Well I was given this car, a 1989 IROC-Z with a 350 TPI and the auto in it. It's in alright shape I suppose. Not quite as nice as my '98 Z28, but it's going to be my daily driver.

One problem I have is that it runs REALLY hot. I mean, it hits the red zone on the gauge more than I'd like to even count. Checked the thermostat, was fine, even replaced it. I noticed only 1 fan comes on and only when the temp reaches the line between 220 and 260. Then it shuts off at 220. Only ONE fan comes on. And I can't tell if it's in fast or slow speed.

The other problem I have is that the car runs fine at any part throttle position up to about 4800-5000rpm, then starts to sputter, and feel like its just not running right. It also does it at WOT, and backfires a little bit.

I'm gonna check the timing on the car to see if thats messed up. There is no SES light on in the car (the bulb does work, comes on when I turn the key) so I have no clue.

The car does have a SMALL cam in it and some shorty headers with a Catted Y and the O2 sensor is plugged in.

Thanks guys for any advice.

 

Which fan is coming on, the one on the driver's side or passenger side? Checked the coolant level? When was last tune up done?

 

How do you know it is really hot? I would take an Infra Red scanner and check what the temp is at the sender whcih is between exhaust ports 1 and 3 on the head. Then scan the radiator for cold spots. Make sure the gauge is reading what the temp is and make sure the radiator is doing it's job

 

yeah...has the radiator been flushed?

for the high rpm problem...could be a bad coil or wire....where it runs out of steam at the hi-rpm demand.

 

robg82 - my '89 GTA doesn't have the fan come on until 220 or just past it on the gauge. It's normal. Most if not all years of TPI engines do the same thing. GM did that for emmissions reasons. You can buy an aftermarket fan switch from JET or Hypertech with different fan on/off temps. Match one with the thermostat you want to run and you're good to go.