3

(Solstice)

So, I cleaned my throttle body with brake cleaner. I thought it was carb cleaner, but I am apparently illiterate. (Honestly, I'm not sure what the difference between them is.) I was very careful not to get anything on the throttle control / sensor connector (one connector, electronic throttle).

When I put everything back together, I started the car, and it ran pretty well, though it was rough for a few seconds after starting.

No CEL, but I read the DTCs anyway and got:

0x7E8: P0107 - Manifold Absolute Pressure/BARO Sensor Low (Pending, Current)

(And the MAP reading in HP Tuners is flat, no variation whatsoever.)

Idled for about 5 minutes, revved the engine, and it stumbled and died. I pulled the codes and got a new one:

0x7E8: P0068 - MAP / MAF - Throttle Position Correlation (Pending, Current, Old)

Started the car again, stumbles and tries to die. Clear codes and, voila, it runs smooth again, but still has the MAP error. If I rev it up, it stumbles, dies, second code (MAF) comes back, and stays that way until I clear the codes.

Wash, rinse, repeat.

I'm a fan of consistent, predictable behavior but, sheesh - WTF?

Oh, and I looked at one of the logs from this morning before I cleaned the TB, and the MAP was working fine at the time. :( I wiped it down before plugging it back up, everything was dry. And now I'm stranded out of town until AutoZone can get a new sensor in tomorrow, for the low price of 100USD.

Pᴀᴜʟsᴛᴇʀ2
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3Dave
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1 Answers1

1

The problem was the harness.

On this car, there is a short "injector harness" which drives the injectors and the MAP, and is separable from the main engine harness. A solder joint near the MAP sensor connector was flexing and causing an intermittent signal path.

I had another injector harness with an incorrect MAP connector, so I cut the connector off of the first harness, Western Union-spliced it into the other harness, soldered and heat-shrink wrapped it. Everything is working fine now.

3Dave
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