86 fiero thermostat and exhaust problem

If you need to flush the core you would be better to change it. It would get flushed when you flush the entire system. Also try changing you thermostat that is the usual first cause of running hot or a bad water pump. Good Luck!

You will need to remove your air cleaner and duct assembly. You will then see the thermostat housing sandwiched between the back of the intake manifold and the exhaust crossover pipe. The service manual says to remove the exhaust crossover pipe, but trust me, you do not want to attempt this unless you have access to a torch to heat the nuts that hold the thing to the exhaust manifolds. If you break a stud, then you are going to be removing an exhaust manifold for broken stud removal. If you take the 8mm screws out of the heat shield on the exhaust crossover pipe, you can wiggle the heat shield out. This will provide enough room to get the lower thermostat housing bolt out. It is a pain to do it this way, but it works and will prevent broken exhaust pipe studs. Sometimes the little 8mm bolts will also break, but since they only hold the heat shield, it is of no great consequence.

Then all you have to do is remove the two bolts that hold the thermostat housing to the manifold. The thermostat is directly under it.
Then the only other real "trick" is getting the thermostat and O-ring to stay in the correct position while you put the thermostat bolts back in. A trick that I use is a small wooden wedge. I put the thermostat housing into place over the thermostat and O-ring, then place mt wedge between the thermostat housing and the crossover pipe to hold the thermostat housing in place while I start the bolts. Otherwise, the thermostat tends to slide out the bottom while you are trying to get the bolts started.

Let me know how it goes...

Replace the radiator. It is most likely clogged due to age.

I would drain and replace the gas, old gas will cause this sort of problem.

If you have already changed the gas, first you need to check the fuel pressure, there is a location the fuel rail to attach a gauge (looks like a a/c refill fitting)

If you have good gas pressure, you likely have 1 or more clogged injectors, you can try and clean them, or simply swap them out.

A good source for parts is fierostore .com

Hope this helps.

look around the exhaust manifold there is a wire that has melted and it is shorting out hope this helps you tape it up and pull it away from the exhaust with a zip tie so it dont happen any more

Jack up car.
Remove tires on back.
Remove Nut on top of each strut, located inside engine hatch.
Remove lower bolts from spindle.
Remove strut.
Use spring compressor to remove springs.
Reverse procedure to replace.

Replace it. Not a difficult job. Be careful the bracket on the V6 4spd. isn't strong so don't break it while loosening the slave cylinder retaining nuts.

Good luck,

Rebel Faggioli

the brain is not sending the proper fuel pressure codes to the fuel rail to evenly distribute the fuel to the intake and fuel rail.
perform a fuel pressure test check on it ok? also run a diagnostic scan on it and see what codes come out.

well fieros are very different cars you need to fill collent in a speical way so air doesnt get in the lines most fiero owners do not know this but it very important The best way to tell it is for wikipedia
Cooling system issues
With an already hot normal operating temperature of 220 °F (104 °C) prior to the recall switching to a 195 °F (91 °C) thermostat, the mid-mounted engine utilized long pipes to carry coolant to the front-mounted radiator. This demanded that a special coolant filling procedure be followed to prevent severe overheating. Simply pouring coolant into the thermostat housing (on the engine) would leave an air bubble in the radiator, while adding coolant just to the radiator would leave an air bubble in the engine's coolant passages. Proper procedure (with engine idling and the thermostat removed, filling the thermostat housing, burping the bubble out of the radiator by cracking open the radiator cap until coolant exits) must be followed in order to ensure an air-free cooling system.
A second problem has become common as more Fieros are being serviced by shops unfamiliar with their design. The under-body coolant tubes are positioned in such a way that a casual glance beneath the car will not suggest their fragility. As a result, many have been crushed by shop lifts, resulting in a near complete lack of engine cooling. The age of the car means that even GM dealerships may now be unaware of the proper jacking methods.
Lastly, the absence of a spare tire (at the front of the car, right behind the radiator) could have an effect on coolant system performance. i dont know who wrote this and i dont take credit for it

follow top radatior hose or lower it should be a housen with two bolts