No Check Engine Light

I have a 91 MR2 Turbo. It is not running well. When I press on the gas very hard and my boost passes 5psi it fells like someone just let off the gas petal and I will not receive power again until I let off the gas. I took it to the Toyota dealership and they said I have a cracked manifold. Also the pointed out that I am missing my check engine light and they cannot pull engine codes. Why would some one remove the check engine light and how do I hook up a new one. Where is it running from? Also how hard is it to replace the manifold?

The only reason someone would have removed the check engine light is to sell a car with the light lit (i.e. problems).

Chances are you just need a new check engine light bulb. It is a bit of a challenge to get to it.

You need it to check codes though. See here:
http://www.automotiveforums.com/vbulletin/showthread.php?p=2528958

As for the manifold, it depends on which one it is (exhaust or intake).

I would be willing to bet you have at least Code 52 (the knock sensor). That would cause your running issues.

If you just bought the car, I would suggest:
1. Replacing the check engine bulb
2. Buying new ignition pieces (TOYOTA cap, rotor, wires and plugs)
3. I would be prepared to need a new knock sensor. They are a bit over $100 but EASY to install. You can do this yourself with only a jack and a 27mm socket.

Thanks for the info. I took most of the gage cluster apart I've still have not disconnected it. Looks like I will need to disconnect the Speedometer cable from under the car to give enough slack to pull the cluster out to check the bulb. I will do that tomorrow.

They guys at Toyota took my 89.00 dollars to check out the car but they said they could do nothing until they could make the check engine like work. They said they had no idea how to take the dash apart because they had never done it before. They said it would be no less than four hours labor. I have most of it taken apart and it only took me 45 minutes and I've never done it before and have no info on how to do it. I have a feeling they are lying to me about my car in several different areas. They said the turbo is leaking oil and needs to be replaced for 2400.00 dollars. For that much I would rather have an aftermarket turbo. For now it seems to function other than the cutting the power out at 3k rpm. I will see what the engine codes are after I fix the c.e.l.

What do you guys think about buying the J-spec engines with 225-245hp? The guy at Toyota auto shop said they are garbage and that the engines are never taken care of because people know they are just going to remove the engine after 40k miles any way. Again I think they guy is full of crap. What do you guys think is it a good idea to replace the engine and turbo with one from Japan? Or do you think I should pay the 2400 for the turbo and keep the engine in my car with 110k miles? Thanks again.

110,000 miles thats nothing on a Mr2... i'd say keep the car and buy an aftermarket turbo perferably the td06 from greddy awsome kit for under 2g's. But its your choice. Oh and by the way i dont know if you live in california or not but the jdm motor does not have a knock sensor and also does not come with an egr valve, therefore will not smog.

Well I live in Vancouver WA and I still do need to pass DEQ or smog test but it's not as strict as CA. Why would the engines not come with a knock sensor? Isnt this important with a turbo? I thought all newer engines came with them. Are the engines a direct bolt it using the previous engine? Or will I still need other parts?

How about this engine?
http://www.totaljdm.com/index.cfm/fuseaction/engines.displayengine/item_num/JDMTOYOTA3SGTEM/jdm_engines.htm
It says it's out of 94-98 MR2 will that work in my 91? I figure why not put in an newer engine for 1800 then spend 2k on just the turbo. Is this sound reasoning?

Also my exhaust manifold is cracked, warped, or is just leaking around the gasket. Dont really know how to tell but that is what Toyota said.

Hi FXR

Sorry to hear about your car....

I wouldn`t bother going back to that toyota dealership. 4 hrs to take the meter out!! I could do in 15 mins!! Call themselves mechanics!! More like Monkeys!!

Changing the manifold whilst with the engine still in the car is a major pain. Any garage you ask to do this will charge you bigtime even if they are honest. I wouldn`t attempt to try it yourself as them manifold bolts can shear off when undoing. If you do get it done make sure that the garage replaces all the bolts for new items.

If you can afford it go for the later engine/gearbox/electrics swap. You`ll get the extra power, fuel cut isn`t as low as early engines and the later engines use an airflow sensor and not airflow meter. The sensor type isn`t as restrictive when it comes to upping the power. Low 300bhp is achievable without major mods. Earlier engines will need a lot of money to be spent for that sort of power to be achieved safely.

Try and pull the meter out as far as you can, use your hand to feel tha cable and unplug. Undoing the cable from the engine bay isn`t going to help much.

If you need anymore advice you can email me and I`ll try and get back to you as soon as I can.

You can get the speedo cable off at the dash ... there is not a lot of wiggle room, but it can be done. A gentle tug may give you some more slack.

I would not consider an engien swap until you diagnos what is wrong ... this really could be something simple.

$2400 for a new turbo is typical from Toyota and there are MUCH better options out there.

110,000 miles thats nothing on a Mr2...
... depending on how they were maintained.

i'd say keep the car and buy an aftermarket turbo perferably the td06 from greddy awsome kit for under 2g's.
The TD06 is an awesome kit, I would not say it is "prefered."

the jdm motor does not have a knock sensor and also does not come with an egr valve, therefore will not smog.
The JDM motor has the knock sensor.
Regardless, the knock sensor has nothing to do with smog.

I vote no on the GenIII JDM engines as they are not worth the extra dollars they command on the market in my opinion.

At this point, I would say fix your check engine light, figure out what is wrong and go from there.

There is no sense in building a new home if only the front door is broken.

Okay thanks for the additional information I found that the light bulb had fallen out and was sitting behind the gauge cluster it was also burned out. I replaced it and the light worked fine here are the codes I received.

21 Oxygen Sensor/Heater cct Detection of oxygen sensor deterioration or open or short in oxygen sensor heater.

22 Water Temp Signal Open or short in water temp. sensor signal (THW).

25 Air-fuel Ratio Lean Malfunction Oxygen sensor outputs a lean signal continuously for several seconds during air-fuel ratio correction. Open or short in oxygen sensor (OX).

26 Air-fuel Ratio Rich Malfunction Oxygen sensor outputs a rich signal continuously for several seconds during air-fuel ratio correction.

34 Turbo charging Pressure Signal Fuel cut-off due to high turbo charging pressure.

43 Starter Signal No STA signal to ECU until engine speed reaches 800rpm with vehicle not moving.

__________________________________________________ ______

21. Okay O2 sensor not working = makes sense I will replace it.
22. Water temp. This makes sense I don’t think the thermostat is working because it takes forever for the heater to get warm and the water gauge works but will never go above the C if your not idling the engine. This would make the computer freak out I'm sure.
25 and 26 I'm guessing are because of the O2 sensor.
34 This sounds like my problem because the fuel feels like it is getting cut whenever there is more than just a few psi of boost.
43. Does this have something to do with the fact that the car idles at 800 rpm even when you first start it in the morning?

I'm trying to understand what you mean here.

"I vote no on the GenIII JDM engines as they are not worth the extra dollars they command on the market in my opinion."

I found the JDM's to be around 1800.00 for engine, turbo, and trans. That is less than the turbo by itself. So do you mean the cost would be in gathering the parts to make it work? I'm sorry but I'm just trying to understand how all this works I'm new at it thanks.

There are two water temp sensors. One of the gauge and one for the ECU.

If it were my car, I would:
1. Buy new ignition pieces (TOYOTA cap, rotor, wires and plugs)
2. Buy a new thermostat
3. Flush/fill coolant
4. oil change and fuel filter
5. CLEAR CODES

See what codes come back.
Chances are you are going to need an O2 sensor and a water temp sensor for the ECU.

I would see where that gets you.
It sounds to me like your car just needs some TLC and regular maintenance that has been neglected.

As for engines, not all JDM engines have the extra power. It has to be the GenIIIs.
In order for you to get this engine in your car, you will need the ECU, wiring harness and engine. It would be wise to get the tranny and axles as well.
Most people who go for GenIIIs are paying well over $2K for a rear clip and then labor on top of that to get it swapped over.

For that much $$$, I could get what you already have into the 12s :D

2400 from toyota for a turbo sounds about right.

i wouldn't go back to them though cause they sound pretty useless.

why do they need the light? don't toyota use their diagnosis gear hooked up to the plug on the car? isn't that what its for? i thought the light was just a back up for us poor bastards without the big toys.

go somewhere else before you bother getting the turbo replaced. as Jeckyl said it could be something really simple, and even if it's not, wouldn't it be better to get the problem sorted before replacing the turbo and getting into all the assosciated confusion?

if the turbo is leaking oil inside it CAN be rebuilt and have the seals replaced. i remember i saw someone that could do it for hundreds not thousands... sorry can't remember where though.

sounds like toyota don't really want your business.

This website discribes my problem exactly.

http://www.mrcontrols.com/primers/fuelCut.htm

Only my car does a fuel cut at about 0-5 psi or around 3000-3500 rpm.

Is it posible that my manifold pressure sensor is thinking 4.2 volts at a lower boost pressure? If so do I ask Toyota for a "Manifold Pressure Sensor"? Is that what it is called? They are not to bright and I dont want to confuse them anymore than I already have.

do you have an air filter that you have to oil?

Nope

FXRseen, if you want to "test" to see if you are hitting fuel cut, simply CORK the vac line going to the MAP sensor. Then drive the car and try to boost ... you will have NO fuel cut (you disconneceted it).

Be careful of how far you are boosting.
If your problem goes away, then it was the MAP sensor. If it is still there, it is something else.

KEEP The MAP sensor plugged in electrically though!
Just cork the vac line.

Okay I'll try the corking the vac line if the rest of what I tried doesn’t work. I work most the day so its not fun to work on this car in the dark, raining and in the drive way. So I'm going to wait until Saturday to finish.

But this is what I've done so far this week to get the car on the way to running better. I've replaced the O2 sensor. The one that was on there was clearly dead with no gasket and I was able to unscrew it with my fingers. I've replaced the burnt out light bulbs in the gauge cluster and attached wire harnesses that have been disconnected by the previous owner when they were trying to do some interior mods (stupid kids). Mostly the cigarette lighter and gauge potentiometer.

I was going to replace the thermostat because the water never gets up to temp. I've never done this on a MR2 but I own a Fiero and I would imagine it's the same process. So I pop the hood and look around under the radiator for a drain only to not find one. Come to find out its on top of the radiator. Could they have a different Toyota radiator upside-down that just happens to match the MR2's hose configuration? So I'm saving the replacement of the Thermostat for Saturday when I can see better.

Here's a good read for you:
http://www.mr2-tech.com/bgb/mechanical/volume1/cooling_system.htm

interesting topic. Gen III or rebuild? that is the ultimate question. then Gen II's are cheap. and easy to swap. i am doing the work myself and my US motor has compression of 75 and 85 cyl num 2 and 3 respectively. the motor is out of the car and on the floor. i dont know what to do or get.
i could get a gen III for 1200 motor only. i could use my harness and ECU to make it work but not to full potential.
there is another for 1800 motor trans and harness for 1800 just need the ECU.
i could get a rear clip gen III for 1900 bucks straight from japan. it will just take around two months.

i could rebuild the one i have for aprox 4000 bucks. but it will be brand new and blueprinted. take about three months and still need power upgrades. i dont think i can on my budget

so what should i do ...when i have no car at the moment and need to get around soon.