NIALS400

I have a similar problem, did anyone get theirs resolved. Did the coils rectify the situation? Thanks for the update.

Mine's the same way. It never does it under load, uphill or coasting. I called a bunch of dealers, Maplewood, Wayzata, Betts and some in California. All said it would need to be looked at by a technician. Sounds like a canned answer. I did notice that I do not have a Lexus brand fuel cap and it isn’t for a vacuum only system. I bought a replacement at a parts store to see what happens and I'll order a new Lexus one on Monday to see if that helps.

From what I've been seeing, the Toy cross would be a 95-99 Avalon. Mainly any mid 90's with the 1MZFE 3.0L engine. I'll try my local in the A.M.

What could the aftermarket do? The one I took off had an S on it which I assume was a Stant after market, this one is as well but is marked vacuum only. The closest Lexus dealer is 120 miles away, is there a cross reference to a Toyota cap? I do have a Toy dealer 10 minutes away. Thanks

Well, I got a new cap this evening and noticed the construction is quite different from what is on the car. The new one has no inner baffling. I am now suspecting the previous owner put a cap that fit that was NOT for a vacuum only system and that may be contributing to my intermittent chug, not really a miss but loss of power for a split second. The new cap specifically states VACUUM ONLY. Hope it works.

I may have a full set of 4 with caps and near new Blizzak's installed. Shipping may be an issues, what state are you in?

BlackLex, how long has yours done this? Did it do it in warm weather? Since I'm in Iowa maybe its the cold?? I just bought mine so it’s been cold here since ownership. I drove it yesterday when it was -5F and it didn’t act up that I could tell, this morning at 10F it did only once. My next step is to add some weight to the rear, tube sand, and see if maybe it the suspension? I did change the trans again and filled with only 2 qts. but haven’t drove it more than a couple of days in which it acted up once, maybe it will take a little bit to purge? I'll turn the TRAC off again and to the POWER trans setting to see if it makes a difference.

Curious about the fuel tank pressure. I've owned my 91' for a couple of months now but have never filled the tank after driving for more than 20 minutes until today. I noticed that there is a great deal of vacuum in the tank after I removed the cap. Most of the time I don’t hear any depressurization when I remove the cap. What is normal? I know after the car sits for a couple of days and I fill there is no sound. Is it time for a new cap? Could a bad seal be the culprit to my engine miss feeling while cruising at highway speeds? After market OK or go with OEM, the cap on it now says STANT? Sorry for all the questions, just trying to learn. This car is much more sophisticated than my 82 Supra was.

I've done the trans drain and fill a couple of times, with help from this board, thanks to all, but to no avail. When I do, do the drain and fill though I put in 2 qts. and it barely touches the dipstick when cold, usually I have to put in 2.5 qts. to get it to the middle of the cold mark. I'll drain and fill again and only put in 2 qts. to see if that makes a difference. Maybe over filled tranny? I did drive around for about an hour today messing with tire pressures, not difference. After I went to fill up and noticed there is a lot of vacuum in the tank, is that normal?

I'm still looking for the problem. One thing I did notice is that my fuel cap is a Stant, I can only assume the OEM is not made by Stant. Could improper fuel tank pressure be the culprit? Where is a good place to get a replacement OEM at a fair price since my nearest dealer is 2 hours away?

The car did it before I changed the timing belt, W.P., plugs, wires, caps and rotors. It almost feels like the TRAC kicks in for a split second but it will do it with it on or off. Tried it in overdrive or out of O.D. The tach doesn’t move, its weird. I do have blizzaks on at 35psi. There a hard tire so next I’ll try dropping down to 30psi.

I’ve noticed the same thing with my 91’ and usually on black top roads. I don’t know if it’s frost heaves, in the frozen north as we both are, or the reaction of the suspension or something else. Did you figure yours out?

It starts ok but does take about 3-4 seconds of cranking when cold. Would replacing the valve change the cold start crank time? Are the air control valves available at part stores or only from Lexus?

I have a LS1 and the large vacuum line, or what appears to be a vacuum line on the front of the intake is cut and plugged with a screw. It’s the one to the right under the Lexus badge. Is this important or no big deal? Thanks.