- This topic has 8 replies, 5 voices, and was last updated 11 years, 11 months ago by
.
-
Topic
-
The wife’s ’99 Pontiac Sunfire has a rough idle and accellerates roughly after the engine heats up. It’s only got 32K miles on it and is RARELY driven in less-than-ideal weather. I’m just starting to troubleshoot this and I’m looking for some advice. I read that a bad tank of gas (or old gas in this case) might be something to look into. Someone suggested STP gas treatment but I wouldn’t know which of their products might be effective…if at all. Any suggestions? My next step should be to read the error codes. Gonna take it one step at a time.
-
Replies
-
have u checked the sensor like the idle control valve? or even the maf sensors? spark pl ugs wires etc?
I’m starting the troubleshooting process now. Just looking for the obvious at this time as it was running perfectly up till now. As a bit of history, I had to replace the alternator earlier this summer but the car has not been driven much since then. So far, I’ve taken out the spark plugs and cleaned and gapped them…but I know…just because I cleaned and gapped them doesn’t mean there’s not a sick one still in the group. I was looking for a quick something to try before I start swapping out parts. As I mentioned earlier, someone recommended dumping in some STP gas treatment but I have no experience with that stuff. I was hoping someone would give me a thumbs-up or thumbs-down on trying that and maybe even some caveates that might go with using something like that. Any thoughts? thanks again
I would start by getting the codes pulled. Most autoparts stores will do this for free. It’s odd that you would have to change an alternator after only having 32,000 on the engine. I’m guessing age had more to do with it then use. It could be bad gas, but as far as I know nothing can un-fowl gas. So you may want to syphon out the old gas. Maybe a bad fuel filter, try checking fuel pressure. It could also be bad oil. oil absorbs moisture from the air and start to break down even if it only has a couple hundred miles on it. Check the oil, if it’s sluggie you may want to change it. Maybe give pcv valve a shot of cleaner. Pull the plugs and check for spark. I don’t know how often this thing gets driven but you should try to get it up to operating temp and drive it at least 15 miles once a month. Getting everything in the car moving periodically can actually make the car last longer than if it were to just sit there.
+1 on the codes. Post them back to us when you know what they are.
Id also recommend taking the vehicle out for a spirited drive once a week at least if its ‘stored’.
This forum is OUTSTANDING!!!
Excellent recommendations by Karma, 3rd Gear, and thisisbuod. Getting the codes pulled is high on the list of TODOs. WRT the alternator…I think it was replaced a few years ago by the dealer (extended warrantee work) but they put in some no-name rebuild and it eventually failed this past summer. No biggie…R and R was a learning experience for me. Had to take out a piece of the inner fender well to get to the tensioner (ha). It doesn’t get driven much but your recommendation to warm it up and drive it at least 15 miles once a month is well-taken. Oil was changed about a month ago but I’ll check the dip stick nonetheless. If I can find the PCV valve, can I use brake cleaner on it? It’s harsh stuff but PCV valves aren’t that delicate???
Thanks to everyone for your recommendations. I’ll get back to the forum as I get into the troubleshooting. Will be out of town next week but will be on the case every so often after that. Thank you all again. Enzo
I just looked back on my recent reply. I guess my “newby-ness” is quite evident. My thanks should have been directed to: shomoser, thisisbuod, and dreamer2355 instead of the “gear” selection. Apologies to all. Enzo
+1 on pulling the codes. Old or bad gas can cause something like that and given your description I would say it’s not a bad idea to put a fuel additive in there. That may not be the cure however, you may need to run the gas in the tank through to get the complete fix if you find the additive to make a difference.
- You must be logged in to reply to this topic.