davespall

So i got my car disgnosed and code 71 came on. I am thankful to my current mechanic who was really honest and checked the whole egr system throughly and found that one vacuum hose coming from throttle body going to the "P" section in EGR modulator was not passing any air. So he cleaned the throttle body really good and so far no 71 code appears. But now my car started giving me a jerk while driving around 50 to 60mph. I believe thats because of old spark plugs or fuel pump going bad. Any suggetions?

davespall

Any to everyone, i have alot of LS owner frens and everybody say that its a bad ECU prblm. Because ECU tends to hold the idle. I might give a try installing ECU from my frens car and see what happens. Will surely post back once i figure this out.

Xenoblade

So did you try your friends ECU? Did it make any difference? Please let us know.

davespall

No not yet because all of my frens are pretty far from me lol noone wants to drive to me and i dnt want to drive 1.5 hrs. Lol

Andyboy980

Check your pcv valve I had the same problem

KJG92

I just thought the tach was lazy. I've played with the TPS and even with the throttle cable. When it reads right on the dash you can tell it is too high. I had it right at 600 in park and the car jerked hard going into gear and it will pull on its own. I set it back and just forgot about it. The PCV is one thing on the list to replace.

Yamae

The ECU for a 95 is programmed to adjust the idle speed 650rpm at P or N. But when the throttle body and the IACV are badly clogged, it is often the case to go down lower than 650rpm. So cleaning those 2 is one of the ideas to fix the low rpm problem.

Bercasio

iTrader: (1)

I ran through the exact same low idle 400 or less issue for quite sometime with my 99 LS4. At first the Lexus tech did anything and everything related to cleaning throttle and diagnosing. Also cleaning the MAS and IAC, Checking the throttle position sensor to the accelerator sensor, etc. No hard codes shows up, while still at low idle in drive. To the point he even swapped out ECU from another 99 LS4 and same low idle issue!!! So I drove the car the next 3-4 days with the low idle issue at 400 or less, then all of a sudden my car would loose acceleration and go into limp mode. I would drop into neutral fire it up, then it would start again, then for go for another few hundred feet, then limp mode kicked in again with chk engine light and vsc indicators goin off, fortunately enough this happend close by to my Lexus dealer I get serviced at. So I peddle my way by restarting and roll then repeat process. Lol! When I pulled in, the service rep brought out his diagnostic module and ran a check and a code finally kicked in, it was P1128(throttle motor malfuction)@ 302,000KMS on the odometer. Fortunately enough being at the right place at the right time a few years back, I was with a friend at a specialty shop that brings engines from Japan and there was an intake manifold with the full throttle body assembly from either 98-99 Celsior they brought over in the mix with a few other jdm engines just sitting there on the shelves ready to be taken apart. It also had a tag on it stating it had only 58,000kms on it. My gut told me to snag it, so I offered to take the whole thing for a killer deal knowing how much these go for. In the end the Lexus dealership could not believe I had an extra assembly laying around for a few years. As apparently the throttle motor alone is pricey piece. So I saved a bit of $$$. In turn we re-re just the throttle assembly holding the newer accelerator and throttle sensors along with of coarse the throttle motor. Once complete and fired up. The low idle was gone?!?! No codes at all!!! And I have never experience even alot better throttle response till now. The Lex tech thinks with the low idle issue, it maybe be a "possilbe" symtom that the throttle motor is failing but not enough to throw a code oddly enough till it's actually operating at less than 50% or not at all. But all I can say at this point for the past month, everything is all good and idles quietly around 600-650 mark. Another area to consider. Hope this helps ya'll!