Over the past year, our 01 Sport has developed a rough idle (new plugs, twice) causing the check engine light to come on. Also, twice in the past month (both times within an hour of driving it 60 highway miles), it has started then died, then started put in gear and died. Started, put in neutral and it misses terribly; not wanting to run. After a minute or so in neutral, giving it increasingly more gas (too much gas and it will die) it starts cutting out less and less, then smooths out and decides to run fine from then on including the 60 mile highway run home.

For the past two years, when you put it in gear (either forward or reverse) and don't touch the accelerator, it slowly "surges" (even after replacing the plugs). When you give it any gas at all, it smooths out and runs fine. It's always run fine on the highway and gets 17-19 mpg.

Any ideas?
Thanks.

 

Check engine light came on - what trouble code did the PCM report?

 

As Salad mentioned. Check it for any codes, even you are not getting. A cel you may still have some stored codes. Checking for codes is always the best place to start since it will at least give you somewhere to start looking for your problem.

 

Agree with Salad and RTorrez1.....

The strategy for a check engine light is always the same. Get the codes and use that as your roadmap to troubleshoot the exact root cause.

Post the EXACT code number(s) here, not just a description. With OBD, the devil is definitely in the details.

 

I don't have a code reader, but the last time I had the shop turn it off, I believe they said it was a cylinder one misfire.

 

I have an 02 Taurus that sometimes does the exact same thing, mostly in the summer, and have had several people say it is probably the coil "thingy". Sorry, not even close to being a mechanic.

 

I believe the 01 has a coil pack... Have you checked the pack to see if it's still good?

 

Are you sure it wasn't a cylinder three misfire? My 2000 XJ would experience the same symptoms you describe after I shut it off, then tried to start again a few minutes later. I found out there was a service bulletin for the number three injector vapor locking after a hot soak. The fix was to install a heat shield around the injector. It turned out I had the heat shield installed, but it was sitting loosely on the injector. I installed two tie wraps around the heat shield to keep it snug around the injector. This made a HUGE improvement.

The last problem you describe may be related to a dirty throttle body. My XJ had a similar issue. I removed the throttle body and all the sensors. I gave the throttle body and all the sensors a thorough cleaning with throttle body cleaner and a soft brush. This eliminated the problem. I think it was mosty a dirty Idle Air Control Valve causing the problem.

 

How does one check to see if the coil pack is bad?
I did pour Sea Foam into the throttle body about a month ago and it smoothed out the idle. If that is the cause, what would cause it to "crud" up so quickly? It uses no oil, if that matters.

 

use an ohm meter on each coil and make sure they're up to spec

 

It's normal that things get crudded up after a while. In addition to cleaning the throttle body, I would also suggest pouring two bottles of Chevron Fuel System Cleaner into a full tank of gas. That stuff really works. (I've tried other cleaners and they did nothing.) I've heard people like that K2 stuff as well, but it's kind of expensive. You can often find the Chevron cleaner on sale at a parts store or you can get it at Walmart.

 

Thanks for all the replies. I'll clean the throttle body, install heat shield, and maybe check coil if I can figure out how to hook up an ohmmeter to it and what readings I should get.