DROPT

what should i set my timing at to have the best chance of passing emissions? what does the fsm call for?

phildelfino

What kind of vehicle, motor, stock?

DROPT

oh yea, kinda left out that crucial piece of info.

89 truck, 22r all stock

MudHippy

Stock base ignition timing for the later model(after 1984)22R is 0°(which should be stated on the sticker under the hood). As in, no degrees BTDC or ATDC. That's only with the vacuum advance disabled, meaning both hoses on the distributor disconnected and plugged. With the vacuum advance operational, both hoses reconnected, it should be ~13° BTDC. If it isn't around 13° BTDC, or is around 8° BTDC, pinch the hose between the three way connector and the HAC(High Altitude Compensation)valve. If that doesn't move the timing to ~13° BTDC then the HAC valve may be faulty.

DROPT

i don't believe my truck came with the high altitude compensation

MudHippy

Yeah, I couldn't tell ya on that. But, there should be some kind of vacuum advance on it. Or is that different too? I dunno. It's pretty hard finding good info on that 22R. That was the best I could come up with anyway. Hope it helped a little.

If not, then keep askin' around, somebody might have something better.

Good luck!

DROPT

i found a download link to the fsm. it says it should be at 12degrees btdc with the vacuum advance plugged in and at 0 with it unplugged and capped