So, I first noticed this when shifting. I would shift, and after I had let go of the clutch, it felt like it took a second for the drivetrain to completely engage.

While in second gear, I let go of the gas, and then gently push it. It takes about 2-3 seconds for the acceleration. It feels like something isn't engaging properly.

I have also noticed, when I let go of the gas and put the car in neutral, when coming to a light. The car will drop to about 500 RPM and then idle itself back to 750 RPM.

I am also noticing more backfiring when letting go of the gas pedal.

Any ideas? I replaced the clutch / flywheel about 20k ago. So, I am not sure if it would be the clutch going out, or what it could be.

Thanks for any help.

 

You may need a new clutch. At around 40MPH, put the car into 5th gear and then floor it. If you see the RPM of the engine jump before the car starts accellerating, then it's likely your clutch is going.

The idle fluctuation is due to your BAC valve. It is sticking or otherwise worn out. Try cleaning it with carb cleaner. If that doesn't work, replace it.

The backfire is somewhat normal with your mods.

 

Ok, thanks. I will give it a try on my way to work today.

I plan on doing emissions removal stuff, so I have BAC block off, just not in yet.

I also ordered a FPR. Hoping it helps with stuff. I really need to order a wideband O2. Was thinking about the UEGO. $150 i think for everything.

Thanks Aaron.

 

Alright, so I got on the highway and put the car in fifth gear and floored it. It just bogged a bunch and hardly accelerated. As i figured. No low end. .

But, it tells me it isn't the clutch.

When I installed the clutch, I remember putting all the bolts on at the same torque, but maybe a couple were off a little?

Also, for a while, I have heard a weird sound whenever I would take the car from neutral to first. I would put the clutch in, and then put it in first and I would hear a clunk sound. I didn't think anything about it. With the clutch in, the disc should be fully disengaged right? So the clunk couldn't be anything in the rear-end, but that is where I hear it from.

Also, with the clutch out, it sounds like the pilot bearing is rolling on the pressure plate. Is this possible with a hydraulic clutch? Do I need to adjust the clutch pedal? I will try and adjust it in a day or two. But it feels fine to me. Sound of the churning goes away when I put the clutch in. Pilot bearing was replaced when the clutch was. So, not too long ago.

Thanks for the info guys.

 

You will have the idle problem because you have removed you BAC valve. Put it back and all will be well again.

Bogging hard indicates another problem. When was the last time the car had a good tuneup? Is the TPS adjusted properly? It won't be a rocket ship in 5th at 40MPH, but it should not bog. The engine should smoothly pull the car forward.

Your new information leads me to believe that you may have a dragging pilot bearing, but that does not explain the original problem. It might also be that the throwout bearing is running dry on the input shaft snout, so it drags and thus the clutch may engage roughtly.

There is no adjustment for the cluch pedal that effects engagement.

Another thing to check are the hydraulics. Make sure the fluid is full, new and that the system is bled. Check for leaks at both cylinders, and cracks in the hose.

 

Something I did notice when I checked the fluid is that it is almost completely black.

I know it should be clear.... so, I don't know what would turn it black. It almost looks like oil from the engine that has been in too long.

I used DOT3 brake fluid, but cheapo stuff from autozone. I didn't think the clutch fluid had to be high performance.

The master cylinder is brand new. My old one I rebuilt and it went south. So, I just bought a new one.

Fluid stays at normal level, and doesn't drop. But the color is terrible.

Would adjusting the clutch pedal help the throwout bearing? Throwout bearing is what I meant originally. Long days.... so tired.

I figured removing the BAC is going to destroy my idle. I am alright with that. It seems to be going bad anyways.

I am sure I am due for a tune up. Maybe change the spark plugs and wires. I change oil every 3k religiously. New cap and rotor...... LoL.... J/K. Just had to replace it all on my GF car... cost me $120. . I am going to be parking my car for about a month to work on everything, so I am trying to figure out all the problems so I can work on them while everything is torn apart.

I am putting the S5 manifold in, putting Aux sleeves back in. With electronic control on both. I am going to send out my injectors to get cleaned by cruzinperformance. I am going to be removing the pulsation dampener, and banjo bolting it. Also doing throttle body mod, and emissions removal. And installing a FPR.

Then a few cosmetic things. I built a piece to put in right below my stereo, that has my cheapo A/F gauge, and 4 LED's...... eye candy.... . Red and Green.

Anyways. Let me know. I have to gut my GF's cat-converter because it is clogged, before I can drive hers. Then I can park my car. .

Thanks again.

 

If it has turned black, the inside of the hose is being eaten away. The blackness is the rubber from the hose and seals.

There is no clutch pedal adjustment past the freeplay adjustment.

 

Hmmm. Weird that the hose is being eaten. I bought my SS braided line from RX7.com . Hmmm, maybe I will have to buy another.

While driving around more today, something new is happening. At "barely touching the gas pedal", the car starts to surge.... little power... lack of power.... little power.... and so on.

I am going to get my GF's car fixed and hopefully when I pull the intake, etc. off, i can locate other problems.

Thanks again Aaron.

 

If you have new clutch line, then it's not being eaten (most likely). But CHANGE that black fluid.

The surging is caused by the TPS. Adjust it to factory specs.

 

I checked TPS. At normal operating temp it was reading 1.4k.

So, I adjusted it down to .95k. Throttle response is way better. The stuttering is gone. And most of the lagged engagement feels gone. I am thinking that maybe the car stuttering as I shifted is what made it feel lagged.

Still drops idle quick. But the BAC will be removed soon. Then at least I can get rid of all the ugly tubes.

What could cause the TPS to be so out of adjustment?

Thanks Aaron.

 

The TPSs and the lever pushing on them wear mechanically.

 

If I bought and installed a standalone, I could use whatever TPS I want right?

what TPS is best? Any that are more accurate then what is in either S4, S5, or any of the RX-7's? Nice aftermarket stuff?