TigerFish

I think the number of active particiapants in the thread is due to a few things IMO. MB's are very common, so a lot of owners to pick from. In general (yours being an exception in the main), Lexus are very reliable, much more so than MB. Far fewer Lexus owners looking for help to find the forums. Of the relative few Lexus about, even less of those are GS's. They are fairly rare beasts. Yup, you have to undo the nuts behind the trim either side of the boot opening and unbolt the clusters. A bit of a PITA, but the only way. You can disconnect the battery instead. Just make sure no security code is set on the stereo. If, when you switch the stereo on the word "SEC" is displayed momentarily (can't remember which one of the two LCD panels it shows on), then a code is set. It will activate if the battery is disconnected and won't work until the code is entered. As the code is set by the user when it is enabled, you need to know it. If "SEC" doesn't show momentarily, then there is nothing to worry about and you can go ahead with a disconnect. As far as I remember, no battery backup for the alarm. Once it is disconnected, it can't sounds the alarm. I don't recall mine going of on the reconnect, but your call with that one. You could disconnect tonight, reconnect in the morning.

MAF is worth a clean for sure as a starter for 10.

That bulb should still work :)

Just keep in mind the O/D light is not related to the IAT/MAF issues. It indicates transmission faults. The check engine light is the one relating to the codes you are reading. You need to clear the codes to reset them, so I would pull the ecu fuse(s) for a a couple of hours and then reconnect. It should (fingers crossed) at least clear the TPS error permanently. It may clear others as well. The bulb failure lamp should work by A ) if it comes on when the side or headlights are switched on it is a rear tail light. B ) If it only comes on once the brake pedal is pressed, it is a brake lamp. If they are defiantely all ok (including the high level brake light if your car has it), then I would think one of the bulbs is not in great shape and may be worth swapping them out for new bulbs anyway.

Looking at getting a new exhaust for my GS430 Sport in the next couple of months. Nothing wrong with current exhaust, just fancy getting some of that V8 growl going. anyone used any places, especially around the Hampshire/Berkshire area to get a custom made cat back system? There are a couple of places on ebay doing them, one in Leeds for £299, but a fair treck in time and petrol to go there. I don't want straight through noise, just a light sport level. Thanks for any suggestions :)

Good stuff, glad progress is in the right direction. Did they not have a MAF at the same breakers?

try some of the sellers on ebay breaking old GS's mate. Either that or one of the breakerlink type websites.

That was the one I mentioned before, on the side of the throttle body and held in place by a couple of screws.You can slacken them slightly and twiddle to an extent. From what i understand, the ecu will relearn the position, it is more to do with the pot wearing out slightly in its normal rest position. Just have a little play.

OK Fair enough. If it is stuck open, and not warming enough, it could be the issue. Hows the temp guage sitting? Again, fair enough. But as I said, not aware of any known issues around this on the GS, EGR issues in general seem more diesel related. No reason not to delete it I guess, but I would concetrate on the broken things first and then move on to the other stuff once things are running sweet. When the O/D light flashes there is a transmission fault, not linked (directly anyway) to the check engine/engine managment light which is on due to the IAT code (and possibly others). So I think a transmission fault is likely to be the reason the box is holding back. Ah, good and bad then. Could be more than one fault, but atleast we will know what they are. Does the a/c lamp on the climate control flash at all? I would expect the main reason the clutch will not engage is if there is no refridgerant in the system. I would expect it to protect itself to not try and compress something that isn't there to compress, if you see what I mean?

Also, was the IAT fault code the only code? It can hold more than one and they will be flashed one after the other until the "finished/no more codes" code is flashed.

I thought the engine was warming up to temp? If the engine stalls when the maf is disconnected then it isn't being bypassed with any default modes, so maf may well be ok, that's not to say the IAT code isn't an issue though. What are your concerns with the EGR? I'm not aware of any issues with the setup on the GS. Is the OD lamp is still flashing? I would imagine the gearbox is in some kind of "limp" mode if it is, and probably why "enthusiastic" driving is being stopped by not kicking down.

Does the car run the same or different with the maf unplugged? There are second hand ones on eBay, one with a starting bid of 99p.

Depending what you mean exactly, the slide pins should move freely, but the bolt through the calliper and on to the end of the slide pin shouldn't move. There is a link in my sig to overhauling the slide pins which may help.

It is part of the MAF, and may well be visible down the MAF body. Fault code 24 will cause a default override of the faulty temp to be reported for the air temp. Yup, too high. From memory, it should be around 650'ish. Throttle cable, cruise control cable, gearbox (kickdown) cable It isn't an unusual amount of cables for the features (i.e. cruise control and auto box) The joys of environment friendliness in the main I guess. Having said that, Never had any problems with that side of things when I had mine (I had other issues - but not fuel/ignition related). At least with that age of GS, there are old technologies like plug leads and dizzy caps, you can twiddle with the timing and all sorts :) With reference to your earlier post and spark plugs, it is a bit of a pain, but the throttle body does need to be removed to get all the plugs out. Not as bad as it sounds, and despite the quantity of vacuum pipes, it all goes back together pretty easily (be aware of the cooling system poipe connected to the underside of the throttle body though, probably the most awkward pipe of them all). this label helps with the vacuum pipes (not euro model, but still helps with the majority) and this post too http://www.lexusowne...showtopic=73070

Just think how much it would be if it was complete and had the overdrive switch still in it

Any pics?

With regard to pic 2, I don't think anything should be connected to there, but there is a trim/cap missing off the end. Not sure if it seals the end up or not though, or just a dust cap type arrangement.

If everything is fully warmed up (on warm up, the idle is pretty high), you may need to tinker witht he TPS (throttle position sensor). It is on the side of the throttle body but I can't specifically remember too much about it. Maybe two screws I think, and it can then be moved slightly. I'm sure there are some topics about it on here somewhere. Code 24 (IAT) is the Intake Air Temp sensor, which is part of the MAF. Is it plugged in OK/Needs a clean? Maybe you could've been closer with a MAF problem than you thought, even with a slightly different issue.

Can't comment on the comparisons between the LS400 and GS300, but the GS300 will cruise at the the speeds you mention with little effort. The performance difference between a GS300 and GS430 is quite considerable, the GS430 has some serious get up and go. That's not to say the GS300 isn't nippy, but in comparison to GS430, feels quite pedestrian.

What sensor wire are you looking for?

The one under the dash is the mirror of the one in the engine bay. Memory is a little hazy these days as it has been a while since I had my mk1, one engine bay socket is a rectangular one at the front end of the plenim chamber on the inlet manifold, where is the second one you mention? The pic below is the under dash one, all the pins are the same as the one mentioned above in the engine bay, just a different shaped connector. You can do all the same things from either socket.

The GS430 is pretty much on a par with the GS300 fuel wise, so would be very close with LPG too. Luckily for me, I went from 35k miles a year in a GS300 (non LPG) to about 5k miles a year in the GS430 (non LPG), so petrol bills are very much lower for me regardless :)

The ecu itself isn't as far as I know, and any jiggery pokery done outside of it will be relearnt by the ecu to counter act it, so pretty difficult bar a replacement standalone or piggyback ecu. Well, that's as far as I understand it anyway. No cheap gains power wise. Either a later car, or the jap import version of the GS300, the Aristo twin turbo (or the later V8 powered cars, the GS430).

They have a reader, but not one of the cheapy DIY price range pieces of kit. I'm not aware of a cheap option, and certainly not an OBD one as they aren't compliant, but if Steve has seen one, then fingers crossed. Even the early mk2 GS's weren't compliant, only from 2000 onwards. I have a couple of readers that work on my odbII GS430, they work very well, just not on earlier cars :( (Lexus that is - one of them works nicely on my '94 Corrado VR6)

Mk1 GS's (jzs147) isn't odbII compliant, so no readers available. Paper clip and counting the MIL flashes is the only DIY'ers option I'm afraid.