I recently took my Ranger in for a it’s 60K service. It was running fine before I took it in, and the shop is one I have been going to for a long time. Some of the things they did was to flush the throttle body, changed the PVR valve, flushed the radiator etc (normal stuff).
After I got the truck back, the idle was really doing crazy stuff. It would rev up which I took my foot of the gas and pushed in the clutch.
I took it back immediately, and they ended up changing out the PVR valve to a factory one instead of the aftermarket one they had put in. This seemed to help a bit, but it still seems to be running strange. When I push in the clutch and take my foot of the gas the idle only drops to about 1400rpm (while I am still coasting). When I come to a full complete stop, then the idle will drop to about 800rpm. The guy at the shop said that it may be the battery since it was marginal when load tested (which I thought was a load of bull).
Before I take it back into them yet again I would like to find out what others think.
Thanks
Zack
when they feed you bull like the battery bit, then it’s time to switch shops. On the other hand yoj could regard it as a momentary slip by a puzzled technician and give them another chance…
I know, I agree with you about switching shops, but they have been very good over the years on other cars I have taken in :). I noticed I put in PVR and I should have said PVC in my original post… DOOH…
They probably changed the air filter. In doing so, they may have disconnected the electrical connector to the MAF in the large, black tube. They could have left a vacuum hose disconnected. Hopefully, they can examine their work areas around the engine and find out what they did. They may have another cow pie for you.
There may some truth to the battery comment. A few weeks back the battery in my 2000 Blazer was partially discharged when the interior lights were on for a few hours. The next day the truck took longer to start and the torque converter lock up was not engaging even though the engine was warm. The idle was 150 to 200 rpm higher than the normal 600 at a stop. The battery voltage was ~12.1 volts (25% charge). I used a Battery Tender to recharge the battery to 12.6 V, 100% charge. With the fully charged battery, the torque converter lock up is working and the idle has returned to 600 rpm. Check the voltage on your battery, if it’s low, try replacing or charging the battery with a trickle charger.
Ed B.
Sounds good. The car is over 6 years old so a new battery wouldn’t be out of the question.
I will try it this weekend. I also tried looking for a vacuum leak and didn’t find any. Tried spraying wd40 around the vacuum lines to see if it affected the idle speed and there wasnt any change so I don’t think it is a vacuum issue even though I was sure that was the problem at first 
Thanks for all the comments.
Zack