Hello All!
As the title states, I'm having a random misfire after changing out the following on my 1995 1fz-fe stock 80 with 252k on the clock:
Here's where it gets interesting. I buttoned everything back up and it was running smooth on initial startup for a few minutes with only one *slight* miss coming off 2k+ RPMs to idle. Almost like a little hiccup. Drove it home without any issues at 65-70MPH for almost 15 minutes, then the check engine light started flashing and engine started missing. (P0300, P0301-p0306) I limped home and here's where I'm stuck - sort of.
Items I've checked off:
Thanks!
Jeff
As the title states, I'm having a random misfire after changing out the following on my 1995 1fz-fe stock 80 with 252k on the clock:
- Valve Cover Gasket
- Spark Plug Seals
- Injector Service (all new o-rings/seals)
- Fuel Filter
- Fuel Pressure Regulator
- Vacuum Lines
- New cap/rotor/plugs/wires within the last 3-4 months - new plugs this past weekend
- Cleaned all upper intake passages and installed new gaskets
- Compression Test
- Valve Clearance Check
Here's where it gets interesting. I buttoned everything back up and it was running smooth on initial startup for a few minutes with only one *slight* miss coming off 2k+ RPMs to idle. Almost like a little hiccup. Drove it home without any issues at 65-70MPH for almost 15 minutes, then the check engine light started flashing and engine started missing. (P0300, P0301-p0306) I limped home and here's where I'm stuck - sort of.
Items I've checked off:
- Wire harness near EGR - nothing was "melted" but there were some cracks in the insulation so those have all been addressed and re-wrapped.
- No ECU issues with the wiring that I can see at the ECU and coming through the firewall. No grabbing/twisting/etc ever made a difference.
- Injector clips - there were several - especially #4 - that the wires at the clip had cracked insulation so those are now all new.
- Injectors - moving injectors had no effect. They all read in spec and are clicking during operation (used my stethoscope for confirmation)
- Plugs - moving plugs had no effect.
- All plug wires read correct impedance and cap/rotor look clean inside without any oil.
- New o2 sensors had no effect but the front sensor was covered in carbon.
- Cooling system has been effective - no overheating issues after replacing the fluid in blue fan clutch.
- After getting the 80 home, the battery kept draining quickly - I believe one of the injector clips was shorting and draining the battery immediately - that is no longer an issue.
- #4 intake tube AND upper intake near throttle body had a significant amount of standing oil/fuel mix which wasn't there after I cleaned it.
- Top of #4 cylinder was wet - this could've been due to what I think was a stuck injector/short.
- Upper intake was getting hot almost immediately during idle and misfire - which ties into the next test of the cat
- I removed the y-pipe and fired her up (sounded like a race car) and I was able to get it to idle smoothly after a few minutes. No bucking, no hesitation, no shuddering. I also heard a discernable "click" once when it was misfiring and it started running smoothly until I drove it down the street.
- Old test cat(gutted) was used after to make sure there wasn't a restriction, but the miss came back after a few minutes and short drive.
- When it was misfiring, I pulled #6 lead and could hear it arcing so I know spark is there, but the idle actually came up a bit and was running *slightly* better. Pulling other leads - #1 for example - increased the shuddering.
- Also NO smoke at startup - just rich fuel smell.
Thanks!
Jeff
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