i have a '93 Pathfinder that ran with the thermostat stuck open for 40,000 miles. finally, i replaced it when i got the car from my dad, but it missed a lot and ran rough when engine was cold. now, it also misses some and runs rough when warm, too. but here's the weird part...if i turn the A/C on, the engine smoothes out...why is this?? you'd think i'd be the opposite, wouldn't you? i tried replacing spark plugs and wires, didn't help at all. my theory was that there were carbon deposits on the inside of the combustion chamber due to running cold for so long, but why does it smooth out when the a/c is on?
2006-08-29 15:04:40 · 7 answers · asked by Anonymous in Cars & Transportation ➔ Car Makes ➔ Nissan
The Idle air control AC idle control speeds up the engine thus masking the roughness. Try squeezing the fuel return hose yes one of the two hoses on the passengers side of the running motor squeeze the supply hose engine dies try the other. If the engine smooths out look for fuel system related problems clogged injectors. And did you take off the distributor plug look into the connectors for any bent pins or pushed back connections. Some things to try replace the fuel filter above the rear axle? have you driven this truck like dad never did?
2006-08-29 15:19:54 · answer #1 · answered by John Paul 7 · 2⤊ 0⤋
really the only possible answer could be,,is when the air is on,its running in a strain,but like you said,,why now,,there is one other possibility ,it may have a bad temperature sensor for the computer,,since it was run cold for so long,it may not work right now,,when it gets hot,,i once worked on a Toyota corolla that ran good with the air on,,but missed when it was off,,it had a bad temp sensor on it ,,i own a repair shop,,and have run across some weird things in the past 35 yrs of doing this,,you might try a temp sensor,,it may fix it,,good luck with it,,i hope this help,s.
2006-08-29 15:16:15 · answer #2 · answered by dodge man 7 · 0⤊ 0⤋
I'm not exactly sure why it would do that, however, when the air conditioning is on it dumps more heat on the engine warming it up which explains that. If you haven't changed the oil recently that might help too.
2006-08-29 15:10:49 · answer #3 · answered by Maestro bestofthebest 2 · 0⤊ 0⤋
Better go back to the first thing you have done in the car for the answer you seek. Your solution would just be there, waiting for you on your first work on the car, the replacement.
2006-08-29 15:09:24 · answer #4 · answered by wacky_racer 5 · 0⤊ 0⤋
leave out the thermostat permanently. try it unless you live in a cold state. good luck.
2006-08-29 15:09:25 · answer #5 · answered by briggster15 1 · 0⤊ 0⤋
Sounds like it could be a vacuum leak.
Check all the little hoses and fittings.
Good luck.
2006-08-29 15:06:55 · answer #6 · answered by pukcipriavroc8v 4 · 0⤊ 0⤋
Have you checked on the electric clutch on the AC unit.
2006-08-30 10:04:39 · answer #7 · answered by Anonymous · 0⤊ 0⤋