A point of clarity please.
Both my vehicles have both.
I'm fairly clear on them, the how and and why they function. Not exactly clear yet on how they each evolved but I think it's safe to say that they've evolved to the point where most new engines are going to have both. The computer analysis data from both sensors to make its commands. Why aren't the MAF readings part of the analysis of the Vacuum Leak testing example you use? Are you just avoiding information overload in this lesson plan? Does One sensor have dominance over the other in terms of analysis or how the computer uses the information?
I've moved past here but still a little foggy with the relationship between the two?
Maybe I wasn't clear about my confusion...
MAP will idle higher
MAF will idle lower
What can I expect if both my vehicles have both when doing a vaccum test with propane?
Typically when looking for a vacuum leak with propane or another fuel source, you will be watching the oxygen sensor and fuel trim reaction. Regardless of the load sensor equipped, (MAF, MAP or both), the oxygen sensor will go rich and fuel trim will go negative when excess fuel is delivered through the leak.
Thanks for the reply Noah. Vacuum leak testing with in my case map gas is a great tool that I learned from the first few chapters.
Let's put my doubts to rest about my oxygen sensors. I have a Chevy Express van so the biggest problem I have with the gas testing is access. Even with the dog House off it's difficult to get to all the potential leak sites. A problem easily solved with a hose but even then without being able to see the area you can only get an idea of where a leak might be. Once all the ductwork is removed it's relatively easy but then that ductwork contains sensors also not the least of which the maf sensor.
Well everybody was blowing off fingers this weekend I stayed in and studied. My biggest problem so far is that I never have been one of those kind of people that can learn very much sitting down. I have to read something in a book 100 times and then tattoo it to the back of my hand so I can remember it if it comes out of a book but if I put my hands on a project and work through it a few times I'll have it forever. Paul of course tries to combine both and though it's slow going from me I feel like I'm gaining confidence with each passing day.
I'm almost to the point of having a real question for the repair section. No question is a stupid question but the wrong question can sure make you look stupid. It's bad enough to be stupid I just hate advertising it.. so I want to keep my questions on topic and not the kind I can easily look up myself.
Thanks again for your reply.
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