ahickman

Working on an 86 22RE auto. Just bought it and it had a blown HG and no exhaust. Replaced the exhaust and manifold gaskets. Replaced the HG and buttoned it back up. Fired up, but ran idles poorly. Timing is good. Compression is 162, 162, 155, 155. Started pulling plug wires to see if a cylinder was dead. #3 has no effect on running engine. All other cause it to stall out. Thought I had a bad fuel injector, but after pulling them out, testing them and then switchin them around, the problem still exists on #3. Spark is present at #3, but kinda seems weak as compared to others. Also swapped the fuel injector connectors (#2 and #3) and problem still at #3. kinda at a loss as to what to look at or test next. Ohmed out the plug wires and they are all good. Stumped!

The4runner

Well you should check the cap and rotor and then is you can try to do a cylinder leak down test

ahickman

Cap and rotor are good when check with ohm meter. If the #3 cylinder is giving 155 psi on compression test, what would the leak down test tell me in terms of why it is not providing combustion?

deserthound

Just a shot in the dark. How are the cam lobes on #3. Good compression indicates valves are closed ok but if the cam doesn't open them properly, the cylinder won't make power. I also agree the distributer cap is still a potential source of the weak spark. Ohming it is one thing, but that doesn't check the rotor to plug wire contact gap, which if opened up would produce a weak spark. Then, a weak spark may not be able to fire under compression.

Junkers88

As dumb as this may sound I'd check the gasket between the head and the intake. I had a very similar problem and after doing all kinds of other crap I found out the intake gasket was blown on number 4. It did the same thing your's does when I pulled the #4 plug wire...... nothing.

TOYOTA 1

I'm having the same problem, except on #2...

i tested the ends of the wires going to that injector, and only one of those wires have power? but the wire looks fine all the way to the firewall(thats as far as i checked)
I'm stumped lol..

subed and a bump

abecedarian

Mentioned elsewhere:
The fuel injectors are tied together in pairs, 1/2 and 3/4 (iirc). Then elsewhere the two pairs are likewise spliced together, even though the separate banks have separate driver circuits in the ECU (). The splices are crimped on, not soldered and are known points of failure. Also, one terminal in the injector plug is 12v constant, the other should also measure 12v but is switched to ground by the ECU to fire the injectors. An oscilloscope or noid light should help you track down if the injector is getting pulsed.