'93 pickup 22re 4wd. i did a timing chain on this truck and now i cant get the ignition timing set. the first problem is that the diagnostic port will not retard the timing like it should. there is no change on the timing light with it jumpered or not. Yes i have the right terminals. so that hinders finding the right spot. the second issue is that im sure something in the timing chain/distributor is off because i cant get the distributor set right, it wants to be timed between two gear sets. all the cam and crank marks line up like they should and the colored chains went where marks are. im at a little bit of a loss? Thanks

 

Is the idle set low enough??

The Ecu won't go to base timing if the revs are too high.

Is the TPS in good shape and in correct adjustment??

Same as above, the ecu won't go to base timing if it thinks that the throttle is opened.

 

Any progress on this??

 

Yes! I adjusted timing to 12 degrees btdc. runs much better but not perfict. The truck has another issue, i have the tps unplugged. with it plugged in it bogs out after its warm. i have replaced the tps twice and it is within spec. the temp sensor is also new. im contemplating changing the maf even thou it ohms out fine. lots of head scratching on this one. thanks for the help, totaly forgot about the tps not being plugged in. Thanks Neil

 

Dose anyone have an idea where timing should be set without the base map? Thanks Neil

 

I know that on my '87 22re, when the tps was out of wack, the timing was near 30 degrees advanced at idle.

When the tps was adjusted correctly, the idle timing dropped to 7 or 8 degrees advanced without moving the distributor.

 

i think that the base timing with the jumper in is something like 5 degrees at 750 rpm.

if you can't achieve that, troubleshoot it from there.

jacking the timing up in order to mask the problem may not be the most effective way to troubleshoot this.