Working on a 1981 olds delta 88 speedometer just

By wireing Im assuming you mean the wires for the fuel pump which is on top of the tank. the tank must be dropped to access them

YOU NEED BRAKE ROTORS FOR FRONT WHEEL DRIVE VECHICLE. THE 1987 OLDS DELTA 88 AND 1987 BUICK LESABRE FRONT WHEEL DRIVE SHOULD BE THE SAME.BUT GO TO AUTO PARTS STORES THEY CAN LOOK IT UP IF.BOTH HAD SAME TYPE FRONT WHEEL DRIVE SAME TRANSMISSION AND SAME WHEEL BASE AND DIAMTER EVERY THING SHOULD WORK OUT.

Check for spark at the coil and check for fuel getting to the motor. get back with me after these are done.

Yes you have to remove the spider gears,and the clip will come right out, it only take a 5/16 socket to remove the spider gears

check to see if crank sensor got damage

Unscrew the speedometer cable from the side of the transmisson. Pull the cable out of the transmisson. While someone else sits in the drivers seat and looks at the speedometer you turn the end of the cable quickly. If the speedometer doesn't move the cable is faulty. Replace it
To check the speedometer only disconnect the cable from the speedometer and insert a small screwdriver.Turn the screwdriver quickly. If the speedometer doesn't move then the speedometer is faulty and must be replaced.

HI. If your speedometer needle doesn't move, or if it flutters, your speedometer cable may be bad.

To determine if it is the cable, disconnect the cable casing from the transmission and from the back of the speedometer on the instrument panel. Draw the cable out from inside of the casing. The cable looks like a twisted piece or wire. If the cable is broken or if it is dry or brittle. It probably needs to be replaced. If the cable is intact and the same length as the cable casing, the problem is likely the speedometer head.

I would also advise to check the speedometer gear as well.

The speedometer gear is located on the output shaft. Inspect it for damage.

This gear rarely suffers damage because the gear from the speedometer that meshes with it is usually made of a softer material. Sometimes, the speedometer gear on the main-shaft is replaceable. A clip can hold it in place or it can be a pressed fit. A special puller is available to pull these gears on the car.

there are 2 or three fusible links in the main power cable i would check the ones from the starter

There are two possible things to check.The first being the ignition control module,and the other being the crankshaft position sensor.

you can get the schematic at autozone.com
online only