forcefed1

for some time now I have been trying to tune out what I thought to be a throttle tip in hesitation. when I go from no throttle to mid throttle in lower gears lower speed, I have a mild jearking. It feels like im absorbing driveline slop. I don't feel it as much when I let off though. just on tip in. I have come to the conclusion that it is not the tuning causing this feel.

what else could it be.
standing over the hood and shaking the engine by hand it hardly moves. I also was on the dyno recently and the motor didn't flex all too when under load.

what could be causing this harsh feeling. my car has 117K on it and as far as I know all the bushings are stock.

would this be rearend? would this be trailing arms in the rear?
toe link bushings?

Rx-7$4$me

Mine does teh same thing...

However my whole car starts to shake when im going in reverse or starting out from a stop sometimes and the RPMs dip to about 800 and the clutch is right at the friction point. And I dont mean that the motor shakes from being at too low an RPM, I mean the whole care shakes alot, it feels like minny wheel hop... any pointers for us?

Worn out bushings? I know my motor mounts are shot, and im hping once I get my torque brace from jason, it wont be as bad

Steve

maxpesce

forcefed - sounds like possibly sticky double throttle actuator - try disconesting the DTA (just pull and cap the vac hose) and drive it around for awhile, worn bushings/driveline componets usually make clunking noises.

RX-7$4$me - sounds like a worn Pressure Plate or clutch, or maybe the flywheel needs resurfaced, also could be a Differential problem.

NewbernD

iTrader: (1)

Yup.. I've got the same/similar thing. I end up on the clutch to make the transition smooth. I think my trouble is a worn diff. I can jack the rear up and turn a wheel a good bit before it catches and turns the other tire. Completely irritating.

Jack the car up and find the slop. It could be the diff bushing. Could be slop in the trans.. I doubt it's suspension related from what you've described.

forcefed1

I never thought about that one. Ill look into it this weekend. sure would be nice if it were easy like that.
as for the diff, I don't think that would be it as teh diff is pretty new.
If anyone else has any suggestions for us please speak up

spurvo

RX-7$4$me: how are your motor mounts? I replaced mine and went from a hopping front end when putting a load on the clutch in 1st gear (really bad going up a hill into the garage!) to nice and smooth....

forcefed: I've noticed this in both my FD and my FC when I had it. I think the throttle has three distinct positions when stock... closed, like decelerating the car, open as you accelerate, and this weird in between floaty position where you are neither accelerating nor decelerating. I can really hear it with the RB dual tips out the back. Anyway, I'm pretty sure this is an emissions thing to control the amount of throttle input during part throttle closed loop cruising. I think you just have to get used to it if you want to remain stock.

But I may be wrong...

Rx-7$4$me

oh my motor mounts are TOAST im sure, cuz I can move the motor very easily by just pushing on the UIM, once my feed torque brace gets in from Jason and JT imports, (should only be a few days) , im hoping that it will no longer happen, ruling out everything but my motor mounts.

911GT2

Torque braces are supposed to help this as rx-7$4$me said, I'll post back when I get my Garfinkle brace installed. I have the same issue right now.

Rx-7$4$me

Im pretty damn sure its my mounts.... as My WHOLE tranny is way over to the right when sitting on teh driver side. I had to take a crow bar and pry the entire thing over to install my short shifter. Now I can hear the trans vibrating against the frame right next to it, especially when I make hard left turns.

Rx-7$4$me

dont you have to remove teh ABS to install that troque brace?

crazzzzyy!!

Rx-7$4$me

911GT2

It depends. You can rent a drill from Home Depot or something like that, the drill just needs a 90 degree angle head. With the drill, you don't need to remove the ABS. Without the drill, you do need to remove the ABS.

I'm planning on renting the drill, because I don't wanna deal with bleeding the brakes. I'm going to HD on Monday. I'll post pics and a review when it's in.

The deal with the torque brace is this: Garfinkle sends you the two ends (one for fender side, one for motor mount) and you install and then measure the distance for the bar. He sends out the bar, and when you get it you send him back the installation tools, and the money. Sweet deal.

forcefed1

So did this help your tip in hesitation type problem or not?

I have had the car parked for nearly 3 weeks now waiting on parts and vacationing so I have not gotten to try out the double throttle bypass thing yet. ill post my findings

forcefed1

last night I took the car out and dissconnected the double throttle acuator vac line. I drove around for a bit and the car felt pretty much the same as far as teh rough throttle tip in.
it really feels like I have a bushing that is worn when i tip in. the hesitation bounces like it's elastic.
does anyone know what this could or would be?
I notice no cluncking like a bushing is warn out.
on another topic.... what exactly is the double throttle used for?

forcefed1

WELL

forcefed1

try again.
Im getting nowhere with this probelm.
last night lifted the car front and back and pryed on things with a bar to locate a warn bushing. nothing seemd to out of wack. the engine mounts were a bit spongy more than I thought they would be bit they didn't seem broken or anything.

the rear dif mounts looked pretty good also.

then I chacked my TPS sensor because I dug up some info suggesting I would get learching or hesitation on tip in if this were out of calibration.... nothing...

so Im at tha point here of trying again to describe my problem

let me start by saying I drove a friends stock car and his is smooth at throttle tip in. so there is something wrong with mine..

the probelm I have
driving down the road, say in 3rd gear at like 40mph. if I tip in the throttle I get this slight bucking and hesitationand it feels elastic like it's taking up driveline slop.... or bushing slop... and the engine is shaking. it shakes about 2-3 times and then nothing but smooth sailing. the whole thing takes less than 2 seconds to come and go. it feels as though once the load stabalizes everything is fine. at first I thought the problem was the enrichment settings with the PFC so I played with those for a few weeks and it got no better. just revving the engine parked. the engine seems fine. no missing or hesitation but that's with no load.

I did the test on teh double throttle as mentioned above and noticed no differance... at all.. car seemed to run the same with it connected or dissconnected.
is this normal? how does the car behave if the double throttle is not working correctly?

please someone point me in the right direction

PandazRx-7

iTrader: (18)

Any updates on this old thread?

I get that drivetrain shake when I'm at the friction point of the clutch going up a slope, I think it happens more when cold... Could it be my flywheel??

Also, I have a similar problem with jerking/driveline slop when on/off throttle...although it has been dramatically reduced from changing parts.

Recently changed/swapped parts:

Urethane motor mounts
Diff pumpkin (whole thing)
Diff bushings
Diff brace
Transmission

My flywheel is an 8.5lb aluminum that I bought 4 years ago...it was resurfaced when I had a clutch installed a year ago...and I can't see any cracks on the PPF.

Edit: Can this also be caused from the bearings in the axles??

93redFD

Bringing up this old dead thread, but Im having this problem too. I swapped diff from a parts car(the parts car didnt do this, so assuming the diff and mounts are good), I replace the drivers side engine mount with a poly-ur diff mount(works good, sends vibrations through the car, a nice solid feeling) The last time I looked the PP frame was ok. The only thing I can think of is the driveshaft, im thinking the U joints. Anyone found a "fix" for this?

Also, sometimes when im in reverse, going slightly uphill, it sounds like the driveshaft is hitting the power-plant frame(a ping noise). Any input would help. thnks

4CN Air

iTrader: (7)

I'm having these problems too, sometimes I get a loud clunk like my tranny has shifted over and hit the tunnel or something. Diff bushings are good.

PandazRx-7

iTrader: (18)

Sorry, I still have this problem, I've pretty much narrowed it down to either the PPF, driveshaft, or maybe even the flywheel...

93redFD

If your tranny is hitting the tunnel then its a bad engine mount. My last fd did this a little bit, so I know this has to be common problem.

93redFD

has anybody fix this problem yet????????