2001 SS Jerking/Hitching at Highway Cruising

[01SsRacing]

Hey man any updates on the car?

[LangeZ28]

Shop could not find anything mechanically wrong. Going back to the tuner on Monday to do some data logging with EFI Live. Then analyzing it.

[01SsRacing]

Do you think its the locker just going in and out when off the gas because I dont feel it when on the gas feel it most when off the gas and hardly pushing on the gas.

[LangeZ28]

EFI Live on the laptop, should be able to tell me what the torque converter is doing, when the tuner and I are driving around data logging. I will be sure to ask about that on Monday.

[redss70396]

My 2002 with heads and cam and new trans build does the same thing. Trans guy says the aftermarket Vigilanty convertor is much tighter in overdrive than the stock one. I believe this to be true as before the trans build there was no jerking due to a faulty lock up clutch in the convertor ( Manf. warrantied ). Now that the lockup is working I have the jerking or lugging as if an 6 speed car in overdrive @ too low RPM. The problem goes away 60 to 65 mph. Maybe we need 4:10 gears as my tuner recommends.Does this happen if you do not shift to overdrive ?

[LangeZ28]

I have a 3200 Vigilante and have spoken with them many times. They deny that their converter is the problem. I even sent it in, and they took it apart and claimed nothing was wrong. I do agree that it feels like something with the converter but I cannot find the fault. It has been suggested to add 2 bottles of a friction additive like Lube Gard ATF Protectant with a fully synthetic fluid like Valvoline Max Life ATF. I tried it and while the trans seemed happier, the lugging continued.

I can detect the lugging in 2nd, 3rd, and 4th gears when cruising.

[SteveC]

There's probably room for improvement there. Most tuners who use HPtuners calibrate there MAFs with a histogram and a wide band O2 sensor. I'm not saying thats your problem...but the hitch/jerk/surge could be a tune issue in general, especially with big cams. If a tuner can datalog those surge events, hopefully he can tweak the timing and fuel tables in those specific areas to get rid of it.

I wonder if it could be the TC locking and unlocking during highway speeds?

SteveC

[redss70396]

There is some cam surge with a larger cam. Seems when my tuner takes the surge out at a given rpm the surge just moves up some on the rpm scale. I am positive none of this was happening before Vigilante replaced the faulty lockup clutch.When this convertor goes into lockup it has a huge drop in rpm.The factory convertor was much easier on rpm drop. Maybe the 10" convertor changes the overdrive ratio. It never was there with the stock components either. I will talk to my tuner this week to see what else he can do. One tuner tells me that this cam surge is caused by the MAF bouncing with the bigger cam. I doubt the owner of a new ZR 1 vette with same modes would live with this.Someone out there has the answer - let loose the tounge !!

[01SsRacing]

Well by the sound of it all our cars are different in the way with the about of add ons to them but yet we have the same feeling so whats the same on all the cars mine is 35K and almost all stock.

[redss70396]

I'm with you on the locker. Seems like there is a ton of slack in the rear end ? And when cruising at any speed car seems to have a feeling like the brake or something is grabbing causing the surge or jerking feeling. Man my 1970 Chevelle drives so smooth- why do these cars cause so much problems. There has to be someone out there who has the answer. We will gladly pay a Tuner to fix these headaches. Mike @ G Force - help out !!!

[01SsRacing]

I just feel like thats what it is. Idk about your car but I know mine if you have the windows up and you turn the music off and listen to the rear end you can hear it, and something that bothers me is when slowing down to a light or stop whatever you can just hear the rear end just knock knock knock it sounds BAD but everyone ive talked to say thats just how the rear end is, its how they always have been.

[redss70396]

I could not have said it better - decent engines , junk for transmission and rear end. Nothing like they built in the old days. The Chevelle still has the same 12 bolt rear end it was born with- with twice the HP and torque for the last 14 years and not one blip !

[01SsRacing]

Dont get me wrong I LOVE my car but your right things just arent made like they use to be and im only 20 years old and I even know this haha

[redss70396]

Next time you are out driving around run car to any speed and then place trans in neutral and coast. Very smooth and quite with no jerking.

[01SsRacing]

When I do that my check gauges lights comes on because my fuel gauge goes to E its weird idk why it does that so I try not to do that

[redss70396]

Does the engine die for a moment or something ? You telling me that you can't place car in neutral while going down the road ? If so then you have to find that problem and correct it. I know this is going to sound crazy but if you have ANY kind of issue with the transmission it can cause problems you can never find till you fix the trans. I know this to be true as I bought a Stage 2 trans off the internet ( big and costly mistake ) $1,895.00 - and the car would sometimes fall on it's face during hard acceleration as if it lost the fuel pump. The sometimes the guages woud do just as you say. It drove me crazy. I had another trans built by someone who knew what they were doing ( $2,700.00 ) and the problems all went away - just the issue with the crapy rear end.

[01SsRacing]

Does the engine die for a moment or something ? You telling me that you can't place car in neutral while going down the road ? If so then you have to find that problem and correct it. I know this is going to sound crazy but if you have ANY kind of issue with the transmission it can cause problems you can never find till you fix the trans. I know this to be true as I bought a Stage 2 trans off the internet ( big and costly mistake ) $1,895.00 - and the car would sometimes fall on it's face during hard acceleration as if it lost the fuel pump. The sometimes the guages woud do just as you say. It drove me crazy. I had another trans built by someone who knew what they were doing ( $2,700.00 ) and the problems all went away - just the issue with the crapy rear end.

NO the engine doesnt die when I put it into neutral, Nothing happens when I do it but the gauge thing I dont think I have a problem I just put it down to the sudden change trink the computer to thinking there is so fuel pressure.

[Cutlass]

thats not normal

[cammed goat]

Sounds like a momentary electrical cut-out when you shift to neutral. At least to me.

[Knight]

I wonder if there isn't some kind of short/ground with the neutral safety switch.