so here's where my story starts I bought a 86 lx wouldn't start without some help sat outside for a year strut towers rusted out over the winter then bought a 92 4cyl roller with 50k miles on it sat in a barn for a while. I swapped the 86 engine into the 92 body and removed all the 4cyl stuff with a 92 engine harness and computer. Back to when I first bought it and had it running it had a bad misfire all the time while driving the owner said he replace the distributor and spark plugs. I checked timing and it wasn't adjusted properly I fixed it but the misfires were still there but less frequently when driving. Next I replaced the spark plug wires because they looked like they seen better days still nothing I checked the firing order and seen 6 and 5 were switched on some charts seemed better but now it backfires after 3000rpms more often. I just thought of something today since it is a 92 computer will I have to set up the plug wires the same way as a 92 engine or not because im thinking of the fuel injectors are probably going off a 92 engine not a 86. But I don't know where my problem could be I would like if I can get some pointers on where to look I want to finish this car before I go back to work whenever the virus ends.
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misfiring mystery
- Thread starter jesse997
- Start date
broncojunkie
Well-Known Member
The cam determines firing order. If it's a h.o. engine with stock cam, it's 1-3-7-2-6-5-4-8. Most aftermarket cams will be the same. Rotation of distributor rotor is counterclockwise.
I've been trying to find a stubborn misfire in one lately, so I can give you some ideas. There are a ton of possibilities, so this might point you in the right direction.
You can use your timing light to watch the spark signal on each plug wire. A better option is a spark plug test light.
Obviously, a misfire in a particular cylinder or two is much easier to diagnose than a random misfire. If you suspect a particular cylinder, you should be able to find it by looking at the plugs.
Are you using the distributor from the 86? I'm not 100% sure but the tfi module for 86 might be different for 92. The 92 ecm probably won't work correctly.
Throttle position sensor, dirty throttle body, dirty maf sensor, bad pickup in distributor, bad tfi module, bad fuel pressure regulator, dirty fuel filter (or strainer sock on the fuel pickup tube inside the tank), coolant temperature sensor, o2 sensor, burnt capacitors inside ecm are all common problems that can cause a misfire.
I've been trying to find a stubborn misfire in one lately, so I can give you some ideas. There are a ton of possibilities, so this might point you in the right direction.
You can use your timing light to watch the spark signal on each plug wire. A better option is a spark plug test light.
Obviously, a misfire in a particular cylinder or two is much easier to diagnose than a random misfire. If you suspect a particular cylinder, you should be able to find it by looking at the plugs.
Are you using the distributor from the 86? I'm not 100% sure but the tfi module for 86 might be different for 92. The 92 ecm probably won't work correctly.
Throttle position sensor, dirty throttle body, dirty maf sensor, bad pickup in distributor, bad tfi module, bad fuel pressure regulator, dirty fuel filter (or strainer sock on the fuel pickup tube inside the tank), coolant temperature sensor, o2 sensor, burnt capacitors inside ecm are all common problems that can cause a misfire.