mdm6713

Ok been dealing with this car, now when you start the car(cold) the engine wants to rev up and down...like a yoyo. Eventually after about a minute it settles down and idles normally, a little high, then gradually comes down as it should. I think I may be dealing with a faulty IACV Idle air control valve any ideas? BTW this is a California model, and the IAVC is a little bit bigger than most GS's and there a Thick(maybe 1/2") tube that runs into it housing, at the top of it. When you unplug the tube, there a lot of vacuum from the tube end...which runs into what looks the fuel rail. If you hook the hose up too fast the car will stall out. Theres no check engine light anymore. Driving it runs great. thanks for everybodys help in all my troubles

Someone please offer advice on installation of the TPS on a 1993 GS300. Theres no OBD2 avail on this model, how do you adjust it properly? thanks a lot

Thanks for the reply. The sensor your talking about is the MAF or the Mass air flow sensor. Im not sure really how to clean is either other than some dilicate solvents to spray in there. As I understand, theres an elment in there similar to wax..its cooled by the amount of air that passes and give that reading to the ECU. Sorry to say I still have a problem, Im about to go GUN HOE and take the TPS off of my dads car to try to swap it, but im affraid then Ill have 2 broke down GS's! Anyone familar with changing the Throtlle Position sensor on a 93 gs300 ? please help! michael Hi there MDM I am over the water in UK but booked in here to pick USA brains as well So returning the favour I hope I have had my GS300 Mk1 (same as yours over there) for only a few months, and it had basically sat in the previous owners garage for 4 years and did less than 500 miles in that time I had bad idling and lack of power as well and stalling although it was ok when I bought the car, it started playing up soon after I took off the throttle body and it was like a barbeque in there so I took it off, not a bad job to do, all basic unscrewing nuts and hoses, don't forget the water hose half hidden underneath the body but you can get to it Mark the vacuum hoses with a little tippex or paint to make it easy to put back on Cleaned it out with carb cleaner and a rag, cleaned out all the vacuum hoses and checked and cleaned the sensors Now here was the lucky bit I found my problem and my cure by accident Just after the air filter box is an air sensor it looks oblong and has the electric plug on it, i took that out and couldnt work out how to clean it or what it really did, it is held by 3 phillips headed screws I reassembled the lot and started it up, and it ran lovely smooth and even and a quick drive and the power was back Getting back i opened the bonnet and checked the connections for safety and found I hadn't tightened those 3 screws on the sensor, so I screwed them up tight Back in the car and it ran like a sherman tank, now i thought thats daft what happened ? The only thing I did was tighten the 3 screws so open the bonnet and slackened them off again and it ran beautiful i tinkered !Removed! in and out and found just tighteneing them finger tight worked well Now I am not sure obviously if this is your problem, but thats whjat it was on mine Good luck

Im getting pretty depressed here replying to myself here! Im still having problems with my gs300 1993. Problem is is wont idle, its OBD1. Funny thing is the check engine light and trac light will go on and off, its mostly on at idle when running rough, but if you rev if it, the lights go out. I have dont plugs, wires, car rotor and now o2 sensors, it runs great when it moving, but wants to stall at low speeds and stops. The current codes are 21 28 31 (O2 front,02 right, Vane air flow?) I have no idea what Vane air flow is, I think its the TPS and I have one I can switch out and try, but im unclear of how to install it. Any suggestions? please advise

Guys???? Nobody has any clue about this? Has anybody seen the GS300 with an idle that just wont maintain? Its down to practically nothing at time(400 rpm) then maybe bouncing around to 1500 etc etc...any suggestions folks? please!!! thanks Michael

I should also add about this car.... The plugs (all 6 identical) where covered in soot. fouled out bigtime. I tried changing the Ignitor, and the Ignition Coil (swapped from my dads GS) No differance Im pretty convinced the problem is either.. 1. TPS 2. o2 sensors 3. Both 4. other The thing that Im hung up on is the fact that is wll run smooth, then all of a sudden start boggin down and acting viotlile, like a man walking down the street in good health, then starts vomiting ramdomly This makes me lean toward the TPS since its "intermiddent" or whatever.. Thing is...on a 93' no OBD2...so how do you install it? Im waiting on a scan tool in the mail now, then Ill have codes, until then...any suggestions would be helpful, Im have the benifit of using my dads car to sawp parts with, although the ICV is differant. The problem car is a CAL model. please advise

Hey guys please help me out on this one, I removed the distrubutor to replace a leaking oring. Well I didnt really pay attention to what i was doing. I removed the whole dist. assmebly before taking the cap of and looking at the rotor buttons direction. The gear turned as I pulled it out and I dont know where to re-insert at. A friend of mine has the same car, we pulled the timing cover and the cap,....lined the white/arrows on the cam gears up. the the distrubtor was pointing towards about a 1:30 (pointed toward the #1 plug) position if your looking straight at it. So I set mine up the same way, and its just puttering...sounds like no power...i can turn the dist. and it would help slightly, but not the purr i had before. Ive pulled the dist. turned and re-inserted about 10 times now, im just thinking...am i missing something? Maybe Im not in the right position? Any advice please, this is my dads car, and he needs it back! lol thanks guys

Hey guys..93' gs300 runs really rough. Its pretyy much fine when it moving. Except when it comes to a stop it might stall. well today I put 6 iridiums in it, new VC gaskets, cleaned the intake and egr well.I t runs really smooth at times, then all a sudden it will just start running terrible,...I hooked my timing gun to it and it was all over the place, but the idle isnt consistent so I dont think the reading means anything. Also new wires, cap and rotor, got 167K on this car. I also cleaned the Idle Air Control valve. Check engine is on also but i dont have the tool (yet). Im thinking TPS? (throttle position sensor). Help anybody! thanks