I have a 1990 pickup 2wd with 22RE and 4-spd automatic. I'm having an intermident problem with detonation (spark knocking). Could this be a faulty detonation sensor? This problem occurs on warmer days especially when running the air conditioner after driving for about 20 to 30 minutes. I've had this vehicle for three years now and it now has 144000 miles on it. When I got it I found out that the previous owner had appearantly skipped on doing maintenance. There was a lot of sludge in engine. I treated engine a couple of times with Z-Max (that got rid of a lot of the sludge) and last year I went to Mobile 1 high mileage sythetic oil. I also dropped the heat range of the plugs down 1 range (from 5 to 6). Does anyone else have any suggestions who may have seen this issue before?
when did you drop the heat range? Heat range was set there to burn it at the most optimal point when the engine was designed. Lowering spark heat range would've possibly left carbon buildup in the chambers or such. I think that could've started it. But for now, lets Use some Techron Fuel system cleaner, it's great. put that in the gas tank, and see how it goes, hopefully will clear up the injectors some. Idk, just look around for some obvious signs. Look at your connectors, grounds, wires, all of that. Regular gas or some E85!? lol good luck fellow 22re xcab auto driver
If you are running regular 87 octane gas, try filling up with Super instead. The Higher the octane rating the less likely you will have spark knock. Using super should completly get rid of all the knock.
I've been running 89 octane in the truck since I've had it. I thought about using the Techron and letting some of it getiing sucked in to the intake manifold via the vacuum booster hose port. I've been tempted to pull the whole top end down (head intake and throttle body) and decarbonize it. When the vehicle is cool (during cold weather or driving just a few minutes) it runs fine. It is usally when the fan clutch is working on a hot day such as today (95 degrees at over 90% humity) here in Charleston, SC is when it acts up. Does anyone have experience with the detonation sensor? Another thing I plan on doing is to change the fan over to an electric unit. The best one I've found is a unit from LC Engineering. If I can correct this issue, this truck looks and runs like new!
Try backing off the timing a bit and go back to the specified plug heat range... There's is also no detonation sensor, there is a knock sensor but, not on all 22re's...
