No Start w/ Code 21

[Ocnaj]

The car is an '89. It will crank but the tach doesn't budge while cranking and it is throwing code 21. This would be the CPS right? Is there a way you can test the CPS?

 

[gurucomputers]

Code 21: Engine Coolant Temperature (ECT) out of self-test range

This does not sound related to your issue.

Sounds like Camshaft Pos. Sensor to me. They are cheap around 25-30 bucks and fairly easy to replace. I would start there.

 

[itwonder]

Sounds like the CPS. You can probe the wires at the round connector behind the DIS with a 12V LED (not incandescent) test light. The connector has 4 wires looking at plug with the largest tang towards the top. Pins 1 and 2 are on top, and 3 and 4 on bottom, like this: 1 2 4 3. pin 1 is pip to eec, Pin 2 is pip to dis , pin 3 is v-bat, pin 4 is ign. ground. Pin 3 should have +12 volts power, and both the pips will have an AC signal (varying voltage, flashes the LED light).

 

[Ocnaj]

Sounds like the CPS. You can probe the wires at the round connector behind the DIS with a 12V LED (not incandescent) test light. The connector has 4 wires looking at plug with the largest tang towards the top. Pins 1 and 2 are on top, and 3 and 4 on bottom, like this: 1 2 4 3. pin 1 is pip to eec, Pin 2 is pip to dis , pin 3 is v-bat, pin 4 is ign. ground. Pin 3 should have +12 volts power, and both the pips will have an AC signal (varying voltage, flashes the LED light).

Thanks for the info. What does pip stand for?

 

[gurucomputers]

Thanks for the info. What does pip stand for?

Profile Ignition Pickup

 

[Ocnaj]

I'll let you guys know what happens when I work on it 2morrow.

 

[projectSHO89]

A failed cam sensor will NOT cause a "hard" no start condition. You will still get a spark and a 1 in 3 chance that the injector timing will be correct for that attempt.

I once ran my 89 for several weeks with the CID sensor disconnected until I got around to replacing it.

A crank sensor, on the other hand, will leave the engine as dead as the proverbial doornail.

Steve

 

[Ocnaj]

The crank sensor is sending both pips. And I have 12 volts at pin 3. What is the single connector for? Is this another ground? Maybe the pip isn't making it all the way to the computer...

 

[projectSHO89]

PIP doesn't have to go to the computer, only the DIS module.

The single wire connector is either signal return or shield ground, don't remember which off the top of my head.

Steve

 

[Ocnaj]

Could the DIS be bad in this case?

 

[projectSHO89]

Perhaps. There are other things that should be checked before reaching that conclusion. That's the purpose of following a diagnostic procedure - to avoid guessing.

You have verified that the DIS is properly grounded to the intake, the intake cross-over tank is grounded, and that the grounding strap is properly connected, right?

Also, that the small ground wire from the battery to the chassis must be checked.

What is the history immediately prior to the failure?

Steve

 

[Ocnaj]

To tell you the truth I don't really know the history of the car. For all I know the owner prior to me might have screwed with the electrical system. But yeah all the grounds are good. I sanded the back of the DIS and the crossover yesterday too just to make sure it was grounded.

 

[Ocnaj]

I swapped a good DIS that I knew worked into the car and it does the same thing. Correct me if I am wrong but the tach should move a little bit while it cranks right?

 

[itwonder]

Suggest further diagnostics:

Connect either of the bottom DIS screws directly to battery ground. This rules out DIS grounding issue.

Probe Signals/voltages at DIS using LED probe:
Facing DIS so you can read the label on it:

• Left connector has pins 1-6, top to bottom
• Right connector has pins 12-7, top to bottom

Pin List

• (R/LG) VBAT
• (LB) CID (Cam Sensor) to DIS - Slow flash on led tester
• Not used
• (GY) CPS (Crank Sensor PIP) to DIS - Faster flash than CID
• (Y/LG) SPOUT signal, DIS to EEC
• (R/LB) Ignition Switch Feed, Reset
• (O/R) IGNDD, IGN. GND. to EEC - Connected internally to lower 2 mounting screws.
• (Y/BK) Coil A or Coil 1 signal
• (Y/W) Coil C or Coil 3 signal
• Not Used
• (Y/R) Coil B or Coil 2 signal
• (W/PK) or (GY/O) IDM ( EEC to DIS, tachometer)

The LED light should show activity on pins 2, 4, 5, 8, 9, 11, 12 when cranking.

The CPS has two PIP signal leads. Pin 3 on the round connector is the one that feeds DIS pin 4. If the tach is not moving, the other CPS PIP signal that goes to from the round connector (Pin 2) to the EEC (Pin 56) may be missing. Or the IDM signal between DIS (Pin 12) and EEC (Pin 4) may be missing. Along the way, the IDM signal passes through C126, a gray colored round connector located on the rear valve cover under the little vacuum reservoir.

 

[haydenkayne]

dude replace your crank sensor, if you tach dosent work than thats prob your best bet , may as well do a lower 60k while your at it

 

[Ocnaj]

Well, I checked over everything today again to make sure I wasn't missing anything and I found that the timing belt was rubbing against the crank sensor wires. So I swapped crank sensors and it fired right up!

The bad news is it knocks. From the information I can gather it hasn't ran since 2005 being there is a rejection slip from an inspection station in the car that was made only 20 miles ago according to the odometer.

It doesn't run the best but it idles fairly smooth for having a knock. Since the car hasn't ran in so long would it be safe to assume that the gas is that old too? Would the old gas affect its performance alot?

Thanks everyone for the help and bringing another SHO back to life, especially an '89.

 

[gurucomputers]

Well, I checked over everything today again to make sure I wasn't missing anything and I found that the timing belt was rubbing against the crank sensor wires. So I swapped crank sensors and it fired right up!

The bad news is it knocks. From the information I can gather it hasn't ran since 2005 being there is a rejection slip from an inspection station in the car that was made only 20 miles ago according to the odometer.

It doesn't run the best but it idles fairly smooth for having a knock. Since the car hasn't ran in so long would it be safe to assume that the gas is that old too? Would the old gas affect its performance alot?

Thanks everyone for the help and bringing another SHO back to life, especially an '89.

Find where the knock is comming from. Could be rod bearing. I bought a 91 this year that has been sitting since 2003 and it fired right up with the gas that was in it. The exhaust smelt a little funny and ran a little rough but there was no knocking from the motor.

 

[Ocnaj]

I'm almost positive it's a rod knock. I had it running on the 3 yr old gas. When I took it for a drive it didn't pull very hard. I was just wondering if the old gas would make it run like crap...

 

[itwonder]

I'm almost positive it's a rod knock. I had it running on the 3 yr old gas. When I took it for a drive it didn't pull very hard. I was just wondering if the old gas would make it run like crap...

Yes, definitely.

Any chance it was parked in 2005 because of the knock? Rod bearing job is not difficult on the SHO.

 

[Ocnaj]

Yes, definitely.

Any chance it was parked in 2005 because of the knock? Rod bearing job is not difficult on the SHO.

It might have been but I am not positive though. How should I go about draining the tank? Would it still run if the timing was off a tooth?