tylerwerrin

Hi guys,

Recently I was having problems with my LT1 (95 camaro engine)throwing an intermittent DTC34 (MAP Voltage Low) when I had a high idle issue. I fixed the high idle issue, and the DTC went away. To ensure that it wasn't a gasket problem, I replaced the small orange rubber gasket that goes around the MAP. I also replaced the intake manifold gaskets to spec.

It's idling at a solid 850/900. However the other night on the way to the airport, my fans kicked on randomly. I thought it was an intermittent DTC11 (MALF light failure, which I had been experiencing) but when I got the light to register, the fans continued.

I scanned the computer when I got home and it showed that I had DTC34 again. What's more, when I'm in 2nd gear or 3rd gear holding a solid 2500-3000 rpm cruising around, I notice a slight stutter/sputter -- I don't know if it's related to the MAP, but I figure I could appeal to you guys for any suggestions. The TPS voltage is reading OK, if that makes any difference.

Does any one have any ideas on what it could be?

Injuneer

If the engine is above 700RPM, the code sets when the throttle angle is greater than 16%, and the PCM sees a reading of less than 16kPa for a period of 1 second. Generally, that represents a faulty sensor of a faulty sensor connector. There is no way, at steady state cruise conditions, and 26% throttle that the engine could pull the equivalent of more than 25"Hg vacuum.

The code also wouldn't indicate a gasket leak, because a gasket leak causes low vacuum, and the code is indicating unrealistically high vacuum.

Check the sensor connector. The plastic dries out and cracks, causing intermittent contact of the pins.

Fix the problem, and see if the stutter goes away.

tylerwerrin

UPDATE:

So i ran DataMaster to check the MAP reading -- it showed at idle (825rpm) I was pulling 32.5 kpa. My TPS voltage is a healthy .59. When i revved the engine to 1600, the MAP went up to 45.4, and the TPS% went to 18.0 and the TPS voltage was at 1.18 -- what was interesting is that in the time line, the RPMs actually went up HIGHER -- to 2275, ,and my readings were a TPS% of 0.0 and a TPS volt of .59 -- i attributed this to just the fuel that had just been injected into the engine a second previously (indeed this was but a few counts after I stepped on the gas.) Once the car returned to a normal idle, everything went back down to the way it was before.

I couldn't tell exactly when the DTC went on because I had tuned the DTC34 out so the fans wouldn't kick on -- what do you think this indicates? I can replace the MAP, but I have tried 2 seperate sensors and the code continues to return. I checked the torque on the intake bolts and they are all tightened to spec.

What does this mean?