So...Anyone ever see this problem??

[supraguy@aol]

As the video explains, I get an engine miss, only when pushing the clutch pedal in about one inch.
It's not far enough to disengage the clutch, but maybe far enough to activate the clutch safety switch, perhaps?

The car is 7mgte, 560cc injectors, Lexus maf, intake and exhaust. No other engine mods.
Ignition was just verified at 10 degress btdc, brand new platinum plugs.
Please ask any other questions you might have.

 

[Nick M]

Does it have that very slight stumble at any other time, under any other condition of a load change?

 

[supraguy@aol]

Yes, if the engine was fully warmed up, and I gave wot, occasionally it would cut out on a cylinder.
Now, this WAS what it was doing, and I wasn't sure if it was an injector connection, or a spark plug wire grounding out.
I replaced plugs, cleaned the injector contacts, cleaned the igniter ground, and today I am picking up new NGK wires.
Since I did this work, the engine doesn't drop a cylinder at wot anymore.
However, it will stumble at idle- I.E.- it will drop from 700 rpm, to an occasional sputtering at 500rpm. Again, at full operating temp.
I tested the coils, they are at normal resistance, and I saw no cracks on the exteriors.

I will report back after changing plug wires(they look pretty old)

 

[Flateric]

It doesn't relate to your clutch symptom that I can figure but the odd engine sputtering and miss during different load changes may be explained by crispy CPS wiring.

My CPS plug back in my 7MGTE days had gotten very crispy over time and only after warming up it would lose connection on me completely and either stall or come real close to doing so when I was just creeping along only. School zone speeds, then the 7M would refuse to start for some time which baffled me completely until it cooled.

In the end it was my CPS plug that just acted differently during some thermal situations combined with specific engine load/vibrations. That CPS plug is in a very hot location under hood and yours is likely old and crispy and needing replacing even if it turns out to be not the issue here, but it's worth a shot. Your last post in this thread sounds exactly like the issue that changing the cps wiring solved for me.

 

[Nick M]

Yes, if the engine was fully warmed up, and I gave wot, occasionally it would cut out on a cylinder.
Now, this WAS what it was doing, and I wasn't sure if it was an injector connection, or a spark plug wire grounding out.

If the plug wire is not in its holder, it can rub on the throttle actuator pieces. The hard part with this if you don't have it an obvious problem is then getting a scope on the ignition and field current of the injector. Hard because most people don't own one. It doesn't take much to create a slight misfire. If they show ok, a vacuum test can be done followed by compression. And the variance will be smaller, as you have noticed. I am at 155k miles of intermittent hard driving, and I get 21 inches of warm vacuum. That can be used as a baseline.

 

[supraguy@aol]

Update:
Replaced plug wires, no change.

All plug wires are in the #3 valve cover wire holders. I will check the cps wires,
to see if there is any effect from messing with them.

 

[Flateric]

Did you ever get this resolved?

 

[supraguy@aol]

I tried reproducing the 2000rpm cutout the other day, but it wouldn't do it.
My stumble at idle was really bad though, I definitely had a cylinder missing. So I pulled over and checked the injector contacts.
Disconnecting and reconnecting #1 injector seemed to clear it mostly up, and the idle was back to 90% smooth. So I'm still not sure what was causing the weird cutout, but my idle problem in general, is tied to the injectors for sure.

 

[Flateric]

Hmm, or perhaps you bumped some other iffy wiring.

Time to take it step by step, perhaps change the injector plug, then swap the cps wiring or plug, sounds like an intermittent problem, my least favorite type.

 

[supraguy@aol]

Plugs on the CPS are brand new Toyota, and the issue only showed up when the injectors were swapped. The injector wiring is EV1/ Denso adapters, so no cutting or splicing was done.
The last 2 days have been largely sputter-free. I added injector cleaner to the fuel 3 days ago. Who knows...maybe I had a sticking injector.