Issues with my '86 Toyota MR2

So, I just recently bought this car earlier this year and it’s always seemed to be giving me problems. One of the major ones is that the engine is always dying. When it first did this a couple times after I bought it, my dad and I assumed it was the alternator(we figured it couldn’t be the battery because the battery that was in it was relatively new, but we took it to Auto Zone to check the volts on it anyways, and it was all good; we did get the alternator checked also and the guy said it was the alternator), so, we bought a new alternator and my dad and I replaced it. About a week or two later, it started back up with the issue. Whether I was stopped at a red light, slowing down, or making a turn, the engine would die. So, whenever I’m at a red light, I’ll put the E-brakes on or put the car in neutral and just get the RPMs up, but shortly after I rev it up, it’ll stall. And I try pushing the clutch in all the way, majority of the time, it doesn’t make a difference and dies anyway. Would anyone have an idea of what the problem might be?

Thank you!

'86 MR2? Sweet.
But also old. That means the problem could be anywhere. AZ is not the proper place to take this. You’ll need a good shop that can hook up a scope to thoroughly check out the ignition system, hook up the fittings to test the fuel pressure, and unless I miss my guess this is carbureted, so you’ll need someone versed in carburetors.

My wild guess is that you’ll end up finding the problem in the float bowl… but let the shop do its job and diagnose it properly. I can’t do that from here.

This probably has a 4A-GE engine which is fuel injected. Typically this problem you are having is due either to a stuck idle air control (IAC) motor or an idle position switch (IPS) not making. The IPS tells the computer when your foot is off the gas and then the computer controls the idle speed through the IAC.

The IPS is part of the TPS (throttle position sensor) attached to the end of the throttle plate in the throttle body. The throttle cable is on the other side of the same shaft. The IAC is in the side of the throttle body. Sometimes a good throttle body cleaning can fix this issue.

Yeah, I’ve thought about taking it to a Toyota dealership, but I’m not entirely sure how to even approach them. Some places around here kind of cut the opportunities for a woman to walk into a shop and get told straight up what needs done without getting scammed. I’m not fully educated with the mechanics of the car, but I know what to do if I have the information of what the issue is. Would you recommend going to a Toyota dealership?

I did a little research, and it appears Keith is 100% correct. It is fuel injected. I stand corrected.

Either way, thank you both for the help! I’ll get that checked out. :slight_smile:

Avoid a dealership. They’ll want to replace every part with any wear with brand new parts at manufacturer’s prices, which are two to three times the cost of aftermarket parts. Aftermarket parts for these cars are still readily available, and an independent shop using aftermarket parts will save you a boatload of money.

I’ll keep that in mind. I’ll probably just ask around different local shops what they think. Do you think I’m going to need parts?

At 29 years old I’d be surprised if your car DIDN’T need some parts.
It’s a great car, though, and if it’s in decent shape it’s worth keeping up. The MR2s are almost a cult car, with a subculture all their own. They’re among the handful of affordable runabout sports cars that can remind us of what driving used to be about.

True, although, I know a little bit about the history of the car, and I know it was well taken care of. But would you have any clue what I would have to do if what all Keith explained is correct?

“Sometimes a good throttle body cleaning can fix this issue.” - Keith.

That’s the best advice you can get without actually looking at the engine. Throttle bodies have a number of mechanical parts that can wear over time, such as shafts that can wear grooves in them and begin to stick. And rubber parts such as vacuum tubes and O-rings that can dry up and shrink over 29 years, allowing leakage that can cause idling malfunctions.

It could be almost anything, a car of that vintage. But what I’d check first is the idle rpm. Does it meet the spec? If not, ask a shop to adjust it. Engine of that vintage often had an idle air bleed screw. You just turn it until the idle speed matches what it should be. On some cars you have to set the engine computer to open loop mode first by making a jumper connection at the test connector.

Why would the idle speed need to be adjusted? B/c the throttle body clogs up over time, and less air gets through at idle than when the engine was new. This causes the idle speed to drop.

Another simple thing to check is vacuum leaks. Lots of vacuum hoses and fittings that can break, crack, harden, etc.

Id clean the throttle Body with some carb spray and a rag… then also clean the MAF sensor with the same spray… Then look into exactly what Keith mentioned. It wouldnt hurt to also replace the fuel filter as well…who know the last time it was replaced.

MR2’s are SO MUCH FUN… I’ve had 2 over the yrs… Being a mechanic helps but these are pretty reliable vehicles. The MR2 is by all measure now a Cult Car…Guys are out there who eat sleep and Dream all things MR2…Why not visit a few of those websites and get the Skinny on every single item that fails and the symptoms they produce? Im a little curious as to how one buys a 1st Gen MR2 nowadays and is not already part of the Cult… You must have bought this little gem for some reason… I love them and when you fix the few small issues yours has you will love it also.


If there is an igniter under the ignition coil, you can suspect that too. Check plug wires and make sure coil wire is pushed in all the way.

If it was the ignitor it probably wouldnt run…or would run and shut off and stay off. This is a low idle/stalling issue

I left out that the previous owner installed a new engine after 200K. I love this car, I just haven’t had the chance invest some time and work into it.

Unless he changed the ECU along with the engine, it may need to be remapped. It’s entirely possible that the ECU simply isn’t providing the correct metering.

I’d be inclined to start by getting the serial number off the engine, stopping by the dealers to have the parts guy look it up and see if the prior owner put in a different year, and also requesting a printout of the protocol for programming the ECU.

If the engine was from same year same model…and NOT from a JDM source…she would be OK… However there are too many variables at stake when you do an engine swap and dont do the homework Prior to that engine swapage. You would THINK the guy doing the swap did his homework…but I have very little faith in anyone else spinning wrenches but me…aside from the guys that I know (who know their S&^t) Most people who are self declared “Mechanics” are Anything but.

Sad but true…Jeez the things I have seen done out there that I had to correct. While I would be enlisted to correct their massive mistakes I would be asking out loud "Didn’t you look this up prior? What made you think you could?.. or my fav "WTF were you thinking here? " Either guys are just too lazy, dont know, or think it doesnt matter…I dunno what.

Mtn Bike brings up a good point… I PRAY the engine swapper did his homework prior to this swap…because it really does matter. Simple enough to look it all up… Look for engine number…and figure out what is in there now…the VIN will tell you what was in the engine bay…and hopefully they match up… There could be one or more wire swaps that are needed if the engine came straight from Japan…or if they jumped years in engine mfg… They change silly things sometimes…for whatever reason. So this is important info here…as no mechanical work will solve an issue in the engine running dept when a few wires in the harness are swapped or not correct due to year swapping an engine for example…could be a simple matter of moving one pin to another in the harness and Voila! It then runs perfectly. All good things to know here…


With a car like this, there should be a forum out there for these cars that fits your needs. I did a quick google search and saw a couple, but I was not impressed with any of the ones I checked. You should do a google search for “mr2 forum” or “toyota mr2 forum” and start checking them out.

A good active forum can give you specific information related to this vehicle, and some of the quirks and easy fixes that are unique to it. I belong to a forum for the Tercel 4wd Wagon. Only about 2000 of these were ever built, yet this has a very active forum with about 20 posts per day.