Wade

I was getting a little bit of a "ping" under low RPM and moderate load, so I decided to take another look at my timing. I'm using an old Craftsman Dwell / RPM meter to set my idle, but it seems way too low at 750 rpm.

Anyway, set at 5 BTDC with the connectors shorted, it runs ok and advances to about 12 BTDC when I remove the connector jumper. However, when I use my headlights, windshield wipers, and vent fan, the idle gets very rough. Plus, I still have a little bit of a ping?

Anyone have any ideas? I'm a little bit of a perfectionist, but it should run smother than it is now and the ping kind of gets on my nerves.

Thanks...Wade
1990 4x4 truck w/22re
5spd manual

Wade

Does anyone have any ideas...bump

4Crawler

iTrader: (3)

Bump the idle speed up a little. I generally run mine between 800 and 900.

farmerj

The idle speed is in the emission sticker on the hood along with the timing info. If your 90 is the same as my 88, it should be 750. It will effect you mileage in town to raise it up.

Any computer controled system is just going to ballon one problem into many to get you an increased idle speed unless you can reprogram your computer.

your ping is pre-ignition. For now, try going to a higher octane fuel to see if you can get rid of the ping.

Pre-ignition is either from carbon build-up in the cylinder or else a timing issue. Something would have be advancing the timing to get your pre-ignition. Timing chain would retard timing if it was stretched.

I am still learning the fine details of the 22REC to completely understand the ignition and timing system at the moment, so some of this is in general.

Try the fuel first in a a higher octane. Go to an 89 first, and if that doesn't fix it, try going to 91 octane.

Do you normally try to fill the tank at the same gas station? if so, try a different gas station for a couple of tanks.

4Crawler

iTrader: (3)

Actually, the ECU has not a lot to do with the idle speed on the 22REC engine. You just adjust the idle air screw to set the air coming in and the ECU monitors the O2 sensor and AFM to adjust the fuel to match. My 22REC will idle at 750, it is just a little rough (I have a TRD cam in mine that probably affects that to some degree). So I generally run 800-850 on the idle, works fine and the CA smog police are fine with that, I think they allow up to 1000 or so. Also, I live near sea level and find that at the 800-850 base idle, when I get up to 8000-10000' in the mtns. wheeling, my idle speed drops but stays at a reasonable 500-600 RPM. If I start out at 750 at sea level, the idle can drop to 400 or lower up high, then I have to either bump it up, or hit my :fast idle button". The 22RE engine has a couple of VSVs to bump up the idle speed when you try to steer (valve in the p/s pump) or turn on the A/C, but nothing when you load up the alternator.

On later model ODB-II controlled engines, I think things like idle speed and timing are set and controlled by the ECU. You can't even adjust them externally.