383 Running hot?

[the beast]

In the 1989 Blazer I just bought, it's got a 383 with the stock fuel injection system. It always runs hot. It doesn't overheat, but it runs up to about 250, then the t-stat opens and it drops to about 200. It cycles back and forth like this.

Any suggestions on how I can get this to run at a fairly constant, correct temp?

Anyone else run into these problems with the 383?

Thanks.

 

[dyeager535]

Sounds like a bad thermostat.

Of course you could be looking at a bad/incorrect gauge or temp sender as well.

Thermostats are a common problem though, Delco's come highly recommended, aftermarkets seem to have a high failure rate.

 

[6.2Blazer]

but it runs up to about 250, then the t-stat opens and it drops to about 200. It cycles back and forth like this.

Sounds like you might have answered your own question............based on that I would try a new thermostat as it sounds like the current one is opening way too slow.

 

[beastofablaze]

I agree about the t stat.

another thing to think about is fuel starvation...if the thing isn't getting enough to drink its gonna want to run hot no matter how good your thermostat is. I'd pull a spark plug or two just to be safe. stock fuel injection and a stroker means theres a good chance its running lean.

 

[dyeager535]

Good point...if the injection hasn't been modified for the larger engine, it's almost guaranteed that thing is running lean in certain conditions, which isn't good for the engine regardless of what the temp indication is.