so i was on the way home from work today and i came up to a stop light and my car sort of lunged forward a bit and then almost died. the idled fine. i went to take off and at first it felt like it didnt have the power it should..i gave it a little more gas and it took off normally. came to a few more stops and it didnt repeat..got home,opened the garage door,pulled in and let it idle..and thats when it started doing it..idled up to like 1500 or so then down lower than normal..then idled fine for a few..then repeated the surge. just so none of u jump on the caps/ecm thing..i already had mine done almost a year ago and i just got back from a 1300 mile trip to washington and back. im thinking tps or iac valve. no check engine light on. any info or advice would be appreciated. thank you

 

Must be an LS460

 

lol..sorry 92

 

80 reads..0 replies. awesome..reading through this forum is pointless as no one follows up anyways..thanks

 

I would suspect what you had mentioned and a possible vacuum leak. Optionally a fuel pressure issue. You've read many of the usual idle issues so you are aware of the typical fixes.

 

was hoping someone who actually had this issue would comment on what he went through to fix it..thanks ra40
i started reading but i gave up after so many threads where people had problems but never bothered to post if they fixed i or what they found. going to take my iac off and clean it..go from there.

 

Check the pcv. See if it's stuck.

 

Out of the blue problems. Not on an LS, I have had carbon debris hold an EGR valve off its seat and cause idling problems. It will cause a vacuum leak. I hope I have the problem some time I'll do a write up on it.

 

just drove the car around..parked it and let it sit for 10 minutes idling..no issues. i friggen give up. my car is haunted..anyone know of an auto exorcist.

 

btw it did this exact same thing when my alternator died..ive already checked voltages..car off..car idling..car idling with load and rev with load on and off

 

Transient issues, could be the quality of fuel used, could be carbon deposits getting in places they shouldn't, could be condensation or H2o causing some sort of problem, maybe an electrical connection or lack there of. Just have to wait till it either keeps it up for ever or stops dead on the road someplace.

 

when was the last time you did a tune up? plugs changed? caps and rotors? afm clean?

and please don't get too impatient, if you want instant answers go directly to your mechanic. i understand your frustration (even about folks not following up on their fixes).

 

car is tuned(dealer wires/plugs,and caps/rotors)..im **** as ****** with my car..its been driven for a few days since..no issues. btw im not touching my afm..i have another one laying around so if it comes to that ill just swap them out. i did change the hose from the fresh air intake to the iac valve..and the connector was already broken on the fresh air hose! had to fix that.

 

I happened had a chance to see the similar surging problem today at my local shop where I sometimes visit. It's a Toyota Crown which has a 1UZ-FE engine. The problem was caused by the vacuum leak at the gasket used at the intake manifold like RA40 mentioned at the post #5.

The shop owner quickly found the leaking point saying to me, "I'm good at these common old problems but not electronics affairs like someone".

 

someone meaning u yamae the problem hasnt resurfaced since..thanks for the response btw