84 3.2 missing?

[VW_NUTT]

Hi all. I'm having a problem with my engine that has just started happening. The idle is fine around 8200. Its running like an old Chevy with a lumpy cam. car is shaking a bit. I was thinking it was a plugged injector so going by the Bentley I disconnected each injector one by one to see if there was a change is rpm. When I pulled #3 there was no change like the other 5 cylinders. So I figured it must be bad so to check it I swapped it with #1. Same symptoms. tried switching the spark plug with #1 same thing. Switched spark plug wire with #2,same thing. I also switched the injector wire from 2 to 3 still no fire. Spark is good. Next is a compression test tomorrow after work. Am I going in the right direction? could it be a bad valve? I checked the valve clearance it was a bit tight, but not enough to have the valve hanging open. Engine has 140K on it.

[schulr]

Mine does a similar thing but clears itself after the engine warms up. Believe my valve guides r showing some wear Is yours missing all the time? You might try some BK 44 and see if you can clean out the injector and be sure u r using the right gas like chevron that includes additives.

Bob

[VW_NUTT]

Always use premium. It just seems to be at idle. I know its not a plugged injector, I switched #1&3 around. #1 is fine after. Exhaust is very rich.

[scarceller]

Move the injector harness from 2 to 3 and 3 to 2, I think they should reach. You want to be sure it's not a wire harness issue on inj #3. The injectors in the 3.2L are batch fired, meaning they all fire at exactly the same time, all 6 are wired in parallel. No harm done if you swap harness wires around. Could be that inj harness #3 has a bad pin or wire, so moving it to cyl 2 will help identify and verify that the cyl #3 injector harness is good.

Also, if you have infrared temp gauge take a temp reading at cyl #3 exhaust port and compare to other cylinders at idle. If #3 is cold you know it's dead.

EDIT: I missed it, you already swapped the wires. In this case I'd still take a temp reading on Cyl #3 exhaust port. Also disconnect the IdleControlValve when doing the injector tests. Sometimes the ICV will compensate the idle very quickly and you won't notice the idle drop.

[scarceller]

The O2 sensor is on Drivers side bank so if Cyl #3 is dead then it's pumping air into the LHS heat exchanger and this extra air has tons of O2. This extra O2 is seen by the O2 sensor as a false lean condition because the O2 sensor simply looks for O2 content. Then the DME sees this as a lean condition and fixes it by enriching the the mixture and now you have the other 5 cylinders suddenly going rich. Bottom line is a dead cylinder in any O2 closed loop system causes over rich conditions in the remaining cylinders.

Originally Posted by VW_NUTT

Always use premium. It just seems to be at idle. I know its not a plugged injector, I switched #1&3 around. #1 is fine after. Exhaust is very rich.