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300EChuck last won the day on August 7

300EChuck had the most liked content!

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  • Lexus Model
    LS 400
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    Colorado (CO)

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  1. My goodness, I love the dance, the bob and weave, the could it be toss of spaghetti against the wall. The replacement of every single part except the door hinges. YOUR INJECTORS ARE BAD. My company rebuilds injectors, is rated 5 star across the board for the last 12 years, I own a 1990 LS 400 which now purrs like a kitty, and I have seen MANY sets of these injectors that leak down and have bad sprays. Surging, gas smell, melted cats, etc are CAUSED BY THESE BAD INJECTORS. They are fairly easy to remove -- save yourself time and effort and bad words and pre order the throttle body and upper intake manifold gaskets from Rock Auto. Pull the intake of course, makes reinstallation much easier. I'm not shilling for my biz, we got lots. I'm in Wheat Ridge, Colorado, so look us up if you want this fixed. By the way, don't ignore the cold start injector. Under the intake. It clogs solid and makes cold starts take a while. Later LS 400 models upgraded the software so the cold start was eliminated.
  2. My goodness. Haven't read all the back and forth, but 50 years plus of being a mechanic means you should RUN, or have it towed asap from the current shop. Reasons: No car in the history of the planet has 3 coils go bad all at once. Not possible to diagnose injectors unless they are pulled and flow tested. Head gasket problems are relatively easy to diagnose on the V6. Since head gaskets don't blow simultaneously, unless you SERIOUSLY overheated the old girl, the sparkplugs on either bank will be utterly absolutely clean, cleaner than the other bank. Really, the best way to QUICKLY check a bad head gasket is to smell the exhaust. A sweet smell, obvious as hell. Timing problems, more than likely. Car can easily be saved with a competent mechanic. Don't be afraid to pull out of the shop -- money spent is money gone. Which is why is use YELP, etc. Good luck.
  3. Jay: The LS 400 uses a green colored valve which sits vertically at the front of the engine, called the BVSV, or, Bi-metal vacuum switching valve. It has 2 ports which always break off, since they handle gasoline vapor which weakens them internally. When you super carefully pull off the vacuum lines, say to remove the intake manifold, bink, these ports break at the base of the valve. This valve opens at 54 degrees, and pulls gasoline vapor from the carbon canister, through the valve, and into the intake manifold through that beautiful metal vacuum tree. This valve is unobtainium, and was only $350 new when available. Yikes. It CAN be repaired with JB Weld plastic epoxy, reattaching the broken little green vacuum ports. Initially with super glue, then with a nice dose of JB on the exterior of the ports at the base, making sure the ports aren't plugged with epoxy. Or, use white vacuum tees available at NAPA, trimmed to fit. I have NEVER seen any first gen LS400 where this valve is in one piece and functioning properly, except mine of course. 😊 The carbon canister can itself be tested to make sure it isn't plugged or has a broken check valve (this from the official factory repair manual). The top of the canister has two outlets. Blow low pressure compressed air through the larger outlet; air should flow out the other port at the top (the purge port) AND from the bottom port, without resistance. Then, blow compressed air into the smaller port at the top (the purge port). NO AIR SHOULD ESCAPE FROM THE OTHER PORTS, top or bottom. This tests the check valve. If it fails this second test, replace the canister. The canister might fail the first test, but that's because the internal filter is plugged. This can be cleaned by blowing 43psi of compressed air into the larger port at canister top, while holding the purge pipe closed with your finger. Air should freely come out the bottom port. No activated charcoal should come out. And, you can't wash or clean the canister. Simple system. Hopes this helps. Chuck
  4. I love the back and forth on these forums. You'll get some white smoke, but only if the temp is way below freezing and that now hot moisture in the exhaust meets cold air. How can a stuck open exhaust blow the cat on the other side of the engine? In the intake process, there is always a bit of intake fuel mist coming back up through the intake valve before the valve completely shuts. Enough can kick back through to the other half of the Vee to richen up every cylinder. Newer cars don't use an EGR as such. Valve timing can be varied enough to pulse a bit of exhaust back into the intake. Thus, lower temperatures. TAH DAH. Great idea until low tension piston rings and direct injectors happen to be present. Best tool I ever bought was the kit to blast the back of the valves after the intake is off. Hello Audi V-10!! Takes care of my boat payment. Been using Walnut shells. Car Wizard likes a charcoal type of mix. He has info on one of his videos. Haven't tried this mix yet.
  5. Head gasket is possible, but you will smell antifreeze out the exhaust, not gasoline. To blow a head gasket you would need to massively overheat the engine, as in pegged temp gauge and steam billowing everywhere.
  6. You guessed it. Injector stuck open. I have an extra good (tested 4 different ways) injector for this. Price is $50. Has been rebuilt and is the OFFICIAL Denso injector. Bosch doesn't make one for this. Nor does Standard. Our business is called Fuel Injector Specialists. I also own a 1990 LS400, which is how I happened to be here. Suggest you pull all the injectors. Not too bad a process, the forums have a helpful video available. ALSO PULL THE COLD START injector, which is at the bottom of the plenum. See why I recommend pulling the Intake? You could buy the one good from us, or send in all 9. $20 each complete rebuild, with pictures before and after. Or, not do anything at all, and wipe out those 3 cats. Phone number is 303 456 0789.
  7. Didn't put the FOB in the tank, I rather imagine they opened the gas tank door and set the key next to the tank opening. If the FOB ended up IN the tank, you've got some serious problemos. Sometimes poo happens, I've never bought a car over the net, had it transported, or flown to a city 1000 miles away for a neat little Benz with some hidden damage, etc. that there wasn't an unexpected "surprise." Ain't no used car, or non-museum car actually, that an expert mechanic couldn't put on the lift and start legitimately twisting wrenches. Diff torn up while loading or unloading on the transport would be my guess. Just add the cost of diff replacement (I still say online junkyards -- have had good luck with them) put onto the cost of the car. Make friends with a good mechanic in your area. Diff replacement shouldn't be outrageous. THIS IS A JAPANESE CAR. This is a quality Japanese car. Designed to be repaired. Read: un-German. Life is short. Hell, you could own a Chrysler 200 where the trans blows one month out of warranty.
  8. How they get away with it is beyond me. Bosch won't allow fake injectors with the Bosch symbol. They do so much biz with the Chinese, that the Chinese government will shut down the fakesters. Denso? Probably not. Chinese philosophy is that the Americans will buy cheap. Period. Quality? Not so much.
  9. Sorry, I was rereading your original post concerning injectors. Denso no longer makes injectors for this engine. My business is rebuilding fuel injectors. We have found that Chinese injectors are being made with DENSO and the original part number printed on the side of the injector. Printed, not cast into the body. These are fakes. We've seen these on Tacomas and other Toyota products. Just tested a set of this junk where, out of 8 injectors, 2 had terrible spray patterns, and one was already dead. Plus, the mechanic reported the cat almost melted because the engine was running so rich. Besides the pattern problems, these "factory" replacements were 15% bigger than stock. Here's a warning sign: these fakes cost $50. For a set of 6. 😖 I need to get on the forum under fuel or whatever. I just finished a perfect set of LS 400 injectors, fit 1990 - 1994. Factory official, etc. Don't get any better. $50 each.
  10. Quick reply concerning timing belts: Had a mechanic who I thought was super good replace the timing belt on my LS400. This was one month before I bought the car. Found the receipt in the glovebox. Motor was a bit rough; cleaned and flowed injectors took care of that. Small noise from the P.S. pump. New seals took care of that. Small grinding noise at idler pulley. New bearing (available separately at Whisler bearing, give them the part number on the bearing itself. Ran about $10. Now I could reuse the original metal pulley. Old bearing pressed out and in fairly easily. Side note: the same bearing as the idler bearing in my 98 Saturn SL twin. Very common bearing.) So. More grinding noise at the front of the engine. Blah. Took the front of the engine off and found that whizmo mechanic reused the original tensioner bearing for the timing belt. Bad words. Since he charged $400 for the complete kit. Available for $100 from Rock. Mechanic later fired and came to me wanting a reference. Sometimes I wonder ..............
  11. Alas, entirely possible that the differential needs to be replaced. NO NEED TO GO TO THE DEALER. In fact, do not go to the dealer -- what you need is to replace the entire unit, as in used part. Thanks to the internets, and lots of wrecking yards nationwide posting as to parts available, bet you could find a complete good used unit for $500. The Fedex weight limit is 150 pounds, so you will be okay. Don't even attempt to have the existing unit rebuilt. These go bad (noisy) usually due to a bad bearing. Gear interfacing gear is usually no longer on the centerline. Bearing can correct this, but now the gears have worn off center. YOU WILL NEVER HAVE A QUIET GEARSET. I've rebuilt every component on automobiles, having over 60 years experience. I warned a neighbor about this problem when his Pathfinder differential got noisy. He replaced all the bearings, some gears, and wasted nearly 6 mos of effort while the vehicle sat. His main issue was that this is a common Junksan issue, few junkyards nationwide have any good ones. Lexus? These almost never go bad -- unlucky you I suppose.
  12. Or could it be 164 different idle values? Up 4 different values, then each adjusted downward by one of 4 different values? My brain hurts.
  13. Oops. Was busy servicing some injectors, and I quickly replied to this post. Ahem .... NEGATIVE voltage goes to the S1 - S4 terminals.
  14. Aaahh ... Missing an E fan..... Could be that the missing fan completes a circuit. I have the shop manual for the 1990, official $300 manual, and the diagnostic for the Idle valve is VERY interesting. On this 1990, you apply positive voltage to the center two terminals of the valve itself (after disconnecting the plug), then apply positive voltage to the remaining plugs (S4, S3, S2, S1) in that 4 to 1 sequence. Imagine the number of jumpers you need. Positive voltage to S4, keeping it positive, adding a positive jumper to S3, etc. At the end of this sequence, the valve will open. Then, pull the S1 to S4 jumpers. Then add positive voltage to S1, add to S2, add to S3, add to S4. Reversing basically. Then the valve will shut. 4 idle positions. Once S1 is okay it would open a calibrated amount, then continue to S2, etc for an additional amount, etc, up to S4. Quite clever indeed. Some complex little circuitry. Either the idle air valve is bad, or the missing fan is a culprit. Just a guess, but imagine the 98 follows the basic logic of the 90. Hope this helps somewhat.
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