DTC 23..........................MAT(IAT) low, it reads - 40 at all times, had a mail order tune, I don't know if this was programmed that way though
DTC 33..........................MAP high, 100.8, switched map, threw a low MAP code while cranking
DTC 36..........................High res failure, opti was replaced by a brand new one from Dal two months ago, since then the car has ran perfect without problem, this one surprised me.


Switched coil and ignition module, NO SPARK COMING FROM EITHER IGN MODULE/COIL COMBO


The car ran fine, no sign of trouble, then I left work and it just cranks, it started up and ran for about 30 seconds,idled fine,and then flat out died. My first impulse is to say it's the opti, but I don't know why it would die so quickly.

Any suggestions?

 

DTC 23 is a faulty sensor or the wire is off the connector. The sensor can be checked with an ohm meter. I have a table of temperature vs. resistance in my online Scanner writeup, it you need it.

DTC 33 can set if there is no vacuum, or if the sensor is faulty, or if the wiring/harness connector is not supplying the +5V reference signal. The connectors dry out and crumble, resulting in intermittent contact. Check the connector first.

DTC 36 may indicate a problem with corrosion on the harness connectors for the Opti. Check both of them. This will not prevent the car from starting. The PCM can default to the low res pulse.... you just lose a bit of timing accuracy.

 

The MAP is the only one out of those three that would cause the car to not start then correct? How would you suggest I check the connector?



the harness is new from when I converted to the vented opti 6 months ago, I used silicone grease to insulate it


Fred thanks for your help, I appreciate it greatly everytime.

 

Code 36 is pointing to thr optical sensor portion of the OPTI. I had a similiar problem with a "new" OPTI from a GM dealer. It went bad with less than 400 miles on it. I said to hell with it and put on the Delteq system. One of the best investments for these cars by far. Good luck, Rob. Check the connections again just to be on the safe side.

 

Since the Delteq needs a healthy optical sensor to feed ii, how did this work?

 

I replaced the optical sensor while I had it apart.

 

MAP connector seems fine, replaced with another map sensor and while cranking I get a low MAP DTC, dips down to the low 90s

NO SPARK AT COIL, switched the coil and ignition module with another one I had, no change, still no spark

The connector for the opti looked perfect

I have to start back at work tonight and this is my only transportation, should I go ahead and order another opti?

 

anyone have any suggestions as to why I'm getting no spark?

 

I find it odd that 2 of the 3 codes tells us that your signal from the MAP and IAT are high all the time. Meaning the signal from those devices is held above 4 volts and is not switching.

Both the IAT and the MAP share the same ground on the black connector at the PCM, pin 16 with the black wire. My guess would be either pin 16 or the wire from that pin has a problem or some of the ground points for the PCM are bad.

Pull the black connector at the PCM and check the last pin with the black wire. Then ohm it from the PCM connector to the IAT connector. If that's ok, check the grounds for the PCM on the head by the ICM and the other one above the starter. The grounds connect to the PCM on the Red connector pin 2 blk/wht wire and pin 18 tan/wht wire. White connector pin 32 blk/wht wire. Last, the blue connector pin 1 tan/wht wire.

Good luck
Dave

 

checking this afternoon..........



but regardless, shouldn't the motor try to start even with those not running correctly.

I'm not getting any spark at all.

 

got it apart, pulled out my multi meter and then realised I don't know how to check the circut, anyone want to offer some help?