Questions and Answers
Subaru Loses Juice Cold
Q. I have a 1987 GMC Caballero with a 4.3 liter engine. I have noticed when I let off the fuel sometimes it will want to pop back through the exhaust sometimes (as car is slowing to approximatly 40 to 25 mph). I am thinking maybe the EGR. Wanted your thoughts on this. The car seems to run great but just seems to do this once in a while. I did also notice when driving today it seemed to spark knock a couple of times until I "got down in it". A good deal of carbon seem to come out of exhaust and then it ran fine with no more problems. Does this not seem to indicate to you sticking EGR?
Thanks for any help you can give on this.
DonI, at first, thought it was a fuel problem, but it does not seem to be. I live in North Dakota so it gets pretty cold up here. The car will start just fine sitting in a 30 to 40 degree garage, or out side with block heater plugged in. I have also replaced ignition switch, coil, pickup coil in distributor and cap, spark plugs and wires, and there is a rotation counter under the dash that is tied in with this some how, I also replaced this.
I have been a heavy equipment mechanic for 20 years, and have always done my own auto work, I am out of ideas. Can you help please. (ne little thing I also checked spark with plug out and grounded, nothing there either.
Thank you,
AllenA. Since it is temperature related and you lose power, the first thing I would do is go over each and every connector and make sure they are clean and tight. I would also check all the grounds as well. Cold will break electrical contacts and many a problem has been fixed on Japanese cars by simply tightening a connection. As a matter of fact, a few years ago loosening and retightening ground connections was part of the pre-Delivery Inspection for most Japanese cars..
What I do is use a spare male terminal and check the female connectors for a nice tight fit. Also, just for giggles, replace fuse 12 - Ignition Coil (10 amp) and fuse 3 - ECU (10 amp) even though they may look good.
Additional Information provided courtesy of ALLDATA
