No Start 89 SHO

[Platinum89SHO]

No-Start SHO

Having owned and driven this car for six years with the only previous no-start being caused by a small cat unplugging the main power to the fuel pump, the connector next to the radiator, while clawing its way into the engine compartment, and now the car is dead in the carport.

I pulled the KOEO codes and got:

15 Failure in Electronic Control Assembly (ECA) problems with Keep Alive
Memory.

And in Continuous Memory:

66 Mass Air Flow (MAF) sensor voltage too low.

I replaced the ECA with a factory refurbished one, leaving off the “SuperChip” that was plugged into the old unit.

Charged the batt and cleaned the terminals.

The SHO still would not start.

I pulled the KOEO codes again and got:

11 System Pass

Everything seems normal except the starting. The fuel pump turns on and then shuts off as normal, assuming it has reached pressure.

I pulled a plug wire and inserted a new spark plug into the boot, grounding it to the negative post. No spark.

Any suggestions on how to proceed?

 

[elarm1]

What is it doing while trying to start? Tach bouncing? Sounds ignition related to me.

 

[Off Road SHO]

Check to make sure that you did not inadvertently leave off a ground wire somewhere. Also make sure that the PCM, (the computer that is buried in the firewall above the glove box) that you changed out is getting 1: power and 2: ground. I don't have my EVTM's nearby but I think the PCM get's ignition switch power on pins 37 and 57. I can't remember which pin is the "always hot" pin (usually yellow in color and I think it's in position 1) on the PCM.

Also make sure that the little single wire connector behind the plenum crossover tube, is connected. That is the grounding wire for the Crank Position Sensor and is right next to but separate from the crank sensors main feed plug.

Tom

 

[Platinum89SHO]

"Tach bouncing? Sounds ignition related to me."

The tach moves to approx. 200 rpm then backs off a bit every time I hit the ignitiion switch. Is this the bounce? The starter works fine, BTW. Everything electric works as it always had. The check engine light only came on during starting and then would go off.

I checked (3) ground locations on the passenger side of the engine compartment, found one loose and tightened it. Still no start.

All wires appear to be plugged up properly. The only thing I disconnected is the battery ground terminal and the ECA (ECA = PCM?) main connector. I believe that connector was put back in properly.

Other than that, nothing has been touched since the last time it ran. There was no warning to this failure. It was running good when I parked it. Came back the next day and it won't crank.

I also grounded the lower screw of the DIS to the negative post and grounded an intake manifold bolt head to the negative post. Still no start.

 

[Off Road SHO]

Oh, so it won't even crank? That's a different scenario all together.

Tom

 

[Off Road SHO]

No-Start SHO

Having owned and driven this car for six years with the only previous no-start being caused by a small cat unplugging the main power to the fuel pump, the connector next to the radiator, while clawing its way into the engine compartment, and now the car is dead in the carport.

Any suggestions on how to proceed?

I believe the PCM gets its power from the CCRM near the radiator. Has that catclaw damage been repaired completely?

Tom

 

[Platinum89SHO]

Sorry, the starter motor turns the engine over fine, but no spark, so it doesn't start.

The catclaw problem was over a year ago and have had no problem since replugging and taping the connector together. The cat was a stray at another location and is not part of the existing problem.

Looking at an ECM pin diagram, I'm wondering if the ignition switch could be a problem?

I'm also reasoning that if the ECM were not getting power or ground, the code reader may not work(???)

 

[CademiaX]

cps possibly? If there is for sure no spark or fuel, that would be a likely cause.

 

[Off Road SHO]

Could be a switch problem. From the switch I think the power goes through the clutch safety interlock switch and then to the PCM.

Tom

 

[Platinum89SHO]

If it's a CPS, won't a code show up?

PCM = ECA? Or is the PCM a separate module from the main computer?

 

[1bad98SHO]

PCM is the main computer. PCM;ECM same thing

 

[shoclown]

if you need a no start sheet (step by step flow chart let me know pm me an email adress

 

[Platinum89SHO]

I had to put the SHO repair off while working on renovations to my home for the last two months.

Today I pulled the ECA (PCM, ECM) and inspected the pins, cleaned them and re-installed. Re-installed the "SuperChip". No start.

I pulled a plug wire and inserted a good spark plug and grounded it. Cranked the engine over with the key on. No spark.

Ran another KOEO with the code reader. Once again, had "11" in both memories (System Pass). Still no-start.

If I had a bad CPS (crank position sensor), wouldn't I have a code showing up?

Even with the old ECA, it didn't have a code for a bad CPS. The only code I got was a "15" = ECA bad keep alive memory.

Could I have gotten a bad remanufactured ECA?