86 2.8 5speed running rich (Page 1/1) willyt AUG 17, 03:03 PM Hi all, I recently changed my spark plugs and found them to have a lot of soot on them, and my exhaust smells very rich. The previous owner installed a 160 or 180 degree thermostat on the car, which I am planning on replacing with a 195. I thought it was common to install a 160 thermostat with a “performance chip” I was wondering how to tell if I have such a chip installed on my car. Thanks for all the help. willyt AUG 17, 04:41 PM Also - if i do happen to have a performance chip installed, can I just remove it, or do I need a stock part to put in its place? willyt AUG 17, 06:05 PM Well it looks like I have the stock chip, but I do still have a 180 degree thermostat and a lower temp fan switch. My car never heats up above 185 even on a 95 degree day. Would this cause the car to run rich enough to foul spark plugs? Patrick AUG 17, 07:28 PM quote Originally posted by willyt: My car never heats up above 185 even on a 95 degree day. What are you basing that on... the gauge reading? If so, just be aware that the Fiero's temperature gauge is notoriously inaccurate. It would be invaluable for you to get a scanner reading of what temperature is actually being reported to the ECU, both by the CTS and by the MAT. If the readings are too low, the ECU believes the engine is cold and richens the air/fuel mixture. No matter what, replacing your 180° thermostat with the proper 195° one is a good idea. The best one to buy bar none is the Stant SuperStat 45819. willyt AUG 17, 07:31 PM I agree the temp gauge may not be accurate, but I did put a 195 degree thermostat in it for an afternoon, shot up to around 200 degrees which scared me at the time because it was so much hotter than it used to run. After some research I found that I need to swap the 195 degree back in, ive just been fighting fouled plugs as well and was curious if this could be my whole issue or if I should keep looking. Thanks for the help!! Patrick AUG 17, 07:42 PM quote Originally posted by willyt: ...I did put a 195 degree thermostat in it for an afternoon, shot up to around 200 degrees which scared me at the time because it was so much hotter than it used to run. Yet, you don't like "soot" on your plugs. You're difficult to please. As you may or may not be aware, the factory fan switch doesn't kick in until the coolant hits 235°... so 200°, if accurate, is nothing to be concerned with. I don't know which "low temperature" fan switch you have, but a lot of us use Rodney Dickman's 210° on and 200° off fan switch along with a 195° thermostat. Works great. willyt AUG 17, 07:47 PM I’m not sure what temp fan switch I have but I know its on when I park the car so it must be running at 180