Whiplash Willy

I just bought a 93 4x4 pickup (22re w/166k) and am trying to solve its rough idling problem. The idle is pretty rough hot or cold, but things get better as I give it some gas. If you listen to the exhaust, you can hear the exhaust coming out surges like it is missing. There is also a decent amount of moisture that comes out of the exhaust when it is cold. I tried going through DEQ, and failed the idle test because of high HCs. I had 3304 when I should have around 220 I have done/replaced the following, but nothing has fixed the problem.

New Distributor Roter, cap, and wires.
New Spark Plugs
New Air Filter
New Fuel Filter
Remanufactured Injectors
Set Timing and confirmed it is with specs
Adjusted valves to Intake 0.007 & Exhaust 0.011 (Cold)

Also, I don't have any ECU error codes. One weird thing I noticed when I was testing the injector wiring is that there was continuity between the black/red and both the white and the white/red wire. There is also continuity between the white and white/red wire. From my understanding, the black/red wire is the ground that goes to all of the injectors. The white wire is the 12v wire for Injector #2 and #4. The white/red wire is the 12v for the #1 and #3 injector. I didn't think there should be continuity between any of the different color wires, but I am not sure.

Any ideas of what I can try next? I have until the end of the month before my tags expire.

abecedarian

disconnect the plug on the cold start valve and see if that corrects the rough idle, if so, then the cold start time switch is likely defective

abecedarian

also, even though there are separate wires for pairs of injectors, they are connected together elsewhere in the harness so they should be continuous- all 4 injectors fire at the same time.

motoriderbc

3300 ppm HC is a bad misfire. You probably have a dead cylinder. It's not likely an injector problem since you have plenty of HC in the exhaust. I wouldn't look at sensors/ECM issues to start. You likely have a mechanical fault with engine ie burnt valve, blown intake gasket, badly blown headgasket, ignition fault etc etc

Might want to post up the rest of the readings to help give more direction.

Your next step should be to isolate which cylinder is not firing.

Whiplash Willy

Thanks for your responses! I tried unplugging the cold start injector, and it had no effect. I will try an compression tonight and see what happens. How can I test for a blown intake gasket?

I unplugged the spark plug cable from each cylinder, one at a time, while it was idling, and each one negatively effected the idle.

KevinInSac

Just curious, what RPM are you idling at anyway?

Whiplash Willy

It is idling at 750rpm.

Junkers88

I had the same problem, failed my emissions test for the same reason and was told I had a dead cylinder. Comp checks came out at 150 +/-3 per hole. I ran some seafoam through it and found a busted intake gasket between the head and the little tubes that go from the plenum. 3.15$ worth of gasket and she runs like a top. Of course I already replaced and repaired just about the same amount of stuff that you did.......

I'd say do a compression check and if it comes back ok on compression then start looking for a busted gasket.