EVAP purge operation and PCM compensation
05-13-2005, 02:18 PM
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EVAP purge operation and PCM compensation Does anyone know how the PCM compensates for this? I have a suspicion that I am having some type of problem related to this.
Also, what does the PID for the EVAP operation really report? It seems to be listed as a %duty cycle. Is it a slice in time (100% or 0)?
The purge goes straight into the intake manifold so what is in place to account for this unmetered air.
The problem I’m seeing only seems to occur in the following situation.
- car is fully warmed up
- car is just started
- speed goes up to 5-10mph and then clutch is immediately engaged and car is coasting
It stumbles and almost dies then it idles normally. I have a log of the problem and you can see a rise in MAP with no change in the MAF readings. It got me thinking that something is suddenly letting unmetered air in.
Also, what does the PID for the EVAP operation really report? It seems to be listed as a %duty cycle. Is it a slice in time (100% or 0)?
The purge goes straight into the intake manifold so what is in place to account for this unmetered air.
The problem I’m seeing only seems to occur in the following situation.
- car is fully warmed up
- car is just started
- speed goes up to 5-10mph and then clutch is immediately engaged and car is coasting
It stumbles and almost dies then it idles normally. I have a log of the problem and you can see a rise in MAP with no change in the MAF readings. It got me thinking that something is suddenly letting unmetered air in.
