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I also wonder if I never actually was at full throttle before due to the loose cable...
Symptoms which were remedied by this ONE ADJUSTMENT:
Harsh ("bang") shifts. 2-3 was often particularly bad under low and medium throttle. All shifts are now smooth and precise, better than they ever have been.
"Dokkan" rocket start is improved even further, 1st gear crawling performance is now incredible, the car no longer surges. It's such a change in stop & go traffic where the car is downshifting to 1st gear at 3mph.
On the highway in 5th gear, maintaining speed below 10% throttle now far more precise and deliberate. My car had started developing difficulty accomplishing this beyond the improvements that had been make with the Dokkan repair.
The differences are actually so significant, I'm having to re-learn how to drive the car.
I can actually achieve full throttle now. I used to shift ~5500rpm, now it shifts precisely at 6000.
p.s don't over-tighten the cable, it should not rotate the throttle. You're looking to remove slack, not create tension. I believe between 0-1mm is acceptable. I'm barely pushing down on the cable in my video and it is not taught what so ever. I believe I had to make about two rotations of the nuts to bring my cable into adjustment.
ppp.s I'm still staggered by this fix. It's something an idiot like myself can accomplish with a few hand tools, yet it makes such a remarkable difference ot the drivability of the car, but it's also something which can be easily overlooked by even professional mechanics (because everyone who has looked at this car has missed it).
pppp.s Here's another youtoober talking about this on his Integra:
There was a bunch of slack in my 1995 LS throttle cable, just tightened it up, need to keep driving but seems more eager and willing to kick down into a lower gear when I push it. Feels so much better. I had pretty smooth shifting before need to keep driving to see if there’s any improvement in smoothness but definitely a more responsive car now. Thanks for flagging this for everyone.
For those of us with 1997 or older the FSM describes how to calibrate the “other” cable ie one connected to the transmission, however I feel like with everything getting stretched out with age, I am not sure anything is better than trial and error on that one. There is a video on YouTube of a guy doing the adjustment on his first gen but I think he’s actually doing it contrary to the FSM by pulling off and disregarding the rubber stopper. He said it fixed all his problems though. Maybe I’m the one misreading the manual, or maybe for 89-94 it’s different. Attaching pages from 96 FSM and then further below is video.
So... I finally went full throttle. It turns out, until I tightened the throttle cable, I wasn't actually getting full throttle from my car.
For the entire time I've owned the car, I have never actually shifted at redline. I've always thought it was a bit strange the car ever so slightly short shifted at ~5700-5800. But now, after making this adjustment, I shift at 6000 or maybe even a little over.
Car doesn't really feel any faster. But now I know it's working properly
Last edited by 400fanboy; Jul 2, 2023 at 03:39 PM.
I've always wondered about slack in the throttle cable but never bothered to experiment with it. What I've never been able to get my head around is that the only interaction the cable has is with the pedal position sensor (1998 - ). If the cable still has slack after adjusting it, the pedal position sensor hasn't moved from it's position before the cable adjustment. None of the inputs have changed, yet there's a noticeable change in how the engine performs.
ECU controlled throttle plate opening:
Inputs:
Throttle pedal position sensor
Throttle position sensor
Other misc inputs (RPM, road speed, etc.)
Outputs:
Throttle control motor (opens and closes plate)
Transmission shift control
I also haven't been able to find a throttle cable adjustment procedure. I have a fear of losing whatever baseline the cable is currently set at if I start experimenting. 1998 LS400 FSM - Throttle Body Components
That's actually a interesting point. I kind of alluded to this in the first post. You're right, it shouldn't matter if there's slack... There is no sensor upstream of the adjustment point of the cable. The car should have no idea whether it's taught or slack, nor should it matter.
None of these items are sensors of any kind within the throttle linkage. Yet the differences in the physical performance of the engine are remarkable and without question substantial.
My only theory, when it comes to full throttle, is that the pedal when depressed on the floor, is insufficient to fully rotate the throttle assembly due to the extra unintended length of the cable. The cable is physically too long to allow the throttle to fully open.
However, this does not explain the remarkably sharper shifting performance. THAT is the true mystery.
Last edited by 400fanboy; Jul 2, 2023 at 07:32 PM.
Loose throttle pedal\cable
