1993Z28LT16SPD

I've got a 93' with a stock LT1, have had it since 97, now has 75K and sees about 3K as year. Have had all the typical issues over the years replacing the opti, ignition module, fuel pump over the past 5 years. Current problem started Wed when the car would not turn over in the morning. Came home that day, it started right up and ran for about 2 minutes, then died and would'nt restart for (several) hours. Everyday since, it will start right up and run for about 2 minutes, shut down and will not restart. Not getting an SES light.
Looking for some advice on what's the most likely, taking a shot at fixing it myself this time, tired of $pending for repairs over the years and it's not my daily driver so why not. Here's the most recent items that have been replaced:
- Idle Air Control Valve, Injectors & throttle body cleaned 3,500 miles ago (Chevy Dealer)
- Opti spark, ignition control module, - 8,500 miles ago
- EGR valve, Fuel filter - 9,000 miles ago
- Fuel Pump - 11,000 miles ago.

johnnyb

alternator

Bluovlh8er

are you serious?

johnnyb

uh... it wouldnt turn over, then it died after he finally got it started and wont restart =alternator

ss.slp.ls1

You can run your car with no alternator. If I'm not mistaken, if the alt is bad it will run the battery down till it dies, then it shouldn't restart at all.

I wonder if this is a problem with open/closed loop. No codes...guessing is no fun.

1993Z28LT16SPD

Yeah, I don't think it's the alternator either. It will start up on the first try on a given day, run for about 2-3 min then shut down. If you to restart it right away it will not restart. I've only tried right afterwards and several hrs later - usually will restart several hrs later and again run only a few minutes. However, the whole thing started when it just wouldn't start one morning at all, since then it hasn't done that. No issues before that at all

Greg88

check your fuel pressure, the gas tank could be full of rust causing the fuel pump to become faulty, its easy to check the fuel pressure. I would start there first. Good luck , Also, check your temperature sensor on the waterpump, i had one break off then the motor would run fine until it got warm, then it would spudder out and die.

mrmint69

I replaced my temp sensor and it has gone away for me. It doesn't make sense the car would just shut off, but it was under $10 and wasn't reading properly on my datalogs. The icm wouldn't be hot enough in my opinion so it must be something else.

1993Z28LT16SPD

I'll give it shot this weekend. I'm using a Haynes manual for reference I bought in 2000 that lacks a lot of details - anybody have any suggestions for a newer/better service manual? I don't want to get lost under there.

ss.slp.ls1

You have two temp sensors, one is right in front of the water pump, and the other is on the left hand side of the cylinder head on the driver side. They are both pretty easily accessable. You need to drain the coolant first. You just unclip the pigtail and unscrew the sensors. Screw the replacements in with thread locker. I don't know if these will cure your problem, but that's how to replace them.

mrmint69

You can get codes without a dash warning light. The one in the block is for the gauge in the car only. The one in the waterpump is the one the computer uses. I just unscrewed the old one with a drain pan below and quickly put the new one in while it was draining & not much came out. Just be sure the opti stays dry and you bleed the air out afterwards. The GM one has thread lock sealant on it already. Took me under 10 minutes and all i needed was one wrench and some fresh coolant for the little i lost.