markzzzz

New here, Hi to all. 97 Z28, rebuild with less than 1000 miles. Had ran smooth all of a sudden started rough idle and cutting off. After thinking of the dreaded optispark problem, (new one at rebuild) I checked for spark and had none. Before getting stupid and tearing it out I jumped it off with my truck and decided it might be the battery. Sure enough it checked bad. Got a new one and it started up fine but with a small miss. More checking and I found a burned up spark plug wire and replaced it. Started fine cold but poor when hot. Got codes read and had cps sensor and ect sensor fault. Found out ect sensor was a brass plug so I put the right sensor in and starts perfectly cold or hot but since then it seems to be running a lot hotter (210-230). I can manually turn on fans and it cools to @180 all by factory guage in car. Am I missing something or just paranoid? I still can't figure out cps sensor fault but it doesn't seem to be causing any issues.

Injuneer

The crank position sensor is only there to monitor for misfires... doesn't control the way the engine runs. Did you check to see if it was plugged in? If they were sloppy enough to replace the CLT sensor with a brass plug, maybe they didn't install the CKP sensor, or forgot to install the reluctor ring on the crank, or forgot to plug it in.

When you had the code for the missing coolant temp sensor in the water pump housing, the PCM defaulted to running the fans all the time. Normal that it would run cooler. Now that you have the correct sensor, the PCM turns both fans on at low speed at 226*F and at high speed at 235*F.

When do you see 210*F - on the highway at decent speeds? When do you see 235*F - sitting in traffic, long idle, etc.? Do you have a stock (180*F) thermostat? Has the PCM been reprogrammed?

markzzzz

180-200 moving,230 + at long idle or stop and go traffic. Stock thermostat and no pcm programming. Should I reset the pcm?

Injuneer

The only thing you can do when you "reset" the PCM is clear the long term fuel corrections, and the trouble codes. Will not affect the way the fans work.

Your "moving" temp is normal. The long idle is a bit on the high side. The engine was designed to run at 210*F, middle of the gauge. Wouldn't be unusual to see it go a bit above that in hot weather, stop 'n go traffic.

Check the two coolant temp sensors for accuracy:

Courtesy of Shoebox

4th Gen LT1 F-body Tech Articles

Has the radiator ever been flushed? Check in front of the radiator for obstructions (leaves, plastic bag). Check for damaged fan blades. Make sure the fan shroud on the rear of the radiator is intact. If you have an automatic trans, does that run hot? That would increase the heat load to the radiator, particularly at idle. Make sure you have the correct LT1 thermostat:

Courtesy of Shoebox

http://shbox.com/1/tstat.jpg

markzzzz

Long night at work complicated by a car this morning. Drove to work(around 20 miles) ran perfect, no temperature problem, all is good. Went to break around midnight and drove across the street to park and have a smoke, wouldn't start back up. Wouldn't jump off this morning. Acts like no spark. Going back later with freshly charged battery to try again. Is there anything that could be killing the battery when sitting or what am i missing? It's a m6 not auto by the way.

Injuneer

https://www.camaroz28.com/forums/lt1...nature-879835/

markzzzz

Using phone not laptop sorry about signature