I drove my car over 100 miles today, half of that on the highway. Why is it that when the temp gauge is 1/8" to the left (colder) side of the 220 degree mark, the car has lost a LOT of it's power, bogs down horribly, and generally acts like its overheating?

The car is only happy right or just over 160 degrees...

Whats the deal?

 

Did you put a 160* thermostat in it? And have you checked for any codes that were set by the ECM?

If the engine isn't getting warm enough, it'll stay in open-loop mode. This helps mask a lot of problems like the EGR, O2 sensor, EST, or something else that may not be up to snuff. Once the engine gets warm enough, the ECM works in closed-loop and that's where you're going to notice that it's running like poop and there's a problem somewhere.

Check for codes and see if there are any.

 

It's definatly not running too cold... Did you read what I typed? It has the proper thermostat too.

 

i doubt this is your problem, but as I've been playing with distributors lately, have you checked to make sure your distributor hasn't come a bit loose and messed-up your timing... also check your computer codes and make sure the oxygen sensor isn't duff -I guess that is affected by engine temperature on the exhaust if it's not working properly.... -don't try and remove the oxygen sensor if there is no problem code for it as it'll probably be ceased in the exhaust and you don't want it to snap off. When the MAF sensor filament snaps it causes those sort of symptoms, but yours has I MAP I think doesn't it -I think that's more reliable and don't know much about it but maybe check that out too??

I've probably been way off the mark, but hope it helps a little -I assume you've checked obvious stuff like bleeding/replacing the coolant...

 

Did you read what I typed?

What I'm trying to tell you is........ well first off, why do you think 160* is the magic number? I can tell you that if it is running that cool, then that's a problem. It's not supposed to (if you still have the stock EPROM). The reason I asked if you put a 160* t-stat in is a lot of people do that, then say it runs like poop.

The other reason is, why did you mention 160*? Did you use an actual thermometer in the coolant or are you going by the guage on the dash? The factory guage is nothing more than a fancy idiot light. Don't rely on it's readings as accurate.

Did you check for codes? If it's hesitating only when it's warm, it could be any of the problems I mentioned earlier. If so, there should be a code set. If not, then it could be a clogged fuel filter, clogged injector, clogged air filter, or even a vacuum leak.

I'm just telling you why you don't notice the "bog" when it's cold.

 

I didnt resond to you with an insult. I just asked you a simple question. I thought perhaps you didnt really read everything... jeesh.

Anyway I was going with 160 from the gauge in the dash... So then we know it's not acting this way because it's overheating..I'm going to check the timing tonight. The timing on our cars is vacuum advance, right?

 

Oh and I have a new O2 and MAP sensor, and a new temp sensor, air and tps sensor.... Hmm... It almost acts like the timing is being rapidly advanced and retarded... It sucks.

 

Yea..... sorry...... I deleted that.

No. It's EST (Electronic Spark Timing) that's controlled by the ESC (Electronic Spark Control) in the ECM. There's a little brown wire that's poking out of the wire loom near your heater box on the passenger side. Unplug it after the car's warm (well after it's been running a few minutes ).

220* isn't overheating. Our cars stock some with a 195* t-stat and the fan doesn't kick on until 220-225*, then it shuts off at 200*. This keeps the engine in the right temp range to keep emissions low. As I said, if the car runs like crap in this temp range, then other things are wrong, not the cooling system.

Does the fan kick on?

BTW, timing, with the EST wire (the brown one) disconnected is 0* BTDC. The computer takes care of that when you hook it back up.

Just make sure you turn the car off after it warms up to disconnect the EST wire, then start it afterwards. Once you get the timing set, shut the car off and hook the EST back up. It's not a bad idea to disconnect the negative battery cable for a few minutes to reset the ECM.

Don't do this before you check for codes though. If you don't know how to do that, look in the FAQ section at www.thirdgen.org

 

Hmm... This would make sense. I've only set the timing before when the engine was cold, not when its fully warmed up.

It's comforting to know that my engine isn't overheating. I was doing on average about 90mph on the highway today and the temp never once went over about 220 or the middle point on the gauge, and yes the fans come on. I've spent enough on a new radiator and fans so the cooling system had better NOT have been the problem!

I'll try adjusting the timing with the engine fully warmed up, around the 220 degree mark.


I'll let you know what happens, and thanks for the help.