i put a 90 tpi in my 89 rs. i replaced the dash wires with the 90 one and the spedo was electric so used the old cluster and re wired everything. now would the senser give a differant signal to the ecm than the 90 digital sensor

 

In the '89 cable driven speedo system, the optically driven (from the cable) VSS buffer at the rear of the cluster sends a VSS signal to the ECM & the cruise control, which I believe is a 2000 pulse per mile signal. With the '90 ECM setup, the VSS buffer is built into the ECM & requires an VSS mounted in the transmission. In the '90 system, the ECM drives the speedo in the cluster with a 4000 pulse pe mile signal, and the cruise with a 2000 pulse per mile signal, so you will probably have to replace the cable driven speedo in your '89 cluster with an electronic speedo - either after market, or (this would be more difficult) try to transplant the electronic driven movement from a '90 speedo in your '89 cluster & redo the numbering. Another option would be to try & use a '90 - '92 cluster in your '89, but the form factors are different.

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Tim

1992 Z28, 305 TPI 5 speed, 12.0 sec @ 114.8 mph

1984 Berlinetta 305 TPI Auto, 13.8 sec @ 99.7 mph

 

well i will see what i can find at the junkyard this weekend.

thanks for the advice

 

will it cause the car to run rong if i dont hook it up

 

Your TC won't lock up (if you have an auto) and your purge solonoid won't work properly resulting in a fuel smell on shutoff. Car'll run fine, but altogether losing about 3mpg and increasing average heat levels in the tranny. Not that big a deal when you're just trying to work out the bugs from your swap, eh?

 

yeah the 89 has a t5 which is nice. i have been driving it and never smelled a gas smell but when i turn the car off the pump runs for a sec and then turns off. is that ok.

 

yea the pump will run for 2 or 3 seconds after you shut the car off.

 

is there any way to put together all the parts i need to get the vss up and running without having to do any major mods. the tranny i have is a t5 but the engine and harness came out of an auto.