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Tim's Auto Repair
Tim's Auto Repair, mechanic
Category: Chevy
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Experience:  Have owned a repair shop for 25 yrs.
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1989 Chevrolet: K2500..TBI injectors are not cycling, what

Resolved Question:

1989 Chevrolet K2500 Truck Dead, TBI injectors are not cycling, what could be a control that is not working?
Submitted: 5 years ago.
Category: Chevy
Expert:  Tim's Auto Repair replied 5 years ago.

hi

first,you may want to replace the ignition module again,,,,,but,i would think your problem is the pick-up coil inside the distributer,,,the reason you don't get an injector pulse is because the computer doesn't know the engine is turning,,,,if the pick-up is bad,you may consider replacing the complete distributer sense the distributer will need to come apart to replace it

thanks

 

Typical Distributor Components

Customer: replied 5 years ago.
should there be voltage going back to the ECM from the Ignition Module? I still have spark.
Expert:  Tim's Auto Repair replied 5 years ago.

yes,,you can have a spark and still not have a injector pulse sometimes.......i would lean toward the pick-up on this one,,but,,if the module is new,and if you can return it,try this first because it is easy and is a possibility

thanks

 

Distributor Operation

 

Typical Distributor Components

Purpose:
The distributor distributes high voltage to the spark plugs to ignite the compressed air fuel mixture in the cylinders.

Operation:
The distributor has a separate coil which connects to the rotor through a high tension wire.

The distributor uses a magnetic pick-up assembly located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage of 35,000 volts is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. The capacitor in the distributor is for radio noise suppression.

This distributor also features a longer spark duration, made possible by the higher amount of energy that is stored in the coil. This is desirable for firing leaner mixtures.

Location:
The distributor is located in the top rear of engine.

Distributor Reference Signal

PURPOSE
The distributor reference signal provides the control module with both engine RPM and crankshaft position information. This enables the control module to operate the fuel pump relay and energize the fuel injector.

OPERATION
When the engine is cranking or running the control module receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the control module will not operate the injector.

Testing and Inspection

 

Fig. 4 Pickup coil test connections

 

Note Make sure the ignition switch is "OFF".
  1. Remove distributor cap.
  2. Disconnect pickup coil connector from IC module.
  3. Connect ohmmeter as shown in step 1, and flex pickup coil leads while observing meter. Meter should indicate infinite resistance at all times. If not, pickup coil is defective.
  4. Connect ohmmeter as shown in step 2, and flex pickup coil leads while observing meter. Meter reading should remain constant between 500 and 1500 ohms. If not, replace pickup coil.
Note To replace the coil, remove the distributor.

ignition module

Description and Operation

PURPOSE
The distributor reference signal provides the control module with both engine RPM and crankshaft position information. This enables the control module to operate the fuel pump relay and energize the fuel injector.

OPERATION
When the engine is cranking or running the control module receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the control module will not operate the injector.

Tim's Auto Repair and 5 other Chevy Specialists are ready to help you
Customer: replied 5 years ago.
Thank you, XXXXX XXXXX I am going to opt for a new distributor. With all the other new parts installed what the heck! Going to be my daughters birthday present at 16 in 6 months want it to be dependable. Again Thank You, Rafe
Expert:  Tim's Auto Repair replied 5 years ago.

thanks Rafe

yes,a rebuilt unit will be just as cheap as the pick-up sense it will take more work..

tell your daughter happy birthday and god bless..

thanks for using just answer