1995 Probe SE I4 2.0 5 speed
Over the last 2 months it has begun having the following problems:
Valve Chatter(most recent), rough idle, rough during heavy acceleration, difficult to start, especially when humid or after heavy rains.
Initially, it was just an occasional hiccup here or there, so I took my intake tubing out and tried to clean the throttle body with TB spray. When I put it all back together, it immediately became worse and worse to the point that it would take 10 minutes of trying to start it before it would finally sputter to life. When I am at speed and push in the clutch, it will lope from normal idle to about 1500. When I am at idle it will either idle okay then dip to about 500 come back or it will just cough at around 500 forcing me to tap the gas to keep it alive. This seems to be worse when the car is warm.
Previously, the only problems I experienced are severe oil leaks, throwing my alternator belt, one of my plug-wires(Cyl2) coming loose(thinking valve cover leak created pressure in the plug slide and pushed the wire up since I had the OE boots on the 8mm wires I cut and installed) and a strange issue where I take a sharp(ish) corner or turn over 20mph the car will try to bog out(not sure if lean or rich) if I keep the acceleration high and it takes a second or two for it to go back to normal almost as if something is shifting either restricting fuel flow or the spark is too weak(not sure if sharp turns can affect distributor spark). This last issue has increased slightly since I bought it nearly a year ago.
My buddy has a MX6 with the I4 and he has similar issues on humid days. We found that moisture in our distributor caps when they were having trouble. He changed his and it has been better. Mine was burnt out, the contacts were nearly nothing but carbon and the plastic was starting to be eaten up. I changed mine and the starting issue has eased, but it is running the same. I also increased the timing at the distributor in hopes of alleviating some of the idle issues, the result was minimal.
As far as any changes/modifications I've done, when I bought it I put an MSD coil and mapped my own CAI(no heat shield) to just below the battery. It ran fine for nearly 6 months. On the 95, there is a vacuum line that feeds to the air box, I did not incorporate that into the CAI. It has always had an exhaust leak, more so now that all I have is the head to the resonator.
Work I've done includes the aforementioned timing and cap. We've ran an OBD(no light on) and it showed two codes, one for the Cat but they were both old, I don't remember the other code. One of them is likely from when one of my wires came loose on Cyl 2 and it misfired. We've tested the TPS(within range), swapped the MAF with no change and even played with the air temp sensor.
We tested the resistance on the injectors, all within range. However, when the plugs for the injectors were pulled or the plugwires were pulled, we found Cyl 3 being disconnected reduced the rough idle to almost nil leading us to believe it is something with that Cyl. We tried a different plug wire which eased it slightly but nowhere near anything significant. We also ran a compression test on that cylinder with 3 cranks 3 times, all yielding more than 125 psi.
Currently, I am taking the engine out to replace all the seals and checks all the clearances, timing, etc and replacing the clutch.
Discussing it, we believe it to be one or more of the following issues:
Injector sticking(injectors look clean after I removed them)
Distributor issue(I don't see a way to change the rotor on this distributor)
Timing issue(I've had a serious oil leak in the valve cover and possibly the main seal leading me to think perhaps the oil has led to a jumped tooth, also considering a stretched belt)
Compression issue, I will be testing compression on all cylinders once the engine is out and on the ground.
Valves sticking open or closed slightly(possibly explanation for chatter if not worn shims)
However, with 3 seeming to be the culprit in all this, the timing belt and compression don't make since as I would assume a timing belt issue would create issues across at least 2 cylinders and Cyl3 tested good on compression.
So, anyone have any ideas? This is all the info I have on it. I'll keep this updated as I rebuild the motor and check everything out and when I get it back in the car.
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