Hey guys, I've been living with this problem for a while but today this problem made the car feel dangerous. It was a very hot day today and whenever the temperature guage climbs into the midrange (~210*) the car develops a bad surging/revving at idle and upon acceleration, falls on its face. Today it wouldn't even get out of its own way! Right around 2k RPM's is when the problem hits again as the car shifts into second. At high RPM's the car will pull ok. I have to put my foot to the floor and wait a few seconds for the car to respond (after some loud popping coming from under the car ) I have 101,000 miles on it and as far as I know the opti is original (have owned the car since 32,000 miles). Last summer I replaced the wires and plugs, and fuel filter. Could it be the opti? What I can't figure out is that it'll run great when the motor is cold, or in the normal operating range (180*)...

 

My car wasn't as bad but I did have an obvious power loss once fully warm. Popped in a 160* thermostat and the HPP III set the fan on/off temps alot lower. Now it runs real nice all the time and never goes over 175~180 even in heavy stop and go traffic. From the sound of it you may have more problems than a hot running motor. Have you gotten any SES light when running hot or is it just a dog w/out throwing codes?

Recently mine developed a stumble at low revs (1000-1500) with part throttle and ended up having the Optispark replaced -- warranty covered by selling dealer, thank God. Stumble is gone. My Opti went 83,600 miles, got dumped on by the water pump fall 2001 and an intake oil leak coating the back since I bought it at 62,500mi.

Good luck!

 

Nope, no codes have been thrown. Anyone else care to take a stab at it? I'm really not ready to ditch it and go buy an LS1 yet!

 

I would take a look at the top of the engine.Actually.the little hoses that run along side the pass side of the manifold,all wireing going to the iac,and wireing in general,in that area.On my 93 the map sensor is on top of the engine.It needs a good seal with a good gasket.Hope this helps.(don't forget to check those connectors,remember these cars are 10 years old and the wireing goes south.)My02

 

You know what My car started doing the same thing! and it only does it when its hot!. It used to do this about 3 years ago too, but it went away after I changed plugs, wires and cleaned the MAF. Does anyone out there know what it may be?or how did you guys fix your problem.. help us out.

 

Did you change the coil wire when you did the wires?

Start with the cheaper stuff. Swap out your coil for an aftermarket one.

If that doesn't help, get an opti.