Mysterious miss and hesitation

[NCSHOracer]

In my 93 MTX with a rebuilt 3.0 we have got about 2500 miles on it where it ran beautifully and with no problems. But not long ago it developed a miss while cruising on the highway that has gotten worse. The car STARTS and IDLES with absolutely no problems and triggers no CEL's. When you get it on the road and strat getting it hot about 15 minutes later it will start to miss slightly and hesitate, when this happens it runs rich and backfires and pops and wants to die. BEFORE the popping occurs the CEL will flash and cut off and you can hear the airbox make sucking noises like it is clogged. Then the bucking of the car occurs and wants to die and stall. The following has been replaced:
- Both O2 sensors
-Cam
-CPS
-TPS
I have checked the codes and the ONLY code to pop up is 519 which is for the power steering pump switch. Will the power steering pump switch cause all of these problems or do I have another problem?
Thanks for reading!

 

[rubydist]

The check engine light will not come on for the 519 code, so if you really don't have any stored codes other than that, the pcm is highly suspect.

Your other candidates are crank sensor, cam sensor, dis, iat, etc. And yes, I know you just replaced some of those but infant failures do occur, so the fact that they may be new does not mean they are good.

 

[NCSHOracer]

I narrowed down DIS, I took it off and put it on another one of my SHOs and it ran perfectly. The CCRM is tested and works flawlessly on another SHO. I don't disagree with what you say about the sensors failing but I seriously doubt the cam or crank sensors are bad. I can swap computers and check those out when I have the chance and get back to you but any possible causes that you believe please list them as I want this car back on the road and racing again.

 

[Toolman]

Have you noticed the tach during this episode? Try running again to see if it replicates and observe the tach, see if it's running lower RPM than you think it should.

 

[NCSHOracer]

Have you noticed the tach during this episode? Try running again to see if it replicates and observe the tach, see if it's running lower RPM than you think it should.

The tach will speed up to 5k when it is actually 3k and then will drop but still running.

 

[rubydist]

then your cam sensor is highly suspect, whether new or not.