CID and Computer?

[tommyturbo]

Hi All,
I got this 89 about 3 months ago. Since then this has been a constant battle. The car sets a code 19. I had the cam sensor replaced, but the code still comes up. I took it back to the shop I have been taking the car to, and they said they ran diagnostics and it was a bad ground, some pinched wiring and they fixed it.
The code came back up again just like it always does. I can only get about 2-3 miles after clearing the code and my check engine light is back on again with the same code.
The mechanic I used to go to said it could be a bad computer. Does anyone have experience with this same problem or can help? I'm getting really frustrated right now. I hate to keep throwing parts at something.

 

[shoclown]

there is a problem between your cid pip and idm. if you pm me a e-mail adress i can send you the diagnostic steps necessary to find problem.

 

[itwonder]

My guess is DIS. Make sure heat sink compound (Radio Shack has it), not grease, is used between DIS and the intake crossover. Run a temporary ground wire to either of the bottom DIS mounting screws to rule out ground issue. Also check the ground from the passenger side of the engine intake manifold brace to the firewall. Change out for known good DIS if you can get your hands on a loaner.

To diagnose the whole system, get yourself an LED type test light or Digital Multimeter. From an old post:

1. the Crankshaft Position Sensor CPS, Profile Ignition Pickup (PIP) signal to the DIS control Module (the box on the passenger side of the engine mounted on the crossover tube of the intake manifold.

Test #1 PIP to Control Unit:
Connect the test light by "back probing"* the dark blue wire at a connection between the two items (cps & control unit), and the negative battery terminal. The test light should blink as the engine is cranked, or a DMM (Digital Multimeter) should read between 3 to 7 volts.

If the PIP signal is OK - next test, if not the crank sensor, crank sensor power or ground, or wiring is faulty.

Test #2 if PIP is OK.
Spout to DIS Module (Spark Output of the ECU):
Connect DMM or LED to the Yellow wire with a light green stripe (Y/LG) and the negative battery cable. Crank the engine - LED light blinks, or DMM reads 3 to 7 volts.

If not control unit or wiring faulty. if OK, next test.

IDM(Ignition Diagnostic Moniter)to Control Unit.
Same deal connect DMM or LED to the gray wire with an orange stripe and the negative battery terminal, and crank the engine. Light blinks or the meter reads 3 to 7 volts.

If not - DIS module or wiring faulty. If OK next test.

CID (Cylinder Identification or camshaft position sensor)Use the LED test light at the sensor (DG) dark green wire and negative battery post, and (you guessed it) crank the enginre. The light should blink. If not the CID or the wiring is faulty. If test OK, next test.

Coil Power (PWR) Connect the test light between the coil power (VBAT)wire and the negative battery terminal, and put the key ON. The test light should be ON. If not, the coil PWR wiring is faulty.

"Back probing" is a process of sticking a probe in the back of a connection, or through the insulation, to make contact with the desired wire.