Rough idle, cold engine surge on start up.
10-03-2008, 05:26 PM
#1
JK Super Freak
Thread Starter
Rough idle, cold engine surge on start up.
OK guys here goes.
I was experiencing a slight rough idle especially when cold and also on a few occasions engine surge on cold start up. I've noticed I'm not alone and that its quite common on the JK's. After reading a post on the subject a few days ago I decided to try STP fuel injector cleaner as recommended by a member here. I have 6000 Kilometers on the clock so I had huge reservations that this would have any impact on my JK's condition. Well guess what not only did it help it was quite a drastic quick improvement. I haven't even gone through half a tank of fuel (fuel injector cleaner added) yet!
So heres the question. I only have 6000 Kilometers on the odometer. Why would the fuel injectors need cleaning already? I've had vehicles with 200,000 kilometers, no additives no fuel injector cleaning, and they idled and started fine. I know they needed cleaning because the FIC worked. Why so soon. I don't mind having to add injector cleaner every oil change but it just seems odd to me. Is this normal.
P.S.
What tipped me off is that one of our members removed his spark plugs to try and diagnose the same problem and posted a picture of the plugs. The plugs looked as though the vehicle was running rich. The OBC will allow the vehicle to run a little rich if the injectors are a Little fouled to compensate on fuel delivery.
I'm not going to go on and on but I welcome some opinions here. For anyone else with the same issue I used STP fuel injector cleaner, nothing special and it worked.
I was experiencing a slight rough idle especially when cold and also on a few occasions engine surge on cold start up. I've noticed I'm not alone and that its quite common on the JK's. After reading a post on the subject a few days ago I decided to try STP fuel injector cleaner as recommended by a member here. I have 6000 Kilometers on the clock so I had huge reservations that this would have any impact on my JK's condition. Well guess what not only did it help it was quite a drastic quick improvement. I haven't even gone through half a tank of fuel (fuel injector cleaner added) yet!
So heres the question. I only have 6000 Kilometers on the odometer. Why would the fuel injectors need cleaning already? I've had vehicles with 200,000 kilometers, no additives no fuel injector cleaning, and they idled and started fine. I know they needed cleaning because the FIC worked. Why so soon. I don't mind having to add injector cleaner every oil change but it just seems odd to me. Is this normal.
P.S.
What tipped me off is that one of our members removed his spark plugs to try and diagnose the same problem and posted a picture of the plugs. The plugs looked as though the vehicle was running rich. The OBC will allow the vehicle to run a little rich if the injectors are a Little fouled to compensate on fuel delivery.
I'm not going to go on and on but I welcome some opinions here. For anyone else with the same issue I used STP fuel injector cleaner, nothing special and it worked.
Last edited by cmpmacchia; 10-03-2008 at 07:54 PM.
10-04-2008, 06:16 AM
#3
JK Newbie
Join Date: Sep 2008
Location: Glenside,Pa
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Here are my thoughts, First I think the quality of gas is not as good as it was years ago. And second todays fuel injection systems are not as forgiving as older systems.
10-04-2008, 05:10 PM
#6
JK Super Freak
Thread Starter