Just as I thought I had the surging idle problem fixed, it returned and reminded me of another nemesis that I had to battle to get the mustang running as it should….
I have been driving the car for a while now and thought I had the surging idle problem fixed. I was going to and from work with it and it was keeping a steady idle. But one day on my way home, I came to the last stop light before I get home (you know the type where you have to wait thru about 3 green lights before you get thru) and while waiting for my turn to go thru, the idle started going up to about 1200 rpm and then down to about 250… It kept doing this for a little while and then it did the inevitable… It stalled.
Oh great, it’s back and this time it is even worse than it was originally. Originally it would surge about a 3-500 rpm range; this time it was about 1000 rpm swing. This couldn’t be good could it?
Well top everything off; this was bowling league night, so I didn’t have time to really check anything out on the car. When something like this happens, I usually like to try to figure out what is wrong with it, at least identify the problem if not fix it. The thing to keep in mind is that the fixing it part is what sometimes takes quite some time. After all, you have to identify which parts are malfunctioning and then how you are going to get them. This doesn’t include replacing them. That can sometimes take days.
It is time again to revisit the surging idle checklist. This time I decided to do something I was avoiding. To be honest, it should have been one of the first things I did. Clean the throttle body. This is the little metal flap that allows air into the intake. It is something that is really inexpensive, and for the most part doesn’t cost anything since most of us that are working on the engine of a car already have a can of carb cleaner on the shelf. I figured I had about an hour, why not try to take the tubing off and clean that throttle body? I did this, and it did appear to be dirty.
Apparently it was much dirtier than I had thought. Once I had this cleaned and put back together, the car started and there wasn’t a surging idle. Well, that really isn’t much of a test as this seemed to have a surging idle once it got warmed up. So I have to start driving the car to work and see how it performs over the next week… (Go ahead, twist my arm and make me drive the mustang… ) Over the next week or so I drove the car back and forth to work with no more surging idle problems.
Do I dare say that the mustang is fixed? I have been burned on that one before. Well, remember when I said that this problem reminded me of another nemesis that I had to battle? Yeah, in driving over the week, I found that I need more practice driving a manual transmission. On occasion, I would stall the car when trying to start out in first gear. The dreaded slow start returned.
I will cover the cause of that one in my next blog post…