1989 TT Auto. I took the Z for a run to Brissie last week and found the cruise control no longer "sets". Where to start looking? The "cruise" light comes on but no matter what you do, it will not set. Tried this at many different speeds, still nothing. The clock on the centre console switches itself on and off (and resets) randomly. I feel it is loose wiring but thought I would get some feedback before tearing my car apart. I changed out Engine and Trannie fluid the other week. They both look a touch overfilled. Does the engine have a plug to identify max fluid fill level? There is about 6-8 square head plug randomly plotted just above where the sump bolts on. Is there an easy way to drain a little fluid out of the Auto box? This is the drop pan box (no drain plug) I am getting the Drive shaft uni joints changed out next week, is there anything else I should do while it is up getting this done. 126k on the clock, I was thinking a change of diff oil. Anything else?
Sorry, last one, I have a flat spot in acceleration. Nothing major but has just started recently. If you ease the accelerator in P, the idle will drop about 200rpm before picking up. Does not concern general driving. I adjusted the TPS about 6 months ago, would this need to be done again? Should I check something else?
Things to do If it's on a hoist it'd be a good idea to check everything under the car, start at the front & work your way back. Oil leaks, rubber bushes, exhaust leaks, starter motor security, missing bolts etc. Only do this if you can do this yourself, they'll charge you a fortune if the mechanic does the inspection & chances are he might not do it properly anyway. Have fun!
Have you checked the TPS setting to see if it has changed from where you set it last time? Checking the TPS setting would be a good place to start.
Cruise control The diagnosis for the cruise control is on pages EL-99 to EL112 in the electrical section of the workshop manual. You can download the manual from the tech section
I would check the switches down near the pedals for functionality. Commonly there is a rubber grommet that press the switch mech and these can perish over the years and stop the switch from working. For the light to come on but no set procedure, I would bet its s false signal from the pedals. The rest of your q's, east coast has answered them pretty well. Only addition I have is to clean and check your afm. Make sure the plugs free from corrosion, etc.
No I haven't yet. I did consider this may be a good place to start. Not overly happy if it has shifted in 6 months though.
? Switches at the pedal. I have the control unit up on the right hand side of the steering wheel. Is there switches at the pedal as well?
I thought possibly loose wiring but if it maybe on it's last legs, I won't bother with it. A new stereo is going in, in the next couple of months and it looks like as good a place as any for USB port, etc. Engine. I dropped 2.5L + a little on the ground. I put in just under 3L but it seems to be sitting just on the wire above full mark on dipstick. Auto box. I dropped 2L, put 2L in. The fluid is too clean to get and accurate reading but to my judgement, it looks to be about 3mm above full mark on dipstick when hot. I know about the dipstick. Some engines I have worked on, have a filler plug. You fill the engine until the oil drains from the filler plug. Let the oil drain until just dripping and it is at correct level. Square head bolts. Sorry my mistake, these are on the auto box. I can't find info on them anywhere. I may post a pic in the next couple of days but there is about 4-5 on each side of the box. You had me worried with the unis. After checking, it's a one piece unit. All good. phew! Oil change was on the list. A while back I bent/cracked the down pipe on the exhaust. Because this has to be undone and moved out of the way, I'm considering replacement of some or all exhaust components from down pipe to rear. Any suggestions? There is a small oil leak where engine and auto box connect. Exhaust has just been "repaired", no leaks. Bushes is a good thought, thanks. All the bolts, mechanical wise, are there. I am getting the fascia repaired (again) soon and will do all the missing body and stone guard bolts then (crap loads missing). Thanks for the help!
Re the cruise control. There is a switch on the brake pedal to cancel the cruise set when you hit the brakes. On a manual, there's one on the clutch as well. Easiest way to diagnose of it's the brake pedal switch that's out of adjustment is to drive along a straight road above 50 kph with the cruise control switched ON, put your left foot under the brake pedal, and pull it back towards you, then try to set the cruise. If it sets, then let go of the brake pedal with your foot. If the cruise cancels straight away, then the brake pedal switch is out of adjustment or the pedal return spring is busted or loose. The cruise cancel switch can be readjusted by loosening off a nut on the front of the switch, undoing the switch connections, and rotating the cruise switch in on its thread until it sits closer to the brake pedal rubber, and try it again. Make sure you get the right switch - the brake pedal has two switches - one with a black plastic end for the brake lights, and one with a blue plastic end for the cruise cancel. Try this first and let us know how you go. There are other things to check, but this is the first one. Re the driveshaft. If it's out, replace centre bearing. If you have cash, get it rebalanced too, just to be sure. Clock - possibly the most unreliable bit on a Zed. Easiest fix is to find a known working one and change it. Or, chuck it out - you'll never be late in a Zed!!! Flat spot in acceleration - If it does it without a load on the engine, ie while in park, it does sound like a TPS out of adjustment, but might also be dirty throttle bodies. Check the TPS voltage at idle first, and if it's still OK, check the throttle bodies for carbon and gunk buildup which can make them stick slightly before moving off idle. If it's really gunked up, the gunk will actually prevent air from getting into the engine just off idle, and will cause the same problem. Good luck!
Thanks for the cruise control DIY. Didn't even occur to me about the cancel switch on the brake. Drive shaft has been put on hold until the Celica gets back from the shop. Looks like it could be a big job if I start to get carried away. Decided to throw the clock and put something cool and modern in it's place, ie. USB or something. Throttle bodies were removed and polished clean (polished may be a bit exaggerated) about 6 months ago, so I'm guessing probably TPS. I will check this.
