| Accidents |
In short, you more than likely have air bubbles in your cooling system that must come out. These air bubbles cause the temp gauge to spike since steam is much hotter than water. The reason for the idle bounce is that the air bubbles go past the idle throttle temperature adjustment. Read Tim Kinginsbuy's excellent FAQ on the temp gauge problem: There is also one other thing that will cause an idle to bounce.
Sometimes if the idle has been incorrectly adjusted too high, the ECU will
make the idle bounce as it tries in vain to lower the rpm. Just manually
adjust the idle down to 800rpm once the engine is fully warm, and this
should go away.
88-89 weak AC: Due to customer complaints, it was rumored that Toyota in the 88-89
model years lessened the load that the AC puts on the engine thus making
less cold air.
Trouble Codes:
1. Find the service connector (a little black box, about 1" square near air flow meter). Open it. Short terminals marked T and E1 with a wire. 2. Turn all accessories, especially A/C off. Put the ignition key in ON position. Stare at the "CHECK Engine" light (amber light on the dash). Count the number of times it blinks in 5 seconds. 3. The codes are: Number of Blinks: Code: 1 Normal
Now, the above codes are not a gospel truth. Often the computer will
decide something is wrong when it is not, and it will point to the wrong
sensor. But it's a start. The code will run the light continuously with
2.5 second intervals between the series of pulses, i.e. 5 blinks, 2.5 seconds
of nothing, 5 blinks, 2.5 sec..... for O2 sensor. To stop the insanity,
remove the jumper between T and E1. I highly recommend to do a check, record
the problems, remove the AM2 fuse for 30 seconds (that will cancel the
codes in memory) and drive around for a week. Check them again. That way
any old code will be canceled and the second reading might point to the
actual problem. BTW, if ECU thinks there are multiple problems, it'll give
you more than one code, just keep counting
Starter Run-on: Another pretty common problem with older MKI's is the starter will run
on. The solenoid in the starter sticks thus causing the problem. You can
either spring for a new Toyota starter or get a quality rebuild shop to
rebuild it. It is usually not recommended to buy the generic hundred dollar
"lifetime guarantee" starters as you will often have a lifetime of replacing
them.
Oil Leaks: Out of my many many years of owning AW11s, this is one of the problems that bugs me to no end. Sometimes you can get lucky, and the oil leak is coming from one of the easy to find sources like valve covers, or from the external distributor o-ring. But other times, you can chase this problem for years and never solve the problem. All I can say is good luck. One of the more common things to do is to first replace the external distributor O-ring. It will harden over time and let oil through. Also the valve cover bolts are known to work their way loose, and just need to be tightened. The oil cooler lines are also one of the more common leak points. Here is a list of known MKI Mr2 oil leak locations: 1) Cam cover nuts and/or hard valve cover gaskets
Some of the less common leaks are from an oil filter that is loose, and the front & rear main seals. The distributor shaft seal leak can be fixed, but the seal itself cannot
be sourced from Toyota. To get to this seal you have to take apart
the distributor. You will have to more than likely carefully drill
out the pin that holds gear in place, and then carefully tap off the gear.
(few have luck pressing out the pin) Then slide the shaft out and
you can see a bearing and seal on the shaft. The seal can be sourced
from larger bearing supply companies. It is a 20mm OD x 10mm ID x
5mm thick, double lip, spring seal. (Its reported that the 7mm thick
seal works fine as well) You will then have to either find a new
press pin for the gear (4mm x16mm roll pin), or you can order a new gear
and pin from Toyota as they do stock these two things.
Clutch Hydraulics: It is a well known problem not only on Mr2s but Toyotas in general, that the clutch hydraulics have a tendency to leak after getting old. While many have a problem with a leaky master cylinder, others will have a problem with the slave cylinder. (mounted on the transmission) Most have a problem with both. When one starts to go, you can usually bet that the other one doesn't have much life left in it. Most owners first find out about this problem when they get in their car one day and press the pedal to the floor only to find no resistance and a shifter that wont go into gear. Usually this can be quickly overcome by a few pedal pumps to get the fluid somewhat pressurized, but you can bet that a replacement will soon be needed. In addition to this, when the master cylinder goes, it will usually leak both in the front trunk and the passenger compartment under the carpet. As a result the leaking fluid will eat away the paint on all the surfaces that it comes into contact with. Be sure to clean this up when replacing the master cylinder. While some have luck with the rebuild kits, many do not, and thus spring
for a new part. When bleeding the system out, putting in high-temp
brake fluid will give you some assurance that the fluid will not boil on
hot summer days, thus avoiding a spongy or nonexistent clutch pedal.
Clutch Replacement and Engine Removal information: While not the easiest job in the world, it is something that can be down with only a few special tools needed. The first article is info given to us on a clutch only replacement. After doing the job myself, I can pretty much agree with everything that is said there. The second article is the story of my engine service project on my 87 NA. I dropped the engine to not only replace the clutch, but also to do some work on the engine. Hopefully these two articles will let one know what they are getting into when doing this job. The worst part of a clutch job BY FAR is trying to get the transaxle back onto the crankshaft. While many struggle with transmission jacks, I found that while somewhat of an overkill, an engine hoist works perfect to hold the transaxle in the air while you try to jiggle it back onto the engine. Another alternative taken by some to install come-alongs into ceiling trusses to hold/lower/raise the engine and/or transaxle. Clutch Notes and Engine Removal and Servicing
Timing Belt Replacement It is suggested by Toyota to replace the timing belt every 60k miles. However this is a job that is not enjoyed by many thus causing procrastination for replacement. As a result many have found the 60k mile recommendation to be slightly conservative as some have had T-belts last in upwards of 100k. The engine is also a non-interference design meaning that if the belt does break, the valves will not bash into the pistons. Nevertheless, regular T-belt replacement is a good practice to get into as this will keep one from breaking down at the worst possible time, something T-belts seem to do. So do you want to save some dough and replace it yourself, or do you want to take your chances with your local toyota dealer? If you go the dealer route, be sure to look in advance to see whether or not your local dealer or local import specialist runs T-belt specials. It is common practice for many Toyota dealers and import repair shops to have $150-$250 specials to drum up business. However if you do go a to dealer, it is suggested to be very careful in choosing one as Toyota is often not known for its customer service. While some get lucky in that their local dealer happens to be a good one, for many this is not the case. This is even more true when it comes to the Mr2 as many dealers have limited experience with them. This can be further proved as sometimes the dealer will exclude Mr2s from their T-belt specials as they either feel it takes longer to do the Mr2 vs other Toyotas (not really) or they are scared to work on the car. If you plan to do this yourself, a little patience and some good tools go a long way. A BGB (Big Green Book, nickname for the service manual) is a must. Set aside a weekend if this is your first time to ensure that you get it done, and plan ahead. Also be very sure that the belt is lined up on the correct teeth. In doing the job yourself, you can save some cash, but more importantly you will feel good in knowing the job was done right. A search through the Mr2 mailing list archive will once again give more detailed info. The biggest problem that you will face if you do this job yourself is how to get the crankshaft pulley bolt off. Over the years I've heard of many different ways on how others have been able to do this. Some put the car in gear and hold the brakes while you try and get it off with a wrench. Some stick a screwdriver in the flywheel to hold the engine still. Others have had luck with sticking a wrench on the bolt, bracing the wrench on the ground and bumping the starter. I myself have never had any luck with any of those methods. So what method did I have luck with? The 750 ft-lb 3/4 inch drive wrench that I rented. Talk about power!!! The ole bolt came right off. You may have better luck with a quality 1/2 drive wrench than I did with my cheap 1/2 drive wrench, so the 3/4 drive may have been an overkill. Who knows.... Either way, plan ahead on this one, as this may ruin your day. And if you do try the other method of taking the bolt off with a wrench and breaker bar while somehow holding the crank still, don't pull your back, and try not to break too many tools! :) The second biggest problem you may face is how to get the crank pulley off once the bolt has been removed. While sometimes the pulley will come off by pulling on it, the fit is usually too tight, and another method must be used. A very few have luck trying to pry it off with a large screw driver, but this is not recommended. You can easily chip, and/or break the pulley this way. The best method is to use a cheap puller that can be sourced from most any auto parts store. There are two bolt holes in the pulley that you screw into with the puller. There is very little room to work with, but when using the right puller, there is just enough room to get it off. A common question that comes up when replacing the T-belt is what else
can be replaced while you have everything off? The answer to this
question is the idler pulley and the water pump. Both are but a few
bolts away from replacement once the T-belt is off, and both run approx.
~$70 from Toyota. So do you need to replace them? Most all
AW11 are over 100k miles these days, and if you still have the stock ones
in and the budget allows it, the author along with others on the Mr2 list
would recommend replacing them. Doing so will enhance the reliability of
the car, as both can fail although it is not that often of an occurrence.
First check the idler pulley to see how well it spins when turned.
If any scratching noises are heard or non symmetrical rotation witnessed,
consider your self lucky that it has not already seized up. If it
spins fine the decision is up to you. For the water pump check to
see how much play the impeller has and make a decision from there.
Once again as stated above, it is not that common for these two things
to fail, but it does happen, and if you do replace them, you can consider
this cheap insurance vs breaking down on the side of the road late at night.
Passing smog: In general, a well cared for MKI will often pass smog checks with flying colors, as the 4A engine is a very well designed and very efficient engine. But in the case that yours is not in good shape, and will not pass smog inspection, David Kucharczyk, offers the following information to help pass your car, and get it back on the road: Smoke on start up: As a general rule, white smoke on start up means water in the combustion
chamber, while blue smoke means oil in the chamber. Often this is due to
a blown head gasket, but not always. Sometimes blue smoke is due to the
valve guides leaking, which is another common occurrence, often after many
miles however.
Cracked Exhaust Manifold: A problem that appears mostly on the 85 and 86 Mr2s. If you have
this problem, the crack will very likely be found right by the #4 piston.
This was supposedly fixed in the 87 cars as a different metal is used in
the manifolds. While welding up the crack is often a common fix,
this most times is only a temporary fix as the crack will often find its
way back. New replacement manifolds have shown to be much less prone
to this cracking.
Transmission syncro wear and the infamous 5th gear popout The 85-86 Mr2 had the C-50 transmission while the 87+ NA models had
the C-52, which was an upgraded and strengthened version of the C-50.
This included stronger input and output shafts with larger diameter bearings
on some of the
Having rebuilt several C-50/C-52's I think I have a pretty good idea what causes the 5th gear pop-out problem, and how to fix it.
For some reason, when Toyota designed the electrical system for the AW11 the system was wired so that when the alternator is about to go bad, the Charge, Cooling Fan, and Brake light will light up on the dash. Sometimes it will only come on intermittently, and then will stay on all the time. Sometimes it just comes on out of the blue and stays on. Either way, the chances are that the alternator doesn't have much life left in it. While it is usually recommended to buy new Toyota parts at all costs, this is not always the case when it comes to alternators. Most local alternator rebuild shops are pretty good, and can usually rebuild a Toyota alternator for around $100. I along with many others have done this on many different MR2s, and have had no problems. For those with NAs, the alternator can be installed/uninstalled from
the top of the car. Just take out the coolant overflow tank, and
unbolt the top bracket from the engine, unbolt the wires and mounting bolts,
and out it comes. For those with an SC, the change out is not as
easy, as the alternator is on the exhaust side.
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