I am working on my 89 xj 4.0 and my timing light says that its retarded 22 degrees. I know that the timing is set by the pcm but i also know that it should not be that retarded. Any help.would be awesome.

 

At what RPM, and you do have it on #1? Pardon that question but..

 

At an idle. About 700 rpm and yes its on number one. I don't understand.

 

Well, if nobody better qualified is going to chime in....that may be correct and as it should be. For emissions the retarded timing at idle may be best. I assume you would have mentioned it if it wasn't advancing with higher RPM.
Older Fiat 124 sport Spider had 2 sets of points, one retarded and one advanced, it switched them with a thermal switch.....

 

If it runs decent its right. The only thing that will throw the timing off considerably is indexing the distributor wrong. Well, a bad knock sensor will retard it too.... mmmm.

 

Ok so i will try it at a higher rpm. But with a bad knock sensor retarding it, it would run hotter. Which would explain my next problem with it always running a little warm and a little bit of backfire when i shift. I have changed it over to an open system cause all i ever did was fight the old closed system and that stupid recovery tank. Thanks for all the help. Keep them coming.

 

Ok so tried it again at 2000 rpm and got about the same. Any more ideas.

 

See post #5. Slick is pretty slick! By indexing I think he means if it's off a tooth. Somewhere you should be able to find where the rotor should point when the engine is at TDC. Probably a good thing to do first. My knock sensor is above my left ear and works fine. Don't know where yours is!

 

I will check tdc and see where the rotor is and get back to ya.

 

Haha thx

 

Ok at #1tdc the rotor is aligned with #1. Like it should be. But timing is still retarded 22 degrees. No mater what rpm it does not change.

 

This could be caused by a bad knock sensor. The knock sensors job is to retard the timing when it senses detonation. The factory ones are very fragile.

 

Ok i think i will try that. I sure do appreciate the ideas. Do you think that running retarded could cause it to run hotter than normal? Thanks for your help.

 

Yes

 

Thanks again. I will get one and see what happens.