The used motor swapped was known to be a good runner. If it the same emissions, both federal or both California, maybe go the opposite direction and put all the second motor sensors back since it was supposed to be good to start with. This won't work if they are different years or emissions.
The other thing to try is if your old motor was running is finish swapping the old motors sensors in the new motor.

If none of that works it sound more like a possible wiring harness problem.

In a search I found a write up about diagnosing no bus messages. It was fairly complicated.

I'm not sure what p1698 is about, something about wring to the computer or connection maybe.

 

[Dekamdylan]

Thanks for the ideas, you pretty much found exactly what I have
That I have to swap sensors and inspect wiring, thank you for the help

 

[Green Mesa XJ]

Thanks for the ideas, you pretty much found exactly what I have
That I have to swap sensors and inspect wiring, thank you for the help

I know You are probably frustrated trying to track the Fault down. I've found its better to go back to what worked last and try to figure it out from there. If you heard the new motor run and it the same year (if it's not the same year then its sensors are you're problem) I'd go with its sensors. If you old motor ran but was dying I'd go with its sensors instead just cause you know they are right for the car.

I've had the dumbest things stop a rebuild from being successful in the first try. Had a newer jeep ready to fire up and nothing but a click. The starter wire got bumped lose when tightening the engine mount bolt.

I'm s little afraid you engine harness is damaged some place that is a real pain to track down be easier to get a JY complete harness and be done with it. Be then I've never had much luck with wiring.

 

[Digger87xj]

I assume that when you took the engine out, the harness stayed in the vehicle?
If you swapped the underhood harness, You need to put the old one back.

I know that my sound stupid if you didn't, and you knew better but I've seen it attempted. Their thinking was the harness followed the engine.

Pictures of the engine and engine bay from various angles to highlight sensors and wiring would be a huge help in helping you find a solution.

 

[Red99XJVT]

From just following threads like this I would say that I think problems like this have been the result of a distributor not being installed quite right.

 

[Green Mesa XJ]

I assume that when you took the engine out, the harness stayed in the vehicle?
If you swapped the underhood harness, You need to put the old one back.

I know that my sound stupid if you didn't, and you knew better but I've seen it attempted. Their thinking was the harness followed the engine.

Pictures of the engine and engine bay from various angles to highlight sensors and wiring would be a huge help in helping you find a solution.

When a junk yard pulls a motor depending on who pulls it they usually cut the harness at some point,. If the harness in the vehicle now is fubar it might be easier to get one off as close a match as possible which can be pretty close if the harness part number is legible.
I thought from a earlier post a plug or some wires were damaged and repaired. I'm on my phone so it's a pain to scroll through.

The biggest thing to my mind is if the jeep was running before the swap. Then it's just sorting it out.