1972 1.7 d jetronic runs great when hot. At startup, runs great at about 1500-1700. But when steps down about 2 minutes later, rough idle. Once warmed up, 10 min of driving, perfect idle of 800-900. Any advice?
Thanks,
Charpie
Full Version: Cold idle issue
QUOTE(Charpe197 @ Jun 20 2018, 10:31 PM) 
1972 1.7 d jetronic runs great when hot. At startup, runs great at about 1500-1700. But when steps down about 2 minutes later, rough idle. Once warmed up, 10 min of driving, perfect idle of 800-900. Any advice?
Thanks,
Charpie
My first thoughts are:
1. Your AAR is not operating properly - sounds like it's closing too quickly. In my experience they close more gradually - more like 5 minutes from total open to total close. I don't know how often this is a problem, though. Normally they just fail to open or close.
2. More likely, your mixture is just too lean during warm up. Could be your CHT is not functioning correctly (or maybe not correct CHT), or perhaps your fuel pressure is too low in general. Some people run Brad Mayeur's "spacer" that slows down the CHT warm-up, effectively giving you a richer mixture longer during the warm-up process.
More info on D-Jet: https://members.rennlist.com/pbanders/djetp...htm#Drivability
You can troubleshoot your CHT by checking resistance values between the lead and ground during the warm up process. There's more info in that link.
QUOTE(BeatNavy @ Jun 21 2018, 07:01 AM)
QUOTE(Charpe197 @ Jun 20 2018, 10:31 PM)
1972 1.7 d jetronic runs great when hot. At startup, runs great at about 1500-1700. But when steps down about 2 minutes later, rough idle. Once warmed up, 10 min of driving, perfect idle of 800-900. Any advice?
Thanks,
Charpie
My first thoughts are:
1. Your AAR is not operating properly - sounds like it's closing too quickly. In my experience they close more gradually - more like 5 minutes from total open to total close. I don't know how often this is a problem, though. Normally they just fail to open or close.
2. More likely, your mixture is just too lean during warm up. Could be your CHT is not functioning correctly (or maybe not correct CHT), or perhaps your fuel pressure is too low in general. Some people run Brad Mayeur's "spacer" that slows down the CHT warm-up, effectively giving you a richer mixture longer during the warm-up process.
More info on D-Jet: https://members.rennlist.com/pbanders/djetp...htm#Drivability
You can troubleshoot your CHT by checking resistance values between the lead and ground during the warm up process. There's more info in that link.
Where do you buy the spacer?
http://914ltd.com/store.php?c=1384303079
The CHT extension. May help, but make sure you read up on DJet too.
The CHT extension. May help, but make sure you read up on DJet too.
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