Road Trip Reveals a couple of faults...

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JoelR
Posts: 49
Joined: Sun Mar 09, 2014 4:19 am
Location: DFW (Plano) Texas

Road Trip Reveals a couple of faults...

Post by JoelR »

After a year of daily driving, I took the 6 (83 633 5-speed) on its first weekend road trip of about 350 miles round trip. On the trip down and on the way back there was a problem with the AC, and on the way back there was trouble with the idle.

It was sunny with the ambient temperature around 80 deg F, and the coolant temp was in the normal range. The AC was blowing ice cold as usual, until maybe an hour into the drive, when it just sort became mildly cool. After a while of this, I switched the AC off and on again with no change, so I let it sit off for about 15-20 minutes. When I switched it back on, it blew cold again for a while before warming back up.

The second problem occurred about 2 hours into the return trip when we hit a traffic jam in downtown Dallas. When I would come to a stop, the idle speed would dip down to almost 0 and then either recover or die. It stalled several times but started right back up no problem. After clearing the traffic and driving for another 30 minutes, it only acted up at two stoplights but did not stall again. Later driving that evening did not have any issues, nor did the commute this morning or evening.

Thanks in advance for any suggestions!

Joel
1983 633CSi 5-speed Black & Tan
2008 X5 4.8i
2004 MINI Cooper S 6-speed
2001 Z3 3.0i 5-speed
DFW Texas
euro24

Post by euro24 »

I don't know enough about the A/C to say, but sounds like a sensor or switch issue.

As for the second problem, it could really be anything causing it to act like that. Faulty connections or grounds, vacuum leaks, dirty ICV or injectors, faulty sensors (CPS, temp sensors, others) or relays (main or fuel pump, or others) that become intermittent when hot, tired fuel pumps, etc. etc.
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Brucey
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Post by Brucey »

re the AC; it could be a number of things but it might be as simple as it needing a regas; even a failing AC system can seem to blow cold in the morning, and will often likewise blow cold for a few seconds at least whenever you restart it.

Re the idle; the ICV ends up in a different part of its range when the engine is hot vs when it is cold. This can make the ICV slow to respond if the TB is set badly to start with.

So check the ICV isn't sticky at one end of its range, and reset the TB and then the TPS to factory spec as a matter of course; if they have not been done for a while they will need doing. Do not omit to reset the TB!

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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