Rough Idle Help

[sushisean]

I'm up in Pismo Beach for Christmas with the family. Was going over the top of a dune and the front of the vehicle plowed through the top of the hill of sand. Didn't feel like a huge impact but it must have been fairly large as it knocked the trim piece around the fog light free. After that impact the idle is extremely rough and I have to give the engine a little gas when starting or it will die. It's idling at about 600 RPM but fluctuates down to 200 and up to 700 constantly. The engine is making a terrible sputtering sound. At highway speeds it still doesn't sound right but drives fine.

Any ideas what I could do while away on vacation here to resolve this? The one thing I tried was cleaning out the air filter which was filled with sand and dust. The only other thought I've had is maybe I knocked a spark plug wire loose? Need to take the engine cover off tomorrow to check that.

 

[Panzerknacker]

Not a rover mechanic myself and I havent had mine long enough to tinker around under the hood, but check the air flow sensor, right behind the air filter. If wires got knocked loose or it got fouled with dirt it could cause symptoms like that. Thats been known to cause rough idles on some other cars ive owned.

Fuel filter and lines... Spark plug wires... Get it scanned for codes at auto store, even if there is no check engine light there may be a piece of info, misfire code, could be a number of things.

 

[Houm_WA]

Yeah you'd think that it would've thrown a fault or two...maybe a "Reduced Engine Performance" message or something.

I had a Bronco II way back when and it idled rough and would die out now and then and it turned out to be a fairly small vacuum hose that had come unseated.

 

[ryan-in-oregon]

I would check for loose vacuum hoses/intake hose first. LR3's do not use a spark plug wire, instead they have a coil on plug setup and the connecters lock in place. You would also have a CHK ENG light on due to the misfire should one of these come loose...

 

[Panzerknacker]

I would check for loose vacuum hoses/intake hose first. LR3's do not use a spark plug wire, instead they have a coil on plug setup and the connecters lock in place. You would also have a CHK ENG light on due to the misfire should one of these come loose...

Dont know why that slipped my mind but yes, a vacuum leak is another cause for rough idles. Any air entering the intake system after the filter/MAF sensor could be a cluprit.

 

[Disco Mike]

First, instead of waiting for 20 responses, get the hood up and start at your air filter and work back.

 

[sushisean]

hoses after the intake filter are all nice and tight. MAF sensor looks good. I have the Mantec front guard on I'd have to take that off to check hoses under that.

I turned the car on this morning after it had been off for 12 hours. Started fine and I thought everything was OK again but after 30 seconds it was struggling again.

 

[Chongo]

I'm up in Pismo Beach for Christmas with the family. Was going over the top of a dune and the front of the vehicle plowed through the top of the hill of sand. Didn't feel like a huge impact but it must have been fairly large as it knocked the trim piece around the fog light free. After that impact the idle is extremely rough and I have to give the engine a little gas when starting or it will die. It's idling at about 600 RPM but fluctuates down to 200 and up to 700 constantly. The engine is making a terrible sputtering sound. At highway speeds it still doesn't sound right but drives fine.

Any ideas what I could do while away on vacation here to resolve this? The one thing I tried was cleaning out the air filter which was filled with sand and dust. The only other thought I've had is maybe I knocked a spark plug wire loose? Need to take the engine cover off tomorrow to check that.


All the above comments are a possibility, but if the engine is missing and the rpm is fluctuating, there should be a check engine light on. Was this vehicle serviced recently? And if so, for what reason? The reason why I ask is the I.A.C. solenoid may have been left loosly connected or any sensor may have been jarred loose. There could be a fair amount of sand before the air filter. Was there brush that you drove through as well? Anyway, there are too many possibilities with the limited information at hand. If you can have the codes read, or have further information others may get back with you with better ideas.

Best wishes…………….. Chongo

 

[dantheman1]

Could also be some excess sand fouling the t-stat right before (or after??) the MAF. When my t-stat started to go bad, I would have a rough idle at start-up. Easy/cheap part to replace too if it ends up being the case, autozone carries a tstat for a ford that's a direct swap (forget the details but someone posted them a while ago).

 

[Mhaise57]

I have searched the forums and can't seem to find it, but if anyone has the info on which Ford thermostat is a direct swap that can be found at Autozone etc, I would gladly appreciate help