I HAVE A 1987 TRANS AM THAT CAME WITH A AUTO 700R4 TPI 305 WITH A DIGITAL DASH. THE ALL DIGITAL DASH WORKED PERFECTLY WHEN THE TPI 305 AND 700R4 WAS IN THE CAR. WHEN I DECIDED TO SWAP THE CARBED 383 BLOWER MOTOR AND TH350 TRANS OUT OF MY OTHER 1986 TRANS AM WITH A NORMAL GAUGE CLUSTER. (the 86ta was originally a carbed 305 700r4) (all gauges worked in the 86 cluster perfectly) THE DIGITAL DASH LIT UP BUT EVERYTHING ON IT GAVE CRAZY READINGS. THE BAR GAS GAUGE DOES NOT WORK, THE TACH IS PEGGED AND THE SPEEDO WHILE DRIVING AT ANY CONSTANT SPEED IS ALL OVER THE PLACE. (ex. if im going 35mph THE SPEEDO WILL GO FROM 67,123.101,40 etc. in a minutes time) NOW I DID NOT EXPECT THE DASH TO READ ANY OF THE CENSORS BECASUE IM NOT USEING ANY EXCEPT POWER, GROUND, TACH, AND SPEEDO WHICH IS HOOKED UP TO THE TRANSMISSION. WHAT I REALLY WANT IS FOR MY GAS GAUGE AND SPEEDO TO WORK CORRECTLY. I NO LONGER HAVE THE 86 TRANS AM DO TO A CRASH BUT I DO HAVE ITS ECM AND GAUGE CLUSTER. CAN THEY BE SWAPED OUT OR BETTER YET CAN I GET THIS DASH TO READ SOMETHING CORRECTLY? ANY SUGGESTIONS???

SOME SPECS OF THE CAR:

1987 TRANS AM
BULLET PROOF 383 STROKER MOTOR 508.8HP 512.4TQ

B/M 142 SUPERCHARGER WITH HOLLY VAC 750 CFM CARB

250HP NOS CHEATER SYSTEM WITH JACOBS ELECTRONICS NOS MASTERMIND

JACOBS HEI IGNITION

373 REAR WITH AUBURN POSI UNIT AND MOSER AXLES

TH350 TRANSMISSION WITH 700R4 TAIL (TRANSMISSION AND REAREND WAS IN THE 86TA AND SPEEDO AND TACH WORKED FINE)

 

hey man im gussing you took out the old computer , ther is a blacl wire and a black with yellow in the computer harbess that needs to be grounded

 

ACTUALLY THE COMPUTER IS STILL IN THE CAR. I DID NOT THINK I HAD TO TAKE IT OUT SINCE CAR STARTS FINE.

 

please discontinue use of the capslock key.

ok, i can't help you with your fuel guage, but as for the speedo:
i just swapped a WCT5 into my 88GTA that came with a 700r4 auto. the 700r4 had the correct Vss gears for a 3.27 gear ratio. the t5 does not. my speedo is 6% off, but it also jumps around a bit. somthing about these digital speedos, they don't like the wrong vss signal. if you take your car to a good speedo shope they can install the correct gears in the tranny (or somtimes install a converter inline in the wires) and fix the issue.