I've noticed that my car runs about 160 while driving. It is a 92 with a 305 TPI. If you sit in traffic it will run up to about 220 but you'll see the needle start to drop and I'm guessing that is the thermostat kicking in. The issue I have is the car is running a little too rich. I was told by one person that it is the cats causing it. I dont get it. If the car is running 160 driving down the road then how can it heat up and lean out? Part of me is thinking a full tune up, plugs, wires, rotor and coil. But another part thinks maybe it is a thermostat issue.

 

 

I agree with NINA, you're running too cool and the car isn't ever really "warming up". Get a 180 T-stat or a factory 195. I run a 180 in my 84 T/A with mild build 355 and it hardly ever goes over the first tick on the gauge at highway speeds. In town it'll run up till the fans kick on then cool back down to the first tick mark again. Also, going by when the fan's kick on, assuming the fan switch is more accurate than my gauge, the temp gauge is about 20* off (reads hotter).

 

I run t-statless and an aluminum rad, and the car seems to run fine. I did read something about removing your air injection system making the car run leaner, I'm almost positive it's true since my mpgs went up, but I would also say try a 180 t-stat since they are cheap.

 

Can anyone elaborate on removal of the air injection? My car runs a tad rich and I wonder if this could be the equalizer. BTW, I did put in a stock 195 t-stat last weekend. It runs the same. I guess it is normal. From what I've been reading our stock gauges are not the best. I've also read about a coolant bypass trick. Anyone know about that?

 

there are a few ways to go about doing it, there are delete pulleys or you can bypass the a/c and smog pump like I did with a shorter belt and a grooved idler pulley...I really should take pics of it...

 

If your car runs a tad rich, it needs to be tuned. Removing that AIR system won't fix that though it may cure the "Symptom" of running rich.

The AIR system injects semi-burnt exhust back into the intake to be "re-burnt", to help with emissions. If you have an emissions test where you are, you can't remove it because it's an automatic "fail" on the visual test.

 

We just have the breather up here, no visual, and it passes perfectly fine. Given it does have a relatively new cat, but the people who had the car before me put on a generic cat and didn't hook up the air to the cat because they couldn't. Air is mainly for when the car is cold anyway.

 

mine does the same thing but i got a new thermostat, it is on the left side of the temp gauge till i wait for a bit. then it starts to rise high, then when i start to drive it kicks back to 160ish.. now keep in mind i got a new thermostat, radiator. only thing i HAVENT done is flush my system so im probably gonna have too soon.

 

Have you ever looked under the car, that huge plastic/rubber airdam is why your car cools so fast when you drive. Thirdgens are great bottom breathers, and im my mind there is no such thing as too cool.

 

I hope you don't have the same problem as me, I ran the car with a hose in the radiator to flush it, and did so until all the fluids coming out were clear. I put in my new radiator and about a week later I checked it and it was still rusty...I have no idea what the problem is.

 

probably rust from deep inside the engine. before i got my car running after its deep slumber i put a hose through the system and tried to clean it up then put my new radiator, then after i put fluid and what not, i got the car running and it came out all rusty, this was because water didnt reach to where the real rust was at, hopefully when i do flush though the rust i clean away wont open new problems/

 

I have no real back story on my car other than it was totaled, front end was demolished. my doors are slightly bowed outward and a lot of components up front are fairly new. They guy I got it from said he found it in a tow yard, so either my rust built up while it was in the tow yard or they swapped in a junker engine and slapped my car back together half assedly...I'm thinking it's the latter of the 2. I might shove a pressure washer up through the water pump holes when I replace it, I've already got bearing squeek on it.

 

Just curious but how do you know its running too rich? My 91Z runs about 170 while going down the road(180 degree thermostat) so I wouldn't be worried about it running too cool.

I have also done the coolant bypass mod. All you are doing is bypassing the coolant lines that go to the throttle body, its good for a very small amount of power. You don't need to heat the throttle body unless you drive your car in extremly cold conditions. In warm weather it heats the incoming air even more and you loose a small amount of power.

 

Pray that your freeze(frost) plugs dont start leaking when you flush all that crap out, I know mine did when i redid the heads and cam. I flushed the motor out very good, then once i started it up again, I needed to replace the freeze plugs. Heres a tip, if you ever get the engine that bare like i did, just replace the freeze plugs while your there.

 

Not quite. But as long as it passes the sniffer and you don't have any visual, you'll be fine. The air works at part throttle, cycles some of the exhaust so you reburn it to get cleaner emissions. Has nothing to do when it's "cold".

 

Ok. So just remove and cap the cooling line going to the throttle body then. Here we have the sniffer test. It needs new cats as the nox readings were high but within limits. He said that could be the cause if the rich condition. I was also told to have the original chip reprogrammed to remove the restrictions. I don't want to go nuts but do want to do whatever I can to help it run better. I was going off the gauge but being new to third gens I was schooled on how they operate. Looking to get a lower fan switch soon.

 

Catalytic converters are much better than the were 20 years ago, so there really isn't a need to reburn the exhaust.