So, I have a 91 4x2 DLX Extended Cab 22re and I have a misfire on cylinders 1 and 3. I bought the truck originally with a misfire in cylinder 3. I threw a new injector in and it cleared it up for about 30 miles, then again misfire on that cylinder. Got another injector, threw it in, fixed it again, this time for only about ten miles.

Things I have done:

- Compression test, all 4 cylinders test around 180
- plugs, wires, cap, rotor
- igniter
- two new fuel injectors
- tested injectors and they have pulse
- "new" junkyard computer (computer was out of virtually the same truck, compared year, model, emissions, drivetrain and tranny)
- removed the cat (thought it might be clogged up and creating too much back pressure)
- checked all the grounds, they are all good
- no CEL or stored codes

I'm at my wits end with this. Any insight would be helpful.

 

I have had a similar situation on my Number 1 cylinder. Mine turned out to be a bad connection on the fuel injector itself. Try wiggling the connector while it is idling and see if it cuts out.

If you have the wire clip that holds the connector on, they can be brittle and not make the best of connections. They later improved the connectors that have a little press tab. Not sure which year they changed. The little press tabs are the better one.

 

Mine has the press tabs.

 

Might want to check the splices in the wiring itself.

http://forum.ih8mud.com/79-95-toyota...lem-i-had.html

From 4crawler's site:

 

I'm gonna have my mechanic take a look at the splices. It's too cold and wet outside for me to be messing around with electrical outside. Plus he owes me a couple favors.

 

This is exactly what I was thinking.

 

After July or August of 88 there is no solenoid resistor in the circuit. Toyota switched to high impedence injectors 13.8 ohms and the solenoid resistor was no longer required. Your wiring harness should be direct from the ECU to the injectors. 22-RE's are still batch fired so No. 10 or No. 20 will both complete the ground circuit and fire the injectors, so if #1 annd #3 are consistently not firing then I would be checking the power wire splice that ties the two together. In the diagram it is the yellow wire, but your 91 probably is a different color.

 

It seems like i fixed my problem. I had injectors 1 and replaced...again. The harness is pristine. I got to the point of frustration where i started swinging a hammer at random parts of the intake manifold. I hit the cold start injector and the idle smoothed right up and the misfires seemingly stopped. I'm about to go take it for a test drive. But i have to say, things are looking good.

My best guess is that the CSI was stuck open with some crud or something and the knock with the hammer knocked it loose.

 

or you whacked the injector ground to work temporarily....my 89 looked perfect also...till i bent the wire and it broke in half,they corrode from the inside out,turn black and very brittle.

 

I have a late September '88 with the resistor.

 

So, swapped the CSI and it runs infinitely better when it's cold now. One it heats up I get the same old problems again. Out of shear nowhere I decided to tap on my fuel rail with a 6in extension and doing that clears the miss and the rough idle issues right up for about five minutes at idle. Now I'm back to being stumped.