91 ZR-1 Cutting Out Under Load

[XfireZ51]

"My scan tool showed the correct voltage readings, but I guess when the engine torqued just right it lost connection? "

If you had put the scan tool on and datalogged while driving, I'll bet you would have seen the MAP voltage drop under load.

[LT5-Lee]

Originally Posted by XfireZ51

"My scan tool showed the correct voltage readings, but I guess when the engine torqued just right it lost connection? "

If you had put the scan tool on and datalogged while driving, I'll bet you would have seen the MAP voltage drop under load.

I did, and it followed the throttle angle/voltage and engine RPM closely under load so I thought it looked fine, It idled at 750 RPM with 1.37v and at 0 rpm it read 4.84v EOKO. It did loose voltage about the time the secondaries should kick in so I figured that's about right (3300 rpm) with the drop in vacuum. Maybe I still have a grounding problem and just being fooled?

I still want to check all major grounds for grins and need some more practice and experience in diagnosing the sensors. Right now it sure looks like something is wrong with my o2 sensor.

Greg, all I am trying to say is did you hear it snap on, or did you just figure it has to be since it survived a death grip?

[XfireZ51]

Lee,

MAP sensor going to 0 v when opening
the throttle is the opposite of what should have been happening. That's the clue a scan can provide. It didn't last long enough to throw a code but it affected your throttle response