maybe hitting fuel cut?

[stockgp]

i went for a quick spin after replacing my hubs.  seems to run fine.  however, when i mash the throttle, the power cuts out.  not sure the rpm range as it was a short drive, but happens in every gear when i try to get on it.

new plugs and wires, old everything else.

also, how far off will the speedo be until i have kenny do my chip?  just owndering becuase i noticed that while my hud said 44 m/h, the gauge said 80 m/h

[grinders_18]

Curious...you asked how far off the speedo will be until Kenny does your chip. The chip doesn't operate the guages. The gauges go bad by themselves, and have to be resoldered at certain posts. A chip will not fix that.

I wish I could offer help on the power loss but I'm lost. BTW, HUD is typically dead on, even when the speedo is not.

[TGP Nick]

The gauge problem has nothing to do with your chip.. it is your cluster that needs to be recalibrated.

[grinders_18]

HA! In first...kiddin Nick...

[stockgp]

my understanding is that the 5 speed vss is incompatible with the tgp chip.  this is information i gleaned from somehwere on this site.  be it through pms or a thread, i don't recall

perhaps i'm misinformed?

[killinprixs]

about the boost cut... alot more important than your speedo issue.... How much boost are you running on your chip? Are you using stock wastegate solenoid?

[stockgp]

everything is stock except for the tranny

[killinprixs]

Check your wastegate lines...  If they are hooked up with no leaks or cracks, your car shouldnt hit boost cut.

[stockgp]

will do.  i'll let you know wha ti ifnd.  thanks

[TGPvsTIII]

the speedo will be off with a 5 speed in a tgp Kennys chip can make it accurate agian but it will not fix the differance between the heads up and the cluster. that would be what the others are saying to do.
Tim

[stockgp]

i don't care about the cluster.  i'll be swapping in a cutlass ub3 cluster and installing some aftermarket gauges.

i just want to know how far the hud will be off until i get the chip reprogrammed

[TGPilot]

Wow...I can not remember if the HUD and Speedo are different when the 5-speed is transplanted. I almost think that the VSS pulses are read differently between the analog gauge and the digital HUD. I do know that everything was dead on when I finally got the proper VSS and Pulse calculator right...oh wait Invasion was the one who finally got that right because I could not get the math right! There was one time that I had the math so far off that I went from 0-120MPH before I got the the end of my block...in second gear! :icon_redface:

Was your Speedo and HUD the same before the swap?

[stockgp]

i couldn't even tell you.

i only drove it once, in first gear, less than two miles.  that short jaunt was just to gauge the condition of the thing

[GutlessSupreme]

Our speed sensor is a hall effect sensor which sends electric pulses to the ECM. Voltage output changes with changes in the magnetic field around the sensor. The code in the ECM interprets the incoming voltage and outputs it as a data signal that (pretty sure) supplies both the HUD and cluster. There is a coefficient in the code that allows for calibration of the incoming voltage, to set which voltage = how fast the wheels are turning. 

The voltage from the speed sensor is affected by the tranny's FDR, the sensor ring on the differential, and our wheel/tire size. The coefficient must be used to account for these differences, in order for the ECM to calculate the speed properly and have a "normalized" output signal for the cluster/HUD. So where the stock ECM code takes into account our 245/50R16s and the final drive/etc. from the 4T60, the gearing and signal output from a Getrag 282 will be different and so the coefficient must be changed for the formula to give the right answer. This is why changing overall tire/wheel size from stock will result in the speedo being +/-, because most people don't reprogram/flash their ECMs whenever they change their dubs.

The HUD will likely always display the information from the data signal properly because of the way the circuit is set up. The cluster, however, requires a calibration resistor which limits the signal voltage to where the speedometer will accurately display the speed. Over time, the resistor degrades and the gauge will receive a higher voltage than intended by the ECM, thus the needle reads higher. The resistor is essentially the same thing as the ECM's coefficient, except it's a coefficient that changes over time. what a bitch.

Think of an analog voltmeter. In DC, you ground one wire and touch the powered wire with the other. The needle in the gauge will jump to point to the right voltage number. Now put MPH next to the numbers. That's the extent of it. All of our gauges are voltmeters with different numbers behind them.

So anyway. A different signal is coming from the transmission that with the auto, and a change must be made in the ECM code to account for it. It will work, it just has to be altered so the ECM knows what to expect. This will correct the HUD. If your cluster speedo is off, I don't think the ECM cannot accommodate for this. The speed will display differently than before, but it will still be exponentially off (faster you go = farther off it is). The cluster resistor will need to be replaced or another resistor added to correct the needle.

I'm 90% on the HUD/cluster shared signal thing, I don't have the diagrams in front of me but I'm pretty sure it all comes off the same DATA line with the rpm/fuel/etc information.

[mfewtrail]

I'm 90% on the HUD/cluster shared signal thing, I don't have the diagrams in front of me but I'm pretty sure it all comes off the same DATA line with the rpm/fuel/etc information.

The VSS signal output from the ECM gets split several ways when the wire enters the cluster. Pretty much everything in the cluster that takes a VSS input gets it's own part of the signal. That way if one component in the cluster fails, the rest remain operative.